Commission Implementing Regulation (EU) 2017/373 of 1 March 2017 laying down common requirements for providers of air traffic management/air navigation services and other air traffic management network functions and their oversight, repealing Regulation (EC) No 482/2008, Implementing Regulations (EU) No 1034/2011, (EU) No 1035/2011 and (EU) 2016/1377 and amending Regulation (EU) No 677/2011 (Text with EEA relevance) (c. 373)

ANNEX V U.K. SPECIFIC REQUIREMENTS FOR PROVIDERS OF METEOROLOGICAL SERVICES(Part-MET)

SUBPART A — ADDITIONAL ORGANISATION REQUIREMENTS FOR PROVIDERS OF METEOROLOGICAL SERVICES (MET.OR) U.K.

SECTION 1 — GENERAL REQUIREMENTS U.K.

MET.OR.100 Meteorological data and information U.K.

(a)

A meteorological services provider shall provide operators, flight crew members, air traffic services units, search and rescue services units, aerodrome operators, accident and incident investigation bodies, and other service providers and aviation entities with the meteorological information necessary for the performance of their respective functions, as determined by the competent authority.

(b)

A meteorological services provider shall confirm the operationally desirable accuracy of the information distributed for operations, including the source of such information, whilst also ensuring that such information is distributed in a timely manner and updated, as required.

MET.OR.105 Retention of meteorological information U.K.

(a)

A meteorological services provider shall retain meteorological information issued for a period of at least 30 days from the date of issue.

(b)

This meteorological information shall be made available, on request, for inquiries or investigations and, for these purposes, shall be retained until the inquiry or investigation is completed.

MET.OR.110 Meteorological information exchange requirements U.K.

A meteorological services provider shall ensure it has systems and processes in place, as well as access to suitable telecommunications facilities to:

(a)

enable the exchange of operational meteorological information with other meteorological services providers;

(b)

provide the required meteorological information to the users in a timely manner.

MET.OR.115 Meteorological bulletins U.K.

The meteorological services provider responsible for the area concerned shall provide meteorological bulletins to the relevant users, via the aeronautical fixed service or the internet.

[F1 MET.OR.120 Notification of discrepancies to the world area forecast centres (WAFCs) U.K.

The meteorological services provider using WAFS SIGWX in binary universal form for the representation of meteorological data (BUFR) code form shall notify the WAFC concerned immediately if significant discrepancies are detected or reported in respect of WAFS SIGWX forecasts concerning:

(a)

icing, turbulence, cumulonimbus clouds that are obscured, frequent, embedded, or occurring at a squall line, and sandstorms or dust storms;

(b)

volcanic eruptions or a release of radioactive materials into the atmosphere of significance to aircraft operations.]

Textual Amendments

F1 Substituted by Commission Implementing Regulation (EU) 2020/469 of 14 February 2020 amending Regulation (EU) No 923/2012, Regulation (EU) No 139/2014 and Regulation (EU) 2017/373 as regards requirements for air traffic management/air navigation services, design of airspace structures and data quality, runway safety and repealing Regulation (EC) No 73/2010 (Text with EEA relevance).

SECTION 2 — SPECIFIC REQUIREMENTS U.K.

Chapter 1 — Requirements for aeronautical meteorological stations U.K.

MET.OR.200 Meteorological reports and other information U.K.

(a)

An aeronautical meteorological station shall disseminate:

(1)

local routine reports at fixed intervals, only for dissemination at the aerodrome of origin;

(2)

local special reports, only for dissemination at the aerodrome of origin;

(3)

METAR at half-hourly intervals at aerodromes serving scheduled international commercial air transport operations for dissemination beyond the aerodrome of origin.

(b)

An aeronautical meteorological station shall inform the air traffic service units and aeronautical information service of an aerodrome of changes in the serviceability status of the automated equipment used for assessing runway visual range.

(c)

An aeronautical meteorological station shall report to the associated air traffic services unit, aeronautical information services unit, and meteorological watch office the occurrence of pre-eruption volcanic activity, volcanic eruptions and volcanic ash cloud.

(d)

An aeronautical meteorological station shall establish a list of criteria to provide local special reports in consultation with the appropriate ATS units, operators and others concerned.

MET.OR.205 Reporting of meteorological elements U.K.

[F1 An aeronautical meteorological station shall report:]

(a)

surface wind direction and speed;

(b)

visibility;

(c)

runway visual range, if applicable;

(d)

present weather at the aerodrome and its vicinity;

(e)

clouds;

(f)

air temperature and dew point temperature;

(g)

atmospheric pressure;

(h)

supplementary information when applicable.

Where authorised by the competent authority, at aerodromes not serving scheduled international commercial air transport operations, an aeronautical meteorological station may report only a subset of the meteorological elements as relevant to the types of flights at that aerodrome. This data set shall be published in the aeronautical information publication.

MET.OR.210 Observing meteorological elements U.K.

[F1 An aeronautical meteorological station shall observe and/or measure:]

(a)

surface wind direction and speed;

(b)

visibility;

(c)

runway visual range, if applicable;

(d)

present weather at the aerodrome and its vicinity;

(e)

clouds;

(f)

air temperature and dew point temperature;

(g)

atmospheric pressure;

(h)

supplementary information, when applicable:

Where authorized by the competent authority, at aerodromes not serving scheduled international commercial air transport operations, an aeronautical meteorological station may observe and/or measure only a subset of the meteorological elements as relevant to the types of flights at that aerodrome. This data set shall be published in the aeronautical information publication.

Chapter 2 — Requirements for aerodrome meteorological offices U.K.

MET.OR.215 Forecasts and other information U.K.

An aerodrome meteorological office shall:

(a)

prepare and/or obtain forecasts and other relevant meteorological information necessary for the performance of its respective functions for flights with which it is concerned, as determined by the competent authority;

(b)

provide forecasts and/or warnings for local meteorological conditions on aerodromes for which it is responsible;

(c)

keep the forecasts and warnings under continuous review and issue amendments promptly when necessary, and cancel any forecast of the same type previously issued for the same place and for the same period of validity or part thereof;

(d)

provide briefing, consultation and flight documentation to flight crew members and/or other flight operations personnel;

(e)

provide climatological information;

(f)

provide its associated air traffic services unit, aeronautical information service unit and meteorological watch office with information received on pre-eruption volcanic activity, a volcanic eruption or volcanic ash cloud;

(g)

provide, if applicable, meteorological information to search and rescue services units and maintain liaison with the search and rescue services unit(s) throughout a search and rescue operation;

(h)

provide meteorological information to relevant aeronautical information services units, as necessary, for the conduct of their functions;

(i)

prepare and/or obtain forecast and other relevant meteorological information necessary for the performance of the ATS units functions in accordance with point MET.OR.242;

(j)

provide its associated air traffic services unit, aeronautical information service unit and meteorological watch offices with information received on the release of radioactive materials into the atmosphere.

MET.OR.220 Aerodrome forecasts U.K.

(a)

An aerodrome meteorological office shall issue aerodrome forecasts as a TAF at a specified time.

(b)

When issuing TAF, the aerodrome meteorological office shall ensure that not more than one TAF is valid at an aerodrome at any given time.

MET.OR.225 Forecasts for landing U.K.

(a)

An aerodrome meteorological office shall prepare forecasts for landing as determined by the competent authority.

(b)

This forecast for landing shall be issued in the form of a TREND forecast.

(c)

The period of validity of a TREND forecast shall be 2 hours from the time of the report which forms part of the landing forecast.

MET.OR.230 Forecasts for take-off U.K.

An aerodrome meteorological office shall:

(a)

prepare forecasts for take-off as determined by the competent authority;

(b)

supply forecasts for take-off to operators and flight crew members on request within the 3 hours before the expected time of departure.

MET.OR.235 Aerodrome warnings and wind shear warnings and alerts U.K.

An aerodrome meteorological office shall:

(a)

provide aerodrome warnings information;

(b)

prepare wind shear warnings for aerodromes where wind shear is considered a factor, in accordance with local arrangements with the appropriate ATS unit and operators concerned;

(c)

issue, at aerodromes where wind shear is detected by automated, ground-based, wind shear remote-sensing or detection equipment, wind shear alerts generated by these systems;

(d)

cancel warnings when the conditions are no longer occurring and/or no longer expected to occur at the aerodrome.

MET.OR.240 Information for use by operator or flight crew U.K.

(a)

An aerodrome meteorological office shall provide operators and flight crew members with:

(1)

forecasts, originating from the WAFS, of the elements listed in points (1) and (2) of point MET.OR.275(a);

(2)

[F1 METAR or SPECI, including TREND, TAF or amended TAF for the aerodromes of departure and intended landing, and for take-off, en-route and destination alternate aerodromes;]

(3)

aerodrome forecasts for take-off;

(4)

SIGMET and special air-reports relevant to the whole route;

(5)

volcanic ash and tropical cyclone advisory information relevant to the whole route;

(6)

[F1 area forecasts for low-level flights in chart form prepared in support of the issuance of an AIRMET, and an AIRMET for low-level flights relevant to the whole route;]

(7)

aerodrome warnings for the local aerodrome;

(8)

meteorological satellite images;

(9)

ground-based weather radar information.

(b)

Whenever the meteorological information to be included in the flight documentation differs materially from that made available for flight planning, the aerodrome meteorological office shall:

(1)

advise immediately the operator or flight crew concerned;

(2)

if practicable, provide the revised meteorological information in agreement with the operator.

MET.OR.242 Information to be provided to air traffic services units U.K.

(a)

[F1 An aerodrome meteorological office shall provide, as necessary, its associate aerodrome control tower and AFIS unit with:

(1)

local routine report, local special report, METAR, TAF and TREND and amendments thereto;

(2)

SIGMET, AIRMET, wind shear warnings and alerts and aerodrome warnings;

(3)

any additional meteorological information agreed upon locally, such as forecasts of surface wind for the determination of possible runway changes;

(4)

information received on volcanic ash cloud, for which a SIGMET has not already been issued, as agreed between the aerodrome meteorological office and the aerodrome control tower or the AFIS unit concerned;

(5)

information received on pre-eruption volcanic activity and/or a volcanic eruption as agreed between the aerodrome meteorological office and the aerodrome control tower or the AFIS unit concerned.]

(b)

An aerodrome meteorological office shall provide its associate approach control unit with:

(1)

[F1 local routine report, local special report, METAR, TAF and TREND and amendments thereto;

(2)

SIGMET, AIRMET, wind shear warnings and alerts, appropriate special air-reports and aerodrome warnings;]

(3)

any additional meteorological information agreed upon locally;

(4)

information received on volcanic ash cloud, for which a SIGMET has not already been issued, as agreed between the aerodrome meteorological office and the approach control unit concerned;

(5)

information received on pre-eruption volcanic activity and/or a volcanic eruption as agreed between the aerodrome meteorological office and the approach control unit concerned.

Chapter 3 — Requirements for meteorological watch offices U.K.

MET.OR.245 Meteorological watch and other information U.K.

Within its area of responsibility, the meteorological watch office shall:

(a)

maintain continuous watch over meteorological conditions affecting flight operations;

(b)

[F1 coordinate with the organisation responsible for the provision of NOTAM and/or ASHTAM to ensure that meteorological information on volcanic ash included in SIGMET and NOTAM and/or ASHTAM is consistent;]

(c)

coordinate with selected volcano observatories to ensure that information on volcanic activity is received in an efficient and timely manner;

(d)

provide its associated VAAC with information received on pre-eruption volcanic activity, a volcanic eruption and volcanic ash cloud for which a SIGMET has not already been issued;

(e)

provide its aeronautical information service units with information received on the release of radioactive materials into the atmosphere in the area or adjacent areas for which it maintains watch and for which a SIGMET has not already been issued;

(f)

provide its associated area control centre and flight information centre (ACC/FIC), as necessary, with relevant:

(1)

[F1 METAR, including current pressure data for aerodromes and other locations, TAF, TREND and amendments thereto;

(2)

forecasts of upper winds, upper-air temperatures and significant en-route weather phenomena and amendments thereto, SIGMET, AIRMET and appropriate special air-reports;]

(3)

any other meteorological information required by the ACC/FIC to meet requests from aircraft in flight;

(4)

information received on volcanic ash cloud, for which a SIGMET has not already been issued, as agreed between the meteorological watch office and the ACC/FIC;

(5)

information received concerning the release of radioactive material into the atmosphere, as agreed between the meteorological watch office and the ACC/FIC;

(6)

[F1 tropical cyclone advisory issued by a TCAC in its area of responsibility;

(7)

volcanic ash advisory issued by a VAAC in its area of responsibility;

(8)

information received on pre-eruption volcanic activity and/or a volcanic eruption as agreed between the meteorological watch office and the ACC/FIC;]

(g)

[F2 when available, provide the relevant air traffic services units, in accordance with local agreement, with information regarding the release into the atmosphere of toxic chemicals which could affect the airspace used by flights within their area of responsibility.]

Textual Amendments

F2 Inserted by Commission Implementing Regulation (EU) 2020/469 of 14 February 2020 amending Regulation (EU) No 923/2012, Regulation (EU) No 139/2014 and Regulation (EU) 2017/373 as regards requirements for air traffic management/air navigation services, design of airspace structures and data quality, runway safety and repealing Regulation (EC) No 73/2010 (Text with EEA relevance).

[F1 MET.OR.250 SIGMET U.K.

A meteorological watch office shall:

(a)

provide and disseminate SIGMET;

(b)

ensure that the SIGMET is cancelled when the phenomena are no longer occurring or are no longer expected to occur in the area covered by the SIGMET;

(c)

ensure that the period of validity of a SIGMET is not more than 4 hours, and in the special case of SIGMET for volcanic ash cloud and tropical cyclones, it shall be extended up to 6 hours;

(d)

ensure that SIGMET are issued not more than 4 hours before the commencement of the period of validity. In the special case of SIGMET for volcanic ash cloud and tropical cyclones, SIGMET shall be issued as soon as practicable, but not more than 12 hours before the commencement of the period of validity, and updated at least every 6 hours.]

[F1 MET.OR.255 AIRMET U.K.

A meteorological watch office shall:

(a)

provide and disseminate AIRMET when the competent authority has determined that the density of traffic operating below flight level 100, or up to flight level 150 in mountainous areas, or higher, where necessary, warrants the issue and dissemination of area forecasts for such operations;

(b)

cancel the AIRMET when the phenomena are no longer occurring or are no longer expected to occur in the area;

(c)

ensure that the period of validity of an AIRMET is not more than 4 hours.]

MET.OR.260 Area forecasts for low-level flights U.K.

A meteorological watch office shall:

(a)

provide area forecast for low-level flights when the density of traffic operating below flight level 100, or up to flight level 150 in mountainous areas, or higher, where necessary, warrants the routine issue and dissemination of area forecasts for such operations;

(b)

ensure that the frequency of issue, the form, and the fixed time or period of validity of area forecast for low-level flights and the criteria for amendments thereto, are as determined by the competent authority;

(c)

[F1 ensure that area forecasts for low-level flights prepared in support of the issuance of an AIRMET are issued every 6 hours for a period of validity of 6 hours and transmitted to the meteorological watch offices concerned not later than 1 hour prior to the beginning of their validity period.]

Chapter 4 — Requirements for volcanic ash advisory centre (VAAC) U.K.

MET.OR.265 Volcanic ash advisory centre responsibilities U.K.

In its area of responsibility, the VAAC shall:

(a)

when a volcano has erupted, or is expected to erupt, or volcanic ash is reported, provide advisory information regarding the extent and forecast movement of the volcanic ash cloud to:

(1)

the European aviation crisis coordination cell;

(2)

meteorological watch offices serving flight information regions in its area of responsibility which may be affected;

(3)

operators, area control centres, and flight information centres serving flight information regions in its area of responsibility which may be affected;

(4)

[F1 WAFCs, international OPMET databanks, international NOTAM offices and centres designated by regional air navigation agreement for the operation of the aeronautical fixed service internet-based services;]

(5)

other VAACs whose areas of responsibility may be affected.

(b)

coordinate with selected volcano observatories to ensure that information on volcanic activity is received in an efficient and timely manner;

(c)

provide the advisory meteorological information referred to in point (a) at least every 6 hours until such time as the volcanic ash cloud is no longer identifiable from satellite data, no further meteorological reports of volcanic ash are received from the area and no further eruptions of the volcano are reported; and

(d)

maintain a 24-hour watch.

Chapter 5 — Requirements for tropical cyclone advisory centre (TCAC) U.K.

MET.OR.270 Tropical cyclone advisory centre responsibilities U.K.

[F1 A TCAC shall provide:]

(a)

advisory information concerning the position of the cyclone centre, its direction and speed of movement, central pressure and maximum surface wind near the centre in abbreviated plain language to:

(1)

meteorological watch offices in its area of responsibility;

(2)

other TCACs whose areas of responsibility may be affected;

(3)

[F1 WAFCs, international OPMET databanks and centres responsible for the operation of the aeronautical fixed service internet-based services;]

(b)

updated advisory information to meteorological watch offices for each tropical cyclone, as necessary, but at least every 6 hours.

Chapter 6 — Requirements for world area forecast centre (WAFC) U.K.

MET.OR.275 World area forecast centre responsibilities U.K.

(a)

The WAFC shall provide, in a digital form:

(1)

gridded global forecasts of:

(i)

upper wind;

(ii)

upper-air temperature and humidity;

(iii)

geopotential altitude of flight levels;

(iv)

flight level and temperature of tropopause;

(v)

direction, speed and flight level of maximum wind;

(vi)

cumulonimbus clouds;

(vii)

icing;

(viii)

turbulence;

(2)

global forecasts of significant weather (SIGWX) phenomena, including volcanic activity and release of radioactive materials.

(b)

The WAFC shall ensure that world area forecast system products in digital form are transmitted using binary data communications techniques.

SUBPART B — TECHNICAL REQUIREMENTS FOR PROVIDERS OF METEOROLOGICAL SERVICES (MET.TR) U.K.

SECTION 1 — GENERAL REQUIREMENTS U.K.

MET.TR.115 Meteorological bulletins U.K.

(a)

Meteorological bulletins shall contain a heading consisting of:

(1)

an identifier of four letters and two figures;

(2)

the ICAO four-letter location indicator corresponding to the geographical location of the meteorological service provider originating or compiling the meteorological bulletin;

(3)

a day-time group;

(4)

if required, a three-letter indicator.

(b)

Meteorological bulletins containing operational meteorological information to be transmitted via the AFTN shall be encapsulated in the text part of the AFTN message format.

SECTION 2 — SPECIFIC REQUIREMENTS U.K.

Chapter 1 — Technical requirements for aeronautical meteorological stations U.K.

MET.TR.200 Meteorological reports and other information U.K.

(a)

[F1 Local routine report, local special report and METAR shall contain the following elements in the order indicated:]

(1)

identification of the type of report;

(2)

location indicator;

(3)

time of the observation;

(4)

identification of an automated or missing report, when applicable;

(5)

surface wind direction and speed;

(6)

visibility;

(7)

runway visual range, when the reporting criteria are met;

(8)

present weather;

(9)

cloud amount, cloud type only for cumulonimbus and towering cumulus clouds and height of cloud base or, where measured, vertical visibility;

(10)

air temperature and dew-point temperature;

(11)

QNH and, when applicable, in local routine and local special reports, QFE;

(12)

supplementary information, when applicable.

(b)

[F1 In local routine report and local special report:]

(1)

if the surface wind is observed from more than one location along the runway, the locations for which these values are representative shall be indicated;

(2)

when there is more than one runway in use and the surface wind related to these runways is observed, the available wind values for each runway shall be given, and the runways to which the values refer shall be reported;

(3)

when variations from the mean wind direction are reported in accordance with point MET.TR.205(a)(3)(ii)(B), the two extreme directions between which the surface wind has varied shall be reported;

(4)

when variations from the mean wind speed (gusts) are reported in accordance with point MET.TR.205(a)(3)(iii), they shall be reported as the maximum and minimum values of the wind speed attained.

(c)

METAR

(1)

METAR shall be issued in accordance with the template shown in Appendix 1 and disseminated in the METAR code form prescribed by the World Meteorological Organisation.

(2)

If disseminated in digital form, METAR shall be:

(i)

formatted in accordance with a globally interoperable information exchange model and shall use geography markup language (GML);

(ii)

accompanied by the appropriate metadata.

(3)

METAR shall be filed for transmission not later than 5 minutes after the actual time of observation.

(d)

Information on visibility, runway visual range, present weather and cloud amount, cloud type and height of cloud base shall be replaced in all meteorological reports by the term ‘CAVOK’ when the following conditions occur simultaneously at the time of observation:

(1)

visibility, 10 km or more, and the lowest visibility is not reported;

(2)

no cloud of operational significance;

(3)

no weather of significance to aviation.

(e)

The list of criteria to provide local special reports shall include:

(1)

those values which most closely correspond to the operating minima of the operators using the aerodrome;

(2)

those values which satisfy other local requirements of the ATS units and of the operators;

(3)

an increase in air temperature of 2 °C or more from that given in the latest local report, or an alternative threshold value as agreed between the meteorological service providers, the appropriate ATS unit and the operators concerned;

(4)

the available supplementary information concerning the occurrence of significant meteorological conditions in the approach and climb-out areas;

(5)

when noise abatement procedures are applied and the variation from the mean surface wind speed has changed by 5 kt (2,5 m/s) or more from that at the time of the latest local report, the mean speed before and/or after the change being 15 kt (7,5 m/s) or more;

(6)

when the mean surface wind direction has changed by 60° or more from that given in the latest report, the mean speed before and/or after the change being 10 kt (5 m/s) or more;

(7)

when the mean surface wind speed has changed by 10 kt (5 m/s) or more from that given in the latest local report;

(8)

when the variation from the mean surface wind speed (gusts) has changed by 10 kt (5 m/s) or more from that at the time of the latest local report, the mean speed before and/or after the change being 15 kt (7,5 m/s) or more;

(9)

when the onset, cessation or change in intensity of any of the following weather phenomena occurs:

(i)

freezing precipitation;

(ii)

moderate or heavy precipitation, including showers thereof; and

(iii)

thunderstorm, with precipitation;

(10)

when the onset or cessation of any of the following weather phenomena occurs:

(i)

freezing fog;

(ii)

thunderstorm, without precipitation;

(11)

when the amount of a cloud layer below 1 500 ft (450 m) changes:

(i)

from scattered (SCT) or less to broken (BKN) or overcast (OVC); or

(ii)

from BKN or OVC to SCT or less.

(f)

When so agreed between the meteorological services provider and the competent authority, local special reports shall be issued whenever the following changes occur:

(1)

when the wind changes through values of operational significance. The threshold values shall be established by the meteorological service provider in consultation with the appropriate ATS unit and operators concerned, taking into account changes in the wind which would:

(i)

require a change in runway(s) in use;

(ii)

indicate that the runway tailwind and crosswind components have changed through values representing the main operating limits for typical aircraft operating at the aerodrome;

(2)

when the visibility is improving and changes to or passes through one or more of the following values, or when the visibility is deteriorating and passes through one or more of the following values:

(i)

800, 1 500 or 3 000 m;

(ii)

5 000 m, in cases where significant numbers of flights are operated in accordance with the visual flight rules;

(3)

when the runway visual range is improving and changes to or passes through one or more of the following values, or when the runway visual range is deteriorating and passes through one or more of the following values: 50, 175, 300, 550 or 800 m;

(4)

when the onset, cessation or change in intensity of any of the following weather phenomena occurs:

(i)

dust storm;

(ii)

sandstorm;

(iii)

funnel cloud (tornado or waterspout);

(5)

when the onset or cessation of any of the following weather phenomena occurs:

(i)

low drifting dust, sand or snow;

(ii)

blowing dust, sand or snow;

(iii)

squall;

(6)

when the height of base of the lowest cloud layer of BKN or OVC extent is lifting and changes to or passes through one or more of the following values, or when the height of base of the lowest cloud layer of BKN or OVC extent is lowering and passes through one or more of the following values:

(i)

100, 200, 500 or 1 000 ft (30, 60, 150 or 300 m);

(ii)

1 500 ft (450 m), in cases where significant numbers of flights are operated in accordance with the visual flight rules;

(7)

when the sky is obscured and the vertical visibility is improving and changes to or passes through one or more of the following values, or when the vertical visibility is deteriorating and passes through one or more of the following values: 100, 200, 500 or 1 000 ft (30, 60, 150 or 300 m);

(8)

any other criteria based on local aerodrome operating minima, as agreed between the meteorological services providers and the operators.

MET.TR.205 Reporting of meteorological elements U.K.

(a) Surface wind direction and speed U.K.

(1)

[F1 In local routine report, local special report and METAR, the surface wind direction and speed shall be reported in steps of 10 degrees true and 1 kt (0,5 m/s) respectively.]

(2)

Any observed value that does not fit the reporting scale in use shall be rounded to the nearest step in the scale.

(3)

[F1 In local routine report, local special report and METAR:]

(i)

the units of measurement used for the wind speed shall be indicated;

(ii)

variations from the mean wind direction during the past 10 minutes shall be reported as follows, if the total variation is 60° or more, alternatively:

(A)

when the total variation is 60° or more and less than 180° and the wind speed is 3 kt (1,5 m/s) or more, such directional variations shall be reported as the two extreme directions between which the surface wind has varied;

(B)

when the total variation is 60° or more and less than 180° and the wind speed is less than 3 kt (1,5 m/s), the wind direction shall be reported as variable with no mean wind direction;

(C)

when the total variation is 180° or more, the wind direction shall be reported as variable with no mean wind direction;

(iii)

variations from the mean wind speed (gusts), during the past 10 minutes shall be reported when the maximum wind speed exceeds the mean speed by, alternatively:

(A)

[F1 5 kt (2,5 m/s) or more in local routine report and local special report when noise abatement procedures are applied;]

(B)

10 kt (5 m/s) or more otherwise;

(iv)

when a wind speed of less than 1 kt (0,5 m/s) is reported, it shall be indicated as calm;

(v)

when a wind speed of 100 kt (50 m/s) or more is reported, it shall be indicated to be more than 99 kt (49 m/s);

(vi)

when variations from the mean wind speed (gusts) are reported in accordance with point MET.TR.205(a), the maximum value of the wind speed attained shall be reported;

(vii)

when the 10-minute period includes a marked discontinuity in the wind direction and/or speed, only variations from the mean wind direction and mean wind speed occurring since the discontinuity shall be reported.

(b) Visibility U.K.

(1)

[F1 In local routine report, local special report and METAR, the visibility shall be reported in steps of 50 m when the visibility is less than 800 m; in steps of 100 m when it is 800 m or more, but less than 5 km; in kilometre steps when the visibility is 5 km or more, but less than 10 km; and it shall be given as 10 km when the visibility is 10 km or more, except when the conditions for the use of CAVOK apply.]

(2)

Any observed value which does not fit the reporting scale in use shall be rounded down to the nearest lower step in the scale.

(3)

[F1 In local routine report and local special report, visibility along the runway or runways shall be reported together with the units of measurement used to indicate visibility.]

(c) Runway visual range (RVR) U.K.

(1)

[F1 In local routine report, local special report and METAR, the RVR shall be reported in steps of 25 m when it is less than 400 m; in steps of 50 m when it is between 400 and 800 m; and in steps of 100 m when it is more than 800 m.]

(2)

Any observed value which does not fit the reporting scale in use shall be rounded down to the nearest lower step in the scale.

(3)

[F1 In local routine report, local special report and METAR:

(i)

when the RVR is above the maximum value that can be determined by the system in use, it shall be reported using the abbreviation ‘ ABV ’ in local routine report and local special report, and the abbreviation ‘ P ’ in METAR followed by the maximum value that can be determined by the system;

(ii)

when the RVR is below the minimum value that can be determined by the system in use, it shall be reported using the abbreviation ‘ BLW ’ in local routine report and local special report, and the abbreviation ‘ M ’ in METAR, followed by the minimum value that can be determined by the system.]

(4)

[F1 In local routine report and local special report:]

(i)

the units of measurement used shall be included;

(ii)

if the RVR is observed from only one location along the runway, such as the touchdown zone, it shall be included without any indication of location;

(iii)

if the RVR is observed from more than one location along the runway, the value representative of the touchdown zone shall be reported first, followed by the values representative of the mid-point and stop-end, and the locations for which these values are representative shall be indicated;

(iv)

when there is more than one runway in use, the available RVR values for each runway shall be reported, and the runways to which the values refer shall be indicated.

(d) Present weather phenomena U.K.

(1)

[F1 In local routine report and local special report, observed present weather phenomena shall be reported in terms of type and characteristics and qualified with respect to intensity, as appropriate.]

(2)

In METAR, observed present weather phenomena shall be reported in terms of type and characteristics and qualified with respect to intensity or proximity to the aerodrome, as appropriate.

(3)

[F1 In local routine report, local special report and METAR, the following characteristics of present weather phenomena, as necessary, shall be reported using their respective abbreviations and relevant criteria, as appropriate:]

(i)

Thunderstorm (TS)

Used to report a thunderstorm with precipitation. When thunder is heard or lightning is detected at the aerodrome during the 10-minute period preceding the time of observation but no precipitation is observed at the aerodrome, the abbreviation ‘TS’ shall be used without qualification.

(ii)

Freezing (FZ)

Supercooled water droplets or precipitation, used with types of present weather phenomena in accordance with Appendix 1.

(4)

[F1 In local routine report, local special report and METAR:]

(i)

one or more, up to a maximum of three, of the present weather abbreviations shall be used, as necessary, together with an indication, where appropriate, of the characteristics and intensity or proximity to the aerodrome, so as to convey a complete description of the present weather of significance to flight operations;

(ii)

the indication of intensity or proximity, as appropriate, shall be reported first followed respectively by the characteristics and the type of weather phenomena;

(iii)

where two different types of weather are observed, they shall be reported in two separate groups, where the intensity or proximity indicator refers to the weather phenomenon which follows the indicator. However, different types of precipitation occurring at the time of observation shall be reported as one single group with the dominant type of precipitation reported first and preceded by only one intensity qualifier which refers to the intensity of the total precipitation.

(e) Clouds U.K.

(1)

[F1 In local routine report, local special report and METAR, the height of cloud base shall be reported in steps of 100 ft (30 m) up to 10 000 ft ( 3 000 m) and in steps of 1 000 ft (300 m) above 10 000 ft ( 3 000 m).]

(2)

Any observed value which does not fit the reporting scale in use shall be rounded down to the nearest lower step in the scale.

(3)

[F1 In local routine report and local special report:]

(i)

the units of measurement used for the height of cloud base and vertical visibility shall be indicated;

(ii)

when there is more than one runway in use and the heights of cloud bases are observed by instruments for these runways, the available heights of cloud bases for each runway shall be reported, and the runways to which the values refer shall be indicated.

(f) Air temperature and dew-point temperature U.K.

(1)

[F1 In local routine report, local special report and METAR, the air temperature and the dew-point temperature shall be reported in steps of whole degrees Celsius.]

(2)

Any observed value which does not fit the reporting scale in use shall be rounded to the nearest whole degree Celsius, with observed values involving 0,5° rounded up to the next higher whole degree Celsius.

(3)

[F1 In local routine report, local special report and METAR, a temperature below 0 °C shall be identified.]

(g) Atmospheric pressure U.K.

(1)

[F1 In local routine report, local special report and METAR, the QNH and QFE shall be computed in tenths of hectopascals and reported therein in steps of whole hectopascals, using four digits.]

(2)

Any observed value which does not fit the reporting scale in use shall be rounded down to the nearest lower whole hectopascal.

(3)

[F1 In local routine report and local special report:]

(i)

QNH shall be included;

(ii)

QFE shall be included if required by users or, if so agreed locally between the provider of meteorological services, the ATS unit and the operators concerned, on a regular basis;

(iii)

the units of measurement used for QNH and QFE values shall be included;

(iv)

if QFE values are required for more than one runway, the required QFE values for each runway shall be reported, and the runway(s) to which the values refer shall be indicated.

(4)

In METAR, only QNH values shall be included.

MET.TR.210 Observing meteorological elements U.K.

The following meteorological elements shall be observed and/or measured with specified accuracy and disseminated by automatic or semi-automatic meteorological observing system.

(a) Surface wind direction and speed U.K.

The mean direction and the mean speed of the surface wind shall be measured, as well as significant variations of the wind direction and speed (gusts), and reported in degrees true and knots, respectively.

(1) Siting U.K.

The meteorological instrument used to measure surface wind direction and speed shall be situated in such a way as to provide data which is representative of the area for which the measurements are required.

(2) Display U.K.

Surface wind displays relating to each sensor shall be located in the meteorological station. The displays in the meteorological station and in the air traffic services units shall relate to the same sensors, and where separate sensors are required, the displays shall be clearly marked to identify the runway and section of runway monitored by each sensor.

(3) Averaging U.K.

The averaging period for surface wind observations shall be:

(i)

[F1 2 minutes for local routine report and local special report and for wind displays in ATS units;]

(ii)

10 minutes for METAR, except that when the 10-minute period includes a marked discontinuity in the wind direction and/or speed; only data occurring after the discontinuity shall be used for obtaining mean values; hence, the time interval in these circumstances shall be correspondingly reduced.

(b) Visibility U.K.

(1) The visibility shall be measured or observed, and reported in metres or kilometres. U.K.

(2) Siting U.K.

The meteorological instrument used to measure visibility shall be situated in such a way as to supply data which is representative of the area for which the measurements are required.

(3) Displays U.K.

When instrumented systems are used for the measurement of visibility, visibility displays relating to each sensor shall be located in the meteorological station. The displays in the meteorological station and in the air traffic services units shall relate to the same sensors, and where separate sensors are required, the displays shall be clearly marked to identify the area monitored by each sensor.

(4) Averaging U.K.

The averaging period shall be 10 minutes for METAR, except that when the 10-minute period immediately preceding the observation includes a marked discontinuity in the visibility, only those values occurring after the discontinuity shall be used for obtaining mean values.

(c) Runway visual range (RVR) U.K.

(1) Siting U.K.

The meteorological instrument used to assess the RVR shall be situated in such a way as to provide data which is representative of the area for which the observations are required.

(2) Instrumented systems U.K.

Instrumented systems based on transmissometers or forward-scatter meters shall be used to assess RVR on runways intended for Categories II and III instrument approach and landing operations, and for Category I instrument approach and landing operations as determined by the competent authority.

(3) Display U.K.

Where the RVR is determined by instrumented systems, one display or more, if required, shall be located in the meteorological station. The displays in the meteorological station and in the air traffic services units shall relate to the same sensors, and where separate sensors are required, the displays shall be clearly marked to identify the runway and section of runway monitored by each sensor.

(4) Averaging U.K.

(i)

Where instrumented systems are used for the assessment of the RVR, their output shall be updated at least every 60 seconds to permit the provision of current, representative values.

(ii)

The averaging period for RVR values shall be:

(A)

[F1 1 minute for local routine report and local special report and for RVR displays in ATS units;]

(B)

10 minutes for METAR, except that when the 10-minute period immediately preceding the observation includes a marked discontinuity in RVR values; then only those values occurring after the discontinuity shall be used for obtaining mean values.

(d) Present weather phenomena U.K.

(1) The following present weather phenomena shall be reported, as a minimum: rain, drizzle, snow and freezing precipitation, including intensity thereof, haze, mist, fog, freezing fog and thunderstorms, including thunderstorms in the vicinity. U.K.

(2) Siting U.K.

The meteorological instrument used to measure present weather at the aerodrome and its vicinity shall be situated in such a way as to provide data which is representative of the area for which the measurements are required.

(e) Clouds U.K.

(1) Cloud amount, cloud type and height of cloud base shall be observed and reported as necessary to describe the clouds of operational significance. When the sky is obscured, vertical visibility shall be observed and reported, where measured, instead of cloud amount, cloud type and height of cloud base. The height of cloud base and vertical visibility shall be reported in feet. U.K.

(2) Siting U.K.

The meteorological instrument used to measure clouds amount and height shall be situated in such a way as to provide data which is representative of the area for which the measurements are required.

(3) Display U.K.

When automated equipment is used for the measurement of the height of cloud base, at least one display shall be located in the meteorological station. The displays in the meteorological station and in the air traffic services units shall relate to the same sensors, and where separate sensors are required, the displays shall be clearly marked to identify the area monitored by each sensor.

(4) Reference level U.K.

(i)

The height of cloud base shall be reported above aerodrome elevation.

(ii)

When a precision approach runway in use has a threshold elevation of 50 ft (15 m) or more below the aerodrome elevation, local arrangements shall be made in order that the height of cloud bases reported to arriving aircraft shall refer to the threshold elevation.

(iii)

In the case of reports from offshore structures, the height of cloud base shall be given above mean sea level.

(f) Air temperature and dew-point temperature U.K.

(1)

The air temperature and dew-point temperature shall be measured, displayed and reported in degrees Celsius.

(2)

When automated equipment is used for the measurement of air temperature and dew-point temperature, the displays shall be located in the meteorological station. The displays in the meteorological station and in the air traffic services units shall relate to the same sensors.

(g) Atmospheric pressure U.K.

(1) The atmospheric pressure shall be measured, and QNH and QFE values shall be computed and reported in hectopascals. U.K.

(2) Display U.K.

(i)

When automated equipment is used for the measurement of atmospheric pressure, QNH and, if required in accordance with point MET.TR.205(g)(3)(ii), QFE displays relating to the barometer shall be located in the meteorological station with corresponding displays in the appropriate air traffic services units.

(ii)

When QFE values are displayed for more than one runway, the displays shall be clearly marked to identify the runway to which the QFE value displayed refers.

(3) Reference level U.K.

A reference level for the computation of QFE shall be used.

Chapter 2 — Technical requirements for aerodrome meteorological offices U.K.

MET.TR.215 Forecast and other information U.K.

(a)

Meteorological information for operators and flight crew members shall:

(1)

cover the flight in respect of time, altitude and geographical extent;

(2)

relate to appropriate fixed times or periods of time;

(3)

extend to the aerodrome of intended landing, also covering the meteorological conditions expected between the aerodrome of intended landing and alternate aerodromes designated by the operator;

(4)

be up to date.

(b)

Meteorological information provided to rescue coordination centres shall include the meteorological conditions that existed in the last known position of a missing aircraft and along the intended route of that aircraft with particular reference to elements which are not being distributed routinely.

(c)

Meteorological information provided to aeronautical information services units shall include:

(1)

information on meteorological service intended for inclusion in the aeronautical information publication(s) concerned;

(2)

information necessary for the preparation of NOTAM or ASHTAM;

(3)

information necessary for the preparation of aeronautical information circulars.

(d)

Meteorological information included in flight documentation shall be represented as follows:

(1)

winds on charts shall be depicted by arrows with feathers and shaded pennants on a sufficiently dense grid;

(2)

temperatures shall be depicted by figures on a sufficiently dense grid;

(3)

wind and temperature data selected from the data sets received from a world area forecast centre shall be depicted in a sufficiently dense latitude/longitude grid;

(4)

wind arrows shall take precedence over temperatures and chart background;

(5)

height indications referring to en-route meteorological conditions shall be expressed as determined to be appropriate for the situation, for instance in flight levels, pressure, altitude or height above ground level, whilst all references referring to aerodrome meteorological conditions shall be expressed in height above the aerodrome elevation.

(e)

Flight documentation shall comprise:

(1)

forecasts of upper-wind and upper-air temperature;

(2)

SIGWX phenomena;

(3)

METAR or, when issued, SPECI for the aerodromes of departure and intended landing, and for take-off, en-route and destination alternate aerodromes;

(4)

TAF or amended TAF for the aerodromes of departure and intended landing, and for take-off, en-route and destination alternate aerodromes;

(5)

[F1 SIGMET, and, when issued, AIRMET and appropriate special air-reports relevant to the whole route;]

(6)

volcanic ash and tropical cyclone advisory information relevant to the whole route.

However, when agreed between the aerodrome meteorological office and the operators concerned, flight documentation for flights of two hours' duration or less, after a short stop or turnaround, may be limited to the information operationally needed, but in all cases the flight documentation shall at least comprise the meteorological information listed in points (3), (4), (5) and (6).

(f)

Charts generated from digital forecasts shall be made available, as required by operators, for fixed areas of coverage as shown in Appendix 2.

(g)

[F1 When forecasts of upper-wind and upper-air temperature listed under point MET.OR.275(a)(1) are supplied in chart form, they shall be fixed-time prognostic charts for flight levels as specified in point MET.TR.275(b)(3). When forecasts of SIGWX phenomena listed under point MET.OR.275(a)(2) are supplied in chart form, they shall be fixed-time prognostic charts for an atmospheric layer limited by flight levels as specified in points MET.TR.275(c) and MET.TR.275(d).]

(h)

The forecasts of upper-wind and upper-air temperature and of SIGWX phenomena above flight level 100 shall be supplied as soon as they become available, but not later than 3 hours before departure.

(i)

Aeronautical climatological information shall be prepared in the form of aerodrome climatological tables and aerodrome climatological summaries.

MET.TR.220 Aerodrome forecasts U.K.

(a)

Aerodrome forecasts and amendments thereto shall be issued as a TAF and shall include, in the order indicated, the:

(1)

identification of the type of forecast;

(2)

location indicator;

(3)

time of issue of forecast;

(4)

identification of a missing forecast, when applicable;

(5)

date and period of validity of forecast;

(6)

identification of a cancelled forecast, when applicable;

(7)

surface wind;

(8)

visibility;

(9)

weather;

(10)

cloud;

(11)

expected significant changes to one or more of these elements during the period of validity.

(b)

TAF shall be issued in accordance with the template shown in Appendix 3 and disseminated in the TAF code form.

(c)

[F1 The period of validity of a routine TAF shall be either 9 or 24 or 30 hours, unless otherwise prescribed by the competent authority taking into account the traffic requirements for aerodromes with hours of operation of less than 9 hours. TAF shall be filed for transmission not earlier than 1 hour before the commencement of their period of validity.]

(d)

[F1 TAF, if disseminated in digital form, shall be:

(1)

formatted in accordance with a globally interoperable information exchange model and shall use geography markup language (GML);

(2)

accompanied by the appropriate metadata.]

(e)

The meteorological elements included in TAF shall be:

(1) Surface wind U.K.

(i)

In forecasting surface wind, the expected prevailing direction shall be given.

(ii)

When it is not possible to forecast a prevailing surface wind direction due to its expected variability, the forecasted wind direction shall be indicated as variable using ‘VRB’.

(iii)

When the wind is forecasted to be less than 1 kt (0,5 m/s), the forecasted wind speed shall be indicated as calm.

(iv)

When the forecasted maximum speed exceeds the forecasted mean wind speed by 10 kt (5 m/s) or more, the forecasted maximum wind speed shall be indicated.

(v)

When a wind speed of 100 kt (50 m/s) or more is forecasted, it shall be indicated to be more than 99 kt (49 m/s).

(2) Visibility U.K.

(i)

When the visibility is forecasted to be less than 800 m, it shall be expressed in steps of 50 m; when it is forecasted to be 800 m or more, but less than 5 km, in steps of 100 m; when it is forecasted to be 5 km or more, but less than 10 km, in kilometre steps; and when it is forecasted to be 10 km or more, it shall be expressed as 10 km, except when conditions of CAVOK are forecasted to apply. The prevailing visibility shall be forecasted.

(ii)

When visibility is forecasted to vary in different directions and the prevailing visibility cannot be forecasted, the lowest forecasted visibility shall be given.

(3) Weather phenomena U.K.

(i)

One or more, up to a maximum of three, of the following weather phenomena or combinations thereof, together with their characteristics and, where appropriate, intensity, shall be forecasted if they are expected to occur at the aerodrome:

(A)

freezing precipitation;

(B)

freezing fog;

(C)

moderate or heavy precipitation (including showers thereof);

(D)

low drifting dust, sand or snow;

(E)

blowing dust, sand or snow;

(F)

dust storm;

(G)

sandstorm;

(H)

thunderstorm (with or without precipitation);

(I)

squall;

(J)

funnel cloud (tornado or waterspout);

(K)

other weather phenomena, as agreed by the aerodrome meteorological office with the ATS units and operators concerned.

(ii)

The expected end of occurrence of those phenomena shall be indicated by the abbreviation ‘NSW’.

(4) Cloud U.K.

(i)

The cloud amount shall be forecast using the abbreviations ‘FEW’, ‘SCT’, ‘BKN’ or ‘OVC’, as necessary. When it is expected that the sky will remain or become obscured and clouds cannot be forecasted and information on vertical visibility is available at the aerodrome, the vertical visibility shall be forecasted in the form ‘VV’ followed by the forecasted value of the vertical visibility.

(ii)

When several layers or masses of cloud are forecasted, their amount and height of base shall be included in the following order:

(A)

the lowest layer or mass regardless of amount, to be forecasted as FEW, SCT, BKN or OVC as appropriate;

(B)

the next layer or mass covering more than 2/8, to be forecast as SCT, BKN or OVC as appropriate;

(C)

the next higher layer or mass covering more than 4/8, to be forecast as BKN or OVC as appropriate;

(D)

cumulonimbus clouds and/or towering cumulus clouds, whenever forecasted and not already included under points (A) to (C).

(iii)

Cloud information shall be limited to cloud of operational significance; when no cloud of operational significance is forecasted and ‘CAVOK’ is not appropriate, the abbreviation ‘NSC’ shall be used.

(f)

Use of change groups

(1)

The criteria used for the inclusion of change groups in TAF or for the amendment of TAF shall be based on any of the following weather phenomena, or combinations thereof, being forecasted to begin or end or change in intensity:

(i)

freezing fog;

(ii)

freezing precipitation;

(iii)

moderate or heavy precipitation (including showers thereof);

(iv)

thunderstorm;

(v)

dust storm;

(vi)

sandstorm.

(2)

When a change in any of the elements given in point (a) is required to be indicated, the change indicators ‘BECMG’ or ‘TEMPO’ shall be used followed by the time period during which the change is expected to occur. The time period shall be indicated as the beginning and end of the period in whole hours UTC. Only those elements for which a significant change is expected shall be included following a change indicator. However, in the case of significant changes in respect of cloud, all cloud groups, including layers or masses not expected to change, shall be indicated.

(3)

The change indicator ‘BECMG’ and the associated time group shall be used to describe changes where the meteorological conditions are expected to reach or pass through specified threshold values at a regular or irregular rate and at an unspecified time during the time period. The time period shall not exceed 4 hours.

(4)

The change indicator ‘TEMPO’ and the associated time group shall be used to describe expected frequent or infrequent temporary fluctuations in the meteorological conditions which reach or pass specified threshold values and last for a period of less than 1 hour in each instance and, in the aggregate, cover less than one half of the forecast period during which the fluctuations are expected to occur. If the temporary fluctuation is expected to last 1 hour or longer, the change group ‘BECMG’ shall be used in accordance with point (3), or the validity period should be subdivided in accordance with point (5).

(5)

Where one set of prevailing weather conditions is expected to change significantly and more or less completely to a different set of conditions, the period of validity shall be subdivided into self-contained periods using the abbreviation ‘FM’ followed immediately by a six-figure time group in days, hours and minutes UTC indicating the time the change is expected to occur. The subdivided period following the abbreviation ‘FM’ shall be self-contained and all forecasted conditions given before the abbreviation shall be superseded by those following the abbreviation.

(g)

The probability of occurrence of an alternative value of a forecast element or elements shall be included when:

(1)

[F1 a 30 % or 40 % probability of alternative meteorological conditions exists during a specific forecast time period; or

(2)

a 30 % or 40 % probability of temporary fluctuations in meteorological conditions exists during a specific forecast time period.]

This shall be indicated in the TAF by using the abbreviation ‘PROB’ followed by the probability in tens of per cent and, in the case referred to in point (1), the time period during which the values are expected to apply, or in the case referred to in point (2), by using the abbreviation ‘PROB’ followed by the probability in tens of per cent, the change indicator ‘TEMPO’ and associated time group.

MET.TR.225 Forecasts for landing U.K.

(a)

TREND forecasts shall be issued in accordance with Appendix 1.

(b)

The units and scales used in the TREND forecast shall be the same as those used in the report to which it is appended.

(c)

The TREND forecast shall indicate significant changes in respect of one or more of the elements: surface wind, visibility, weather phenomena and clouds. Only those elements for which a significant change is expected shall be included. However, in the case of significant changes in respect of cloud, all cloud groups, including layers or masses not expected to change, shall be indicated. In the case of a significant change in visibility, the phenomenon causing the reduction of visibility shall also be indicated. When no change is expected to occur, this shall be indicated by the term ‘NOSIG’.

(1) Surface wind U.K.

The TREND forecast shall indicate changes in the surface wind which involve:

(i)

a change in the mean wind direction of 60° or more, the mean speed before and/or after the change being 10 kt (5 m/s) or more;

(ii)

a change in mean wind speed of 10 kt (5 m/s) or more;

(iii)

changes in the wind through values of operational significance.

(2) Visibility U.K.

(i)

When the visibility is expected to improve and change to or pass through one or more of the following values, or when the visibility is expected to deteriorate and pass through one or more of the following values: 150, 350, 600, 800, 1 500 or 3 000 m, the trend forecast shall indicate the change.

(ii)

When significant numbers of flights are conducted in accordance with the visual flight rules, the forecast shall additionally indicate changes to or passing through 5 000 m.

(iii)

In TREND forecasts appended to METAR, visibility shall refer to the forecast prevailing visibility.

(3) Weather phenomena U.K.

(i)

The TREND forecast shall indicate the expected onset, cessation or change in intensity of any of the following weather phenomena or combinations thereof:

(A)

freezing precipitation;

(B)

moderate or heavy precipitation, including showers thereof;

(C)

thunderstorm, with precipitation;

(D)

dust storm;

(E)

sandstorm;

(F)

other weather phenomena as agreed by the aerodrome meteorological office with the ATS units and operators concerned.

(ii)

The TREND forecast shall indicate the expected onset or cessation of any of the following weather phenomena or combinations thereof:

(A)

freezing fog;

(B)

low drifting dust, sand or snow;

(C)

blowing dust, sand or snow;

(D)

thunderstorm (without precipitation);

(E)

squall;

(F)

funnel cloud (tornado or waterspout).

(iii)

The total number of phenomena reported in points (i) and (ii) shall not exceed three.

(iv)

The expected end of occurrence of the weather phenomena shall be indicated by the abbreviation ‘NSW’.

(4) Clouds U.K.

(i)

When the height of base of a cloud layer of BKN or OVC extent is expected to lift and change to or pass through one or more of the following values, or when the height of base of a cloud layer of BKN or OVC extent is expected to lower and pass through one or more of the following values: 100, 200, 500, 1 000 and 1 500 ft (30, 60, 150, 300 and 450 m), the TREND forecast shall indicate the change.

(ii)

When the height of base of a cloud layer is below or is expected to fall below or rise above 1 500 ft (450 m), the TREND forecast shall also indicate changes in cloud amount from FEW, or SCT increasing to BKN or OVC, or changes from BKN or OVC decreasing to FEW or SCT.

(iii)

When no clouds of operational significance are forecast and ‘CAVOK’ is not appropriate, the abbreviation ‘NSC’ shall be used.

(5) Vertical visibility U.K.

When the sky is expected to remain or become obscured and vertical visibility observations are available at the aerodrome, and the vertical visibility is forecast to improve and change to or pass through one or more of the following values, or when the vertical visibility is forecast to deteriorate and pass through one or more of the following values: 100, 200, 500 or 1 000 ft (30, 60, 150 or 300 m), the TREND forecast shall indicate the change.

(6) Additional criteria U.K.

The aerodrome meteorological office and the users may agree on additional criteria to be used, based on local aerodrome operating minima.

(7) Use of change groups U.K.

(i)

When a change is expected to occur, the TREND forecast shall begin with one of the change indicators ‘BECMG’ or ‘TEMPO’.

(ii)

The change indicator ‘BECMG’ shall be used to describe forecast changes where the meteorological conditions are expected to reach or pass through specified values at a regular or irregular rate. The period during which, or the time at which, the change is forecast to occur shall be indicated using the abbreviations ‘FM’, ‘TL’ or ‘AT’, as appropriate, each followed by a time group in hours and minutes.

(iii)

The change indicator ‘TEMPO’ shall be used to describe forecast temporary fluctuations in the meteorological conditions which reach or pass specified values and last for a period of less than 1 hour in each instance and, in the aggregate, cover less than one half of the period during which the fluctuations are forecast to occur. The period during which the temporary fluctuations are forecast to occur shall be indicated using the abbreviations ‘FM’ and/or ‘TL’, as appropriate, each followed by a time group in hours and minutes.

(8) Use of the probability indicator U.K.

The indicator ‘PROB’ shall not be used in TREND forecasts.

MET.TR.230 Forecasts for take-off U.K.

(a)

A forecast for take-off shall refer to a specified period of time and shall contain information on expected conditions over the runway complex in regard to surface wind direction and speed and any variations thereof, temperature, pressure, and any other elements as agreed between the aerodrome meteorological office and the operators.

(b)

The order of the elements and the terminology, units and scales used in forecasts for take-off shall be the same as those used in reports for the same aerodrome.

MET.TR.235 Aerodrome warnings and wind shear warnings and alerts U.K.

(a)

Wind shear warnings shall be issued in accordance with the template in Appendix 4.

(b)

The sequence number referred to in the template in Appendix 4 shall correspond to the number of wind shear warnings issued for the aerodrome since 00.01 UTC on the day concerned.

(c)

Wind shear alerts shall give concise, up-to-date information related to the observed existence of wind shear involving a headwind/tailwind change of 15 kt (7,5 m/s) or more which could adversely affect aircraft on the final approach path or initial take-off path and aircraft on the runway during the landing roll or take-off run.

(d)

Wind shear alert shall, if practicable, relate to specific sections of the runway and distances along the approach path or take-off path as agreed between the aerodrome meteorological office, the appropriate ATS units and the operators concerned.

Chapter 3 — Technical requirements for meteorological watch offices U.K.

[F1 MET.TR.250 SIGMET U.K.

(a)

The content and order of elements in a SIGMET shall be in accordance with the template shown in Appendix 5A.

(b)

SIGMET shall consist of three types:

(1)

SIGMET for en-route weather phenomena other than volcanic ash or tropical cyclones;

(2)

SIGMET for volcanic ash;

(3)

SIGMET for tropical cyclones.

(c)

The sequence number of SIGMET shall consist of three characters comprising one letter and two numbers.

(d)

Only one of the phenomena listed in Appendix 5A shall be included in a SIGMET, using the appropriate abbreviations and the following threshold value of surface wind speed of 34 kt (17 m/s) or more for tropical cyclone.

(e)

SIGMET concerning thunderstorms or a tropical cyclone shall not include references to associated turbulence and icing.

(f)

SIGMET, if disseminated in digital form, shall be:

(1)

formatted in accordance with a globally interoperable information exchange model and shall use geography markup language (GML);

(2)

accompanied by the appropriate metadata.

MET.TR.255 AIRMET U.K.

(a)

The content and order of elements in an AIRMET shall be in accordance with the template shown in Appendix 5A.

(b)

The sequence number referred to in the template in Appendix 5 shall correspond to the number of AIRMET issued for the flight information region since 00.01 UTC on the day concerned.

(c)

Only one of the phenomena in Appendix 5A shall be included in an AIRMET, using the appropriate abbreviations and the following threshold values, when the phenomenon is below flight level 100, or below flight level 150 in mountainous areas, or higher, where necessary:

(1)

widespread surface wind speed above 30 kt (15 m/s) with relevant direction and units;

(2)

widespread areas affected by reduction of visibility to less than 5 000 m, including the weather phenomenon causing the reduction of visibility;

(3)

widespread areas of broken or overcast cloud with height of base less than 1 000 ft (300 m) above ground level.

(d)

AIRMET concerning thunderstorms or cumulonimbus clouds shall not include references to associated turbulence and icing.

(e)

AIRMET, if disseminated in digital form, shall be:

(1)

formatted in accordance with a globally interoperable information exchange model and shall use geography markup language (GML);

(2)

accompanied by the appropriate metadata.]

MET.TR.260 Area forecasts for low-level flights U.K.

(a)

When chart form is used for area forecasts for low-level flights, the forecast of upper wind and upper-air temperature shall be issued for points separated by no more than 300 NM and for, as a minimum, the following altitudes: 2 000, 5 000 and 10 000 ft (600, 1 500 and 3 000 m) and 15 000 ft (4 500 m) in mountainous areas. The issuance of forecasts of upper wind and upper-air temperature at an altitude of 2 000 ft (600 m) may be subject to local orographic considerations as determined by the competent authority.

(b)

When chart form is used for area forecasts for low-level flights, the forecast of SIGWX phenomena shall be issued as low-level SIGWX forecast for flight levels up to 100, or up to flight level 150 in mountainous areas, or higher, where necessary. Low-level SIGWX forecasts shall include:

(1)

the following phenomena warranting the issuance of a SIGMET: icing, turbulence, cumulonimbus clouds that are obscured, frequent, embedded or occurring at a squall line, sandstorms/dust storms and volcanic eruptions or a release of radioactive materials into the atmosphere, and which are expected to affect low-level flights;

(2)

the following elements in area forecasts for low-level flights: surface wind, surface visibility, significant weather phenomena, mountain obscuration, cloud, icing, turbulence, mountain wave and height of zero-degree isotherm.

(c)

[F1 When the competent authority has determined that the density of traffic operating below flight level 100 warrants the issuance of an AIRMET, the area forecasts shall be issued to cover the layer between the ground and flight level 100, or up to flight level 150 in mountainous areas, or higher, where necessary, and shall contain information on en-route weather phenomena hazardous to low-level flights, in support of the issuance of the AIRMET and the additional information required for low-level flights.]

Chapter 4 — Technical requirements for volcanic ash advisory centres (VAAC) U.K.

[F1 MET.TR.265 Volcanic ash advisory centre responsibilities U.K.

(a)

The advisory information on volcanic ash shall be issued in abbreviated plain language and in accordance with the template shown in Appendix 6. When no abbreviations are available, English plain language text, to be kept to a minimum, shall be used.

(b)

Volcanic ash advisory, if disseminated in digital form, shall be:

(1)

formatted in accordance with a globally interoperable information exchange model and shall use geography markup language (GML);

(2)

accompanied by the appropriate metadata.

(c)

Volcanic ash advisory information, when prepared in graphical format, shall be issued using the portable network graphics (PNG) format.]

Chapter 5 — Technical requirements for tropical cyclone advisory centres (TCAC) U.K.

MET.TR.270 Tropical cyclone advisory centre responsibilities U.K.

(a)

The advisory information on tropical cyclones shall be issued for tropical cyclones when the maximum of the 10-minute mean surface wind speed is expected to reach or exceed 34 kt during the period covered by the advisory.

(b)

The advisory information on tropical cyclones shall be in accordance with Appendix 7.

(c)

[F2 Tropical cyclone advisory, if disseminated in digital form, shall be:

(1)

formatted in accordance with a globally interoperable information exchange model and shall use geography markup language (GML);

(2)

accompanied by the appropriate metadata.

(d)

Tropical cyclone advisory information, when prepared in graphical format, shall be issued using the portable network graphics (PNG) format.]

Chapter 6 — Technical requirements for world area forecast centres (WAFCs) U.K.

MET.TR.275 World area forecast centre responsibilities U.K.

(a)

WAFCs shall use processed meteorological data in the form of grid point values expressed in binary form (GRIB code form) for the supply of gridded global forecasts and BUFR code form for the supply of forecast of significant weather phenomena.

(b)

For global gridded forecasts, WAFCs shall:

(1)

prepare forecasts of:

(i)

upper wind;

(ii)

upper-air temperature;

(iii)

humidity;

(iv)

direction, speed and flight level of maximum wind;

(v)

flight level and temperature of tropopause;

(vi)

areas of cumulonimbus clouds;

(vii)

icing;

(viii)

clear-air and in-cloud turbulence;

(ix)

geopotential altitude of flight levels;

four times a day and be valid for fixed valid times at 6, 9, 12, 15, 18, 21, 24, 27, 30, 33 and 36 hours after the time (00.00, 06.00, 12.00 and 18.00 UTC) of the synoptic data on which the forecasts were based;

(2)

issue forecasts in the order referred to in point (1) and complete their dissemination as soon as technically feasible, but not later than 6 hours after standard time of observation;

(3)

provide grid point forecasts in a regular grid with a horizontal resolution of 1,25° of latitude and longitude and comprising:

(i)

[F1 wind data for flight levels 50 (850 hPa), 80 (750 hPa), 100 (700 hPa), 140 (600 hPa), 180 (500 hPa), 210 (450 hPa), 240 (400 hPa), 270 (350 hPa), 300 (300 hPa), 320 (275 hPa), 340 (250 hPa), 360 (225 hPa), 390 (200 hPa), 410 (175 hPa), 450 (150 hPa), 480 (125 hPa) and 530 (100 hPa);

(ii)

temperature data for flight levels 50 (850 hPa), 80 (750 hPa), 100 (700 hPa), 140 (600 hPa), 180 (500 hPa), 210 (450 hPa), 240 (400 hPa), 270 (350 hPa), 300 (300 hPa), 320 (275 hPa), 340 (250 hPa), 360 (225 hPa), 390 (200 hPa), 410 (175 hPa), 450 (150 hPa) 480 (125 hPa) and 530 (100 hPa);

(iii)

humidity data for flight levels 50 (850 hPa), 80 (750 hPa), 100 (700 hPa), 140 (600 hPa) and 180 (500 hPa);]

(iv)

horizontal extent and flight levels of base and top of cumulonimbus clouds;

(v)

icing for layers centred at flight levels 60 (800 hPa), 100 (700 hPa), 140 (600 hPa), 180 (500 hPa), 240 (400 hPa) and 300 (300 hPa);

(vi)

clear-air turbulence for layers centred at flight levels 240 (400 hPa), 270 (350 hPa), 300 (300 hPa), 340 (250 hPa), 390 (200 hPa) and 450 (150 hPa);

(vii)

in-cloud turbulence for layers centred at flight levels 100 (700 hPa), 140 (600 hPa), 180 (500 hPa), 240 (400 hPa) and 300 (300 hPa);

(viii)

[F1 geopotential altitude data for flight levels 50 (850 hPa), 80 (750 hPa), 100 (700 hPa), 140 (600 hPa), 180 (500 hPa), 210 (450 hPa), 240 (400 hPa), 270 (350 hPa), 300 (300 hPa), 320 (275 hPa), 340 (250 hPa), 360 (225 hPa), 390 (200 hPa), 410 (175 hPa), 450 (150 hPa) 480 (125 hPa) and 530 (100 hPa).]

(c)

For global forecasts of en-route significant weather phenomena, WAFCs shall:

(1)

prepare SIGWX forecasts four times a day and shall be valid for fixed valid times at 24 hours after the time (00.00, 06.00, 12.00 and 18.00 UTC) of the synoptic data on which the forecasts were based. The dissemination of each forecast shall be completed as soon as technically feasible, but not later than 9 hours after standard time of observation;

(2)

issue SIGWX forecasts as high-level SIGWX forecasts for flight levels between 250 and 630;

(3)

include in SIGWX forecasts the following items:

(i)

tropical cyclone provided that the maximum of the 10-minute mean surface wind speed is expected to reach or exceed 34 kt (17 m/s);

(ii)

severe squall lines;

(iii)

moderate or severe turbulence (in cloud or clear air);

(iv)

moderate or severe icing;

(v)

widespread sandstorm/dust storm;

(vi)

cumulonimbus clouds associated with thunderstorms and with points (i) to (v);

(vii)

non-convective cloud areas associated with in-cloud moderate or severe turbulence and/or moderate or severe icing;

(viii)

flight level of tropopause;

(ix)

jet streams;

(x)

information on the location of volcanic eruptions that are producing ash clouds of significance to aircraft operations, comprising: volcanic eruption symbol at the location of the volcano and, in a separate text box on the chart, the volcanic eruption symbol, the name of the volcano, if known, and the latitude/longitude of the eruption. In addition, the legend of SIGWX charts should indicate ‘CHECK SIGMET, ADVISORIES FOR TC AND VA, AND ASHTAM AND NOTAM FOR VA’;

(xi)

information on the location of a release of radioactive materials into the atmosphere of significance to aircraft operations, comprising: the radioactive materials in the atmosphere symbol at the location of the release and, in a separate box on the chart, the radioactive materials in the atmosphere symbol, latitude/longitude of the site of the release and, if known, the name of the site of the radioactive source. In addition, the legend of SIGWX charts on which a release of radiation is indicated should contain ‘CHECK SIGMET AND NOTAM FOR RDOACT CLD’.

(4)

The following criteria shall be applied for SIGWX forecasts:

(i)

points (i) to (vi) of point (3) shall only be included if expected to occur between the lower and upper levels of the SIGWX forecast;

(ii)

the abbreviation ‘CB’ shall only be included when it refers to the occurrence or expected occurrence of cumulonimbus clouds:

(A)

affecting an area with a maximum spatial coverage of 50 % or more of the area concerned;

(B)

along a line with little or no space between individual clouds; or

(C)

embedded in cloud layers or concealed by haze;

(iii)

the inclusion of ‘CB’ shall be understood to include all weather phenomena normally associated with cumulonimbus clouds, i.e. thunderstorm, moderate or severe icing, moderate or severe turbulence, and hail;

(iv)

where a volcanic eruption or a release of radioactive materials into the atmosphere warrants the inclusion of the volcanic activity symbol or the radioactivity symbol in SIGWX forecasts, the symbols shall be included on SIGWX forecasts irrespective of the height to which the ash column or radioactive material is reported or expected to reach;

(v)

in the case of coincident or the partial overlapping of points (i), (x) and (xi) of point (3), the highest priority shall be given to point (x), followed by points (xi) and (i). The point with the highest priority shall be placed at the location of the event, and an arrow shall be used to link the location of the other point(s) to its (their) associated symbol(s) or text box(es).

(d)

Medium-level SIGWX forecasts for flight levels between 100 and 250 for limited geographical areas shall be issued.

Appendix 1

a To be included if visibility or runway visual range < 1 500 m; for up to a maximum of four runways.
b Heavy used to indicate tornado or waterspout; moderate (no qualifier) to indicate funnel cloud not reaching the ground.
Template for METAR Key: M = inclusion mandatory, part of every message; C = inclusion conditional, dependent on meteorological conditions or method of observation; O = inclusion optional. Note 1: The ranges and resolutions for the numerical elements included in METAR are shown below this template. Note 2: The explanations for the abbreviations can be found in Procedures for Air Navigation Services — ICAO Abbreviations and Codes (PANS-ABC, Doc 8400).
Element	Detailed content		Template(s)					Examples
Identification of the type of report (M)	Type of report (M)		METAR, METAR COR,					METAR METAR COR
Location indicator (M)	ICAO location indicator (M)		Nnnn					YUDO
Time of the observation (M)	Day and actual time of the observation in UTC (M)		nnnnnnZ					221630Z
Identification of an automated or missing report (C)	Automated or missing report identifier (C)		AUTO or NIL					AUTO NIL
END OF METAR IF THE REPORT IS MISSING.
Surface wind (M)	Wind direction (M)		Nnn		VRB			24004MPS (24008KT) VRB01MPS (VRB02KT) 19006MPS (19012KT) 00000MPS (00000KT) 140P149MPS (140P99KT)
	Wind speed (M)		[P]nn[n]
	Significant speed variations (C)		G[P]nn[n]					12003G09MPS (12006G18KT) 24008G14MPS (24016G28KT)
	Units of measurement (M)		MPS (or KT)
	Significant directional variations (C)		nnnVnnn		—			02005MPS 350V070 (02010KT 350V070)
Visibility (M)	Prevailing or minimum visibility (M)		Nnnn			CAVOK		0350 CAVOK 7000 9999 0800
	Minimum visibility and direction of the minimum visibility (C)		nnnn[N] or nnnn[NE] or nnnn[E] or nnnn[SE] or nnnn[S] or nnnn[SW] or nnnn[W] or nnnn[NW]					2000 1200NW 6000 2800E 6000 2800
Runway visual range (C)a	Name of the element (M)		R					R32/0400 R12R/1700 R10/M0050 R14L/P2000
	Runway (M)		nn[L]/or nn[C]/or nn[R]/
	Runway visual range (M)		[P or M]nnnn					R16L/0650 R16C/0500 R16R/0450 R17L/0450
	Runway visual range past tendency (C)		U, D or N					R12/1100U R26/0550N R20/0800D R12/0700
Present weather (C)	Intensity or proximity of present weather (C)		– or +	—	VC
	Characteristics and type of present weather (M)		DZ or RA or SN or SG or PL or DS or SS or FZDZ or FZRA or FZUP or FCb or SHGR or SHGS or SHRA or SHSN or SHUP or TSGR or TSGS or TSRA or TSSN or TSUP or UP	FG or BR or SA or DU or HZ or FU or VA or SQ or PO or TS or BCFG or BLDU or BLSA or BLSN or DRDU or DRSA or DRSN or FZFG or MIFG or PRFG or //	FG or PO or FC or DS or SS or TS or SH or BLSN or BLSA or BLDU or VA			RA HZ VCFG +TSRA FG VCSH +DZ VA VCTS –SN MIFG VCBLSA +TSRASN –SNRA DZ FG +SHSN BLSN UP FZUP TSUP FZUP //
Cloud (M)	Cloud amount and height of cloud base or vertical visibility (M)		FEWnnn or SCTnnn or BKNnnn or OVCnnn or FEW/// or SCT/// or BKN/// or OVC/// or ///nnn or //////	VVnnn or VV///	NSC or NCD			FEW015 VV005 OVC030 VV/// NSC SCT010 OVC020 BKN/// ///015
	Cloud type (C)		CB or TCU or ///	—				BKN009TCU NCD SCT008 BKN025CB BKN025/// //////CB
Air and dew-point temperature (M)	Air and dew-point temperature (M)		[M]nn/[M]nn					17/10 02/M08 M01/M10
Pressure values (M)	Name of the element (M)		Q					Q0995 Q1009 Q1022 Q0987
	QNH (M)		Nnnn
Supplementary information (C)	Recent weather (C)		REFZDZ or REFZRA or REDZ or RE[SH]RA or RERASN or RE[SH]SN or RESG or RESHGR or RESHGS or REBLSN or RESS or REDS or RETSRA or RETSSN or RETSGR or RETSGS or RETS or REFC or REVA or REPL or REUP or REFZUP or RETSUP or RESHUP					REFZRA RETSRA
	Wind shear (C)		WS Rnn[L] or WS Rnn[C] or WS Rnn[R] or WS ALL RWY					WS R03 WS ALL RWY WS R18C
	Sea–surface temperature and state of the sea or significant wave height (C)		W[M]nn/Sn or W[M]nn/Hn[n][n]					W15/S2 W12/H75
	State of the runway (C)	Runway designator (M)	R nn[L]/ or Rnn[C]/ or Rnn[R]/			R/SNOCLO		R99/421594 R/SNOCLO R14L/CLRD//
		Runway deposits (M)	n or /		CLRD//
		Extent of runway contamination (M)	n or /
		Depth of deposit (M)	nn or //
		Friction coefficient or braking action (M)	nn or //
Trend forecast (O)	Change indicator (M)		NOSIG	BECMG or TEMPO				NOSIG BECMG FEW020 TEMPO 25018G25MPS (TEMPO 25036G50KT) BECMG FM1030 TL1130 CAVOK BECMG TL1700 0800 FG BECMG AT1800 9000 NSW BECMG FM1900 0500 +SNRA BECMG FM1100 SN TEMPO FM1130 BLSN TEMPO FM0330 TL0430 FZRA
	Period of change (C)			FMnnnn and/or TLnnnn or ATnnnn
	Wind (C)			nnn[P]nn[n][G[P]nn[n]]MPS (or nnn[P]nn[G[P]nn]KT)
	Prevailing visibility (C)			nnnn			CAVOK
	Weather phenomenon: intensity (C)			– or +	—	NSW
	Weather phenomenon: characteristics and type (C)			DZ or RA or SN or SG or PL or DS or SS or FZDZ or FZRA or SHGR or SHGS or SHRA or SHSN or TSGR or TSGS or TSRA or TSSN	FG or BR or SA or DU or HZ or FU or VA or SQ or PO or FC or TS or BCFG or BLDU or BLSA or BLSN or DRDU or DRSA or DRSN or FZFG or MIFG or PRFG
	Cloud amount and height of cloud base or vertical visibility (C)			FEWnnn or SCTnnn or BKNnnn or OVCnnn	VVnnn or VV///	NSC		TEMPO TL1200 0600 BECMG AT1200 8000 NSW NSC BECMG AT1130 OVC010
	Cloud type (C)			CB or TCU	—			TEMPO TL1530 +SHRA BKN012CB

* There is no aeronautical requirement to report surface wind speeds of 100 kt (50 m/s) or more; however, provision has been made for reporting wind speeds up to 199 kt (99 m/s) for non-aeronautical purposes, as necessary.
Ranges and resolutions for the numerical elements included in METAR
	Element		Range	Resolution
Runway:	(no units)		01–36	1
Wind direction:		°true	000–360	10
Wind speed:		MPS	00–99	1
		KT	00–199	1
Visibility:		M	0000–0750	50
		M	0800–4 900	100
		M	5 000–9 000	1 000
		M	10 000–	0 (fixed value: 9 999)
Runway visual range:		M	0000–0375	25
		M	0400–0750	50
		M	0800–2 000	100
Vertical visibility:	30's M (100's FT)		000–020	1
Clouds: height of cloud base:	30's M (100's FT)		000–100	1
Air temperature;			– 80 - +60	1
Dew-point temperature:		°C
QNH:		hPa	0850–1 100	1
Sea–surface temperature:		°C	– 10 - +40	1
State of the sea:		(no units)	0–9	1
Significant wave height		M	0–999	0,1
State of the runway	Runway designator:	(no units)	01–36; 88; 99	1
	Runway deposits:	(no units)	0–9	1
	Extent of runway contamination:	(no units)	1; 2; 5; 9	—
	Depth of deposit:	(no units)	00–90; 92–99	1
	Friction coefficient/braking action:	(no units)	00–95; 99	1

Appendix 2

Fixed areas of coverage of WAFS forecasts in chart form U.K.

Mercator projection U.K.

Polar stereographic projection (northern hemisphere) U.K.

Polar stereographic projection (southern hemisphere) U.K.

[F1 Appendix 3

Template for TAF U.K.

Key:

M

=

inclusion mandatory;

C

=

inclusion conditional, dependent on meteorological conditions or method of observation;

O

=

inclusion optional.

Note 1: the ranges and resolutions for the numerical elements included in TAF are provided in a separate table below this template. U.K.

Note 2: the explanations for the abbreviations can be found in ICAO Doc 8400 ‘ Procedures for Air Navigation Services – Abbreviations and Codes (PANS-ABC) ’ . U.K.

a To be included whenever applicable. No qualifier for moderate intensity.
b Up to four cloud layers.
c Consisting of up to a maximum of four temperatures (two maximum temperatures and two minimum temperatures).
Element	Detailed content	Template(s)				Examples
Identification of the type of forecast (M)	Type of forecast (M)	TAF or TAF AMD or TAF COR				TAF TAF AMD TAF COR
Location indicator (M)	ICAO location indicator (M)	nnnn				YUDO
Time of issue of forecast (M)	Day and time of issue of the forecast in UTC (M)	nnnnnnZ				160000Z
Identification of a missing forecast (C)	Missing forecast identifier (C)	NIL				NIL
END OF TAF IF THE FORECAST IS MISSING
Days and period of validity of forecast (M)	Days and period of validity of the forecast in UTC (M)	nnnn/nnnn				0812/0918
Identification of a cancelled forecast (C)	Cancelled forecast identifier (C)	CNL				CNL
END OF TAF IF THE FORECAST IS CANCELLED
Surface wind (M)	Wind direction (M)	nnn or VRB				24004MPS; VRB01MPS (24008KT); (VRB02KT) 19005MPS (19010KT)
	Wind speed (M)	[P]nn[n]				00000MPS (00000KT) 140P49MPS (140P99KT)
	Significant speed variations (C)	G[P]nn[n]				12003G09MPS (12006G18KT) 24008G14MPS (24016G28KT)
	Units of measurement (M)	MPS (or KT)
Visibility (M)	Prevailing visibility (M)	nnnn			C A V O K	0350 CAVOK 7000 9000 9999
Weather (C)	Intensity of weather phenomena (C) a	– or +		—
	Characteristics and type of weather phenomena (C)	DZ or RA or SN or SG or PL or DS or SS or FZDZ or FZRA or SHGR or SHGS or SHRA or SHSN or TSGR or TSGS or TSRA or TSSN		FG or BR or SA or DU or HZ or FU or VA or SQ or PO or FC or TS or BCFG or BLDU or BLSA or BLSN or DRDU or DRSA or DRSN or FZFG or MIFG or PRFG		RA HZ +TSRA FG –FZDZ PRFG +TSRASN SNRA FG
Cloud (M) b	Cloud amount and height of base or vertical visibility (M)	FEWnnn or SCTnnn or BKNnnn or OVCnnn	VVnnn or VV///	NSC		FEW010 VV005 OVC020 VV/// NSC SCT005 BKN012
	Cloud type (C)	CB or TCU	—			SCT008 BKN025CB
Temperature (O) c	Name of the element (M)	TX				TX25/1013Z TN09/1005Z TX05/2112Z TNM02/2103Z
	Maximum temperature (M)	[M]nn/
	Day and time of occurrence of the maximum temperature (M)	nnnnZ
	Name of the element (M)	TN
	Minimum temperature (M)	[M]nn/
	Day and time of occurrence of the minimum temperature (M)	nnnnZ
Expected significant changes to one or more of the above elements during the period of validity (C)	Change or probability indicator (M)	PROB30 [TEMPO] or PROB40 [TEMPO] or BECMG or TEMPO or FM
	Period of occurrence or change (M)	nnnn/nnnn or nnnnnn
	Wind (C)	nnn[P]nn[n][G[P]nn[n]]MPS or VRBnnMPS (or nnn[P]nn[G[P]nn]KT or VRBnnKT)				TEMPO 0815/0818 25017G25MPS (TEMPO 0815/0818 25034G50KT) TEMPO 2212/2214 17006G13MPS 1000 TSRA SCT010CB BKN020 (TEMPO 2212/2214 17012G26KT 1000 TSRA SCT010CB BKN020)
	Prevailing visibility (C)	nnnn			C A V O K	BECMG 3010/3011 00000MPS 2400 OVC010 (BECMG 3010/3011 00000KT 2400 OVC010) PROB30 1412/1414 0800 FG
	Weather phenomenon: intensity (C)	– or +	—	NSW		BECMG 1412/1414 RA TEMPO 2503/2504 FZRA TEMPO 0612/0615 BLSN PROB40 TEMPO 2923/3001 0500 FG
	Weather phenomenon: characteristics and type (C)	DZ or RA or SN or SG or PL or DS or SS or FZDZ or FZRA or SHGR or SHGS or SHRA or SHSN or TSGR or TSGS or TSRA or TSSN	FG or BR or SA or DU or HZ or FU or VA or SQ or PO or FC or TS or BCFG or BLDU or BLSA or BLSN or DRDU or DRSA or DRSN or FZFG or MIFG or PRFG
	Cloud amount and height of base or vertical visibility (C)	FEWnnn or SCTnnn or BKNnnn or OVCnnn	VVnnn or VV///	NSC		FM051230 15004MPS 9999 BKN020 (FM051230 15008KT 9999 BKN020) BECMG 1618/1620 8000 NSW NSC
	Cloud type (C)	CB or TCU	—			BECMG 2306/2308 SCT015CB BKN020

Ranges and resolutions for the numerical elements included in TAF U.K.

a There is no aeronautical requirement to report surface wind speeds of 100 kt (50 m/s) or more; however, provision has been made for reporting wind speeds up to 199 kt (99 m/s) for non-aeronautical purposes, as necessary.
Elements		Range	Resolution
Wind direction:	° true	000–360	10
Wind speed:	MPS	00–99 a	1
	KT	0–199 a	1
Visibility:	M	0000–0750	50
	M	0800–4 900	100
	M	5 000–9 000	1 000
	M	10 000 –	0 (fixed value: 9 999 )
Vertical visibility:	30’s M (100’s FT)	000–020	1
Cloud: height of cloud base:	30’s M (100’s FT)	000–099 100–200	1 10
Air temperature (maximum and minimum): °C		–80 – +60	1

Appendix 4 Template for wind shear warnings

Key:

M

=

inclusion mandatory;

C

=

inclusion conditional, whenever applicable.

Note 1: the ranges and resolutions for the numerical elements included in wind shear warnings are shown in Appendix 8. U.K.

Note 2: the explanations for the abbreviations can be found in ICAO Doc 8400 ‘ Procedures for Air Navigation Services – Abbreviations and Codes (PANS-ABC) ’ U.K.

Element	Detailed content	Template(s)	Example
Location indicator of the aerodrome (M)	Location indicator of the aerodrome	nnnn	YUCC
Identification of the type of message (M)	Type of message and sequence number	WS WRNG [n]n	WS WRNG 1
Time of origin and validity period (M)	Day and time of issue and, where applicable, validity period in UTC	nnnnnn [VALID TL nnnnnn] or [VALID nnnnnn/nnnnnn]	211230 VALID TL 211330 221200 VALID 221215/221315
IF THE WIND SHEAR WARNING IS TO BE CANCELLED, SEE DETAILS AT THE END OF THE TEMPLATE
Phenomenon (M)	Identification of the phenomenon and its location	[MOD] or [SEV] WS IN APCH or [MOD] or [SEV] WS [APCH] RWYnnn or [MOD] or [SEV] WS IN CLIMB-OUT or [MOD] or [SEV] WS CLIMB-OUT RWYnnn or MBST IN APCH or MBST [APCH] RWYnnn or MBST IN CLIMB-OUT or MBST CLIMB-OUT RWYnnn	WS APCH RWY12 MOD WS RWY34 WS IN CLIMB-OUT MBST APCH RWY26 MBST IN CLIMB-OUT
Observed, reported or forecast phenomenon (M)	Identification whether the phenomenon is observed or reported and expected to continue, or forecast	REP AT nnnn nnnnnnnn or OBS [AT nnnn] or FCST	REP AT 1510 B747 OBS AT 1205 FCST
Details of the phenomenon (C)	Description of phenomenon causing the issuance of the wind shear warning	SFC WIND: nnn/nnMPS (or nnn/nnKT) nnnM (nnnFT)-WIND: nnn/nnMPS (or nnn/nnKT) or nnKMH (or nnKT) LOSS nnKM (or nnNM) FNA RWYnn or nnKMH (or nnKT) GAIN nnKM (or nnNM) FNA RWYnn	SFC WIND: 320/5MPS 60M-WIND: 360/13MPS (SFC WIND: 320/10KT 200FT-WIND: 360/26KT) 60KMH LOSS 4KM FNA RWY13 (30KT LOSS 2NM FNA RWY13)
OR
Cancellation of wind shear warning	Cancellation of wind shear warning referring to its identification	CNL WS WRNG [n]n nnnnnn/nnnnnn	CNL WS WRNG 1 211230/211330]

F3 Appendix 5

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Textual Amendments

F3 Deleted by Commission Implementing Regulation (EU) 2020/469 of 14 February 2020 amending Regulation (EU) No 923/2012, Regulation (EU) No 139/2014 and Regulation (EU) 2017/373 as regards requirements for air traffic management/air navigation services, design of airspace structures and data quality, runway safety and repealing Regulation (EC) No 73/2010 (Text with EEA relevance).

[F2 Appendix 5A Template for SIGMET and AIRMET

Key:

M

=

inclusion mandatory;

C

=

inclusion conditional, whenever applicable; and

=

=

a double line indicates that the text following it shall be placed on the subsequent line.

Note: the ranges and resolutions for the numerical elements included in SIGMET/AIRMET are shown in Appendix 8. U.K.

a Only for SIGMET for tropical cyclones.
b Only for SIGMET for volcanic ash.
c To be used for two volcanic ash clouds or two centres of tropical cyclones simultaneously affecting the FIR concerned.
d The number of coordinates shall be kept to a minimum and shall not normally exceed seven.
e The elements ‘ forecast time ’ and ‘ forecast position ’ are not to be used in conjunction with the element ‘ movement or expected movement ’ .
Note: severe or moderate icing and severe or moderate turbulence (SEV ICE, MOD ICE, SEV TURB, MOD TURB) associated with thunderstorms, cumulonimbus clouds or tropical cyclones shall not be included.
Element	Detailed content	SIGMET template		AIRMET template	SIGMET Examples	AIRMET Examples
Location indicator of FIR/CTA (M)	ICAO location indicator of the ATS unit serving the FIR or CTA to which the SIGMET/AIRMET refers	nnnn			YUCC YUDD
Identification (M)	SIGMET or AIRMET identification and sequence number	SIGMET nnn		AIRMET [n][n]n	SIGMET U05 SIGMET I12	AIRMET 2 AIRMET 19 AIRMET B19
Validity period (M)	Day-time groups indicating the period of validity in UTC	VALID nnnnnn/nnnnnn			VALID 010000/010400 VALID 221215/221600 VALID 101520/101800 VALID 251600/252200 VALID 152000/160000 VALID 192300/200300
Location indicator of MWO (M)	Location indicator of MWO originating the SIGMET or AIRMET with a separating hyphen	nnnn–			YUDO– YUSO–
Name of the FIR/CTA (M)	Location indicator and name of the FIR/CTA for which the SIGMET/AIRMET is issued	nnnn nnnnnnnnnn FIR[/UIR] or nnnn nnnnnnnnnn CTA	nnnn nnnnnnnnnn FIR[/n]		YUCC AMSWELL FIR YUDD SHANLON FIR/UIR YUDD SHANLON CTA	YUCC AMSWELL FIR/2 YUDD SHANLON FIR
IF THE SIGMET IS TO BE CANCELLED, SEE DETAILS AT THE END OF THE TEMPLATE
Phenomenon (M)	Description of the phenomenon causing the issuance of SIGMET/AIRMET	OBSC TS[GR] EMBD TS[GR] FRQ TS[GR] SQL TS[GR]		SFC WIND nnn/nn[n]MPS (or SFC WIND nnn/nn[n]KT)	OBSC TS OBSC TSGR EMBD TS EMBD TSGR FRQ TS FRQ TSGR SQL TS SQL TSGR TC GLORIA PSN N10 W060 CB TC NN PSN S2030 E06030 CB SEV TURB SEV ICE SEV ICE (FZRA) SEV MTW HVY DS HVY SS VA ERUPTION MT ASHVAL PSN S15 E073 VA CLD RDOACT CLD	SFC WIND 040/40MPS SFC WIND 310/20KT SFC VIS 1500M (BR) ISOL TS ISOL TSGR OCNL TS OCNL TSGR MT OBSC BKN CLD 120/900M BKN CLD 400/3000FT BKN CLD SFC/3000M BKN CLD SFC/ABV10000FT OVC CLD 270/ABV3000M OVC CLD 900/ABV10000FT OVC CLD SFC/3000M OVC CLD SFC/ABV10000FT ISOL CB OCNL CB FRQ CB ISOL TCU OCNL TCU FRQ TCU MOD TURB MOD ICE MOD MTW
		TC nnnnnnnnnn PSN Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] CB or TC NN PSN Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] CB SEV TURB SEV ICE SEV ICE (FZRA) SEV MTW HVY DS HVY SS [VA ERUPTION] [MT nnnnnnnnnn] [PSN Nnn[nn] or Snn[nn] Ennn[nn] or Wnnn[nn]] VA CLD RDOACT CLD		SFC VIS nnnnM (nn) ISOL TS[GR] OCNL TS[GR] MT OBSC BKN CLD nnn/[ABV]nnnnM (or BKN CLD nnn/[ABV][n]nnnnFT) or BKN CLD SFC/[ABV]nnnnM (or BKN CLD SFC/[ABV][n]nnnnFT) OVC CLD nnn/[ABV]nnnnM (or OVC CLD nnn/[ABV][n]nnnnFT) or OVC CLD SFC/[ABV]nnnnM (or OVC CLD SFC/[ABV][n]nnnnFT) ISOL CB OCNL CB FRQ CB ISOL TCU OCNL TCU FRQ TCU MOD TURB MOD ICE MOD MTW
Observed or forecast phenomenon (M)	Indication whether the information is observed and expected to continue, or forecast	OBS [AT nnnnZ] or FCST [AT nnnnZ]			OBS OBS AT 1210Z FCST FCST AT 1815Z
Location (C)	Location (referring to latitude and longitude (in degrees and minutes))	Nnn[nn] Wnnn[nn] or Nnn[nn] Ennn[nn] or Snn[nn] Wnnn[nn] or Snn[nn] Ennn[nn] or N OF Nnn[nn] or S OF Nnn[nn] or N OF Snn[nn] or S OF Snn[nn] or [AND] W OF Wnnn[nn] or E OF Wnnn[nn] or W OF Ennn[nn] or E OF Ennn[nn] or N OF Nnn[nn] or N OF Snn[nn] AND S OF Nnn[nn] or S OF Snn[nn] or W OF Wnnn[nn] or W OF Ennn[nn] AND E OF Wnnn[nn] or E OF Ennn[nn] or N OF LINE or NE OF LINE or E OF LINE or SE OF LINE or S OF LINE or SW OF LINE or W OF LINE or NW OF LINE Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] [– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]] [– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]] [AND N OF LINE or NE OF LINE or E OF LINE or SE OF LINE or S OF LINE or SW OF LINE or W OF LINE or NW OF LINE Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] [– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]] [– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]]] or WI Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – [Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]] d or APRX nnKM WID LINE BTN (or nnNM WID LINE BTN) Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] [– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]][– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]] or ENTIRE FIR/UIR or ENTIRE CTA or WI nnnKM (or nnnNM) OF TC CENTRE			N2020 W07005 N48 E010 S60 W160 S0530 E16530 N OF N50 S OF N5430 N OF S10 S OF S4530 W OF W155 E OF W45 W OF E15540 E OF E09015 N OF N1515 AND W OF E13530 S OF N45 AND N OF N40 N OF LINE S2520 W11510 – S2520 W12010 SW OF LINE N50 W005 – N60 W020 SW OF LINE N50 W020 – N45 E010 AND NE OF LINE N45 W020 – N40 E010 WI N6030 E02550 – N6055 E02500 – N6050 E02630 – N6030 E02550 APRX 50KM WID LINE BTN N64 W017 – N60 W010 – N57 E010 ENTIRE FIR ENTIRE FIR/UIR ENTIRE CTA WI 400KM OF TC CENTRE WI 250NM OF TC CENTRE
Level (C)	Flight level or altitude	[SFC/]FLnnn or [SFC/]nnnnM (or [SFC/][n]nnnnFT) or FLnnn/nnn or TOP FLnnn or [TOP] ABV FLnnn or [nnnn/]nnnnM (or [[n]nnnn/][n]nnnnFT) or [nnnnM/]FLnnn (or [[n]nnnnFT/]FLnnn) or a TOP [ABV or BLW] FLnnn			FL180 SFC/FL070 SFC/3000M SFC/10000FT FL050/080 TOP FL390 ABV FL250 TOP ABV FL100 3000M 2000/3000M 8000FT 6000/12000FT 2000M/FL150 10000FT/FL250 TOP FL500 TOP ABV FL500 TOP BLW FL450
Movement or expected movement (C) e	Movement or expected movement (direction and speed) with reference to one of the 16 points of compass, or stationary	MOV N [nnKMH] or MOV NNE [nnKMH] or MOV NE [nnKMH] or MOV ENE [nnKMH] or MOV E [nnKMH] or MOV ESE [nnKMH] or MOV SE [nnKMH] or MOV SSE [nnKMH] or MOV S [nnKMH] or MOV SSW [nnKMH] or MOV SW [nnKMH] or MOV WSW [nnKMH] or MOV W [nnKMH] or MOV WNW [nnKMH] or MOV NW [nnKMH] or MOV NNW [nnKMH] (or MOV N [nnKT] or MOV NNE [nnKT] or MOV NE [nnKT] or MOV ENE [nnKT] or MOV E [nnKT] or MOV ESE [nnKT] or MOV SE [nnKT] or MOV SSE [nnKT] or MOV S [nnKT] or MOV SSW [nnKT] or MOV SW [nnKT] or MOV WSW [nnKT] or MOV W [nnKT] or MOV WNW [nnKT] or MOV NW [nnKT] or MOV NNW [nnKT]) or STNR			MOV SE MOV NNW MOV E 40KMH MOV E 20KT MOV WSW 20KT STNR
Changes in intensity (C)	Expected changes in intensity	INTSF or WKN or NC			INTSF WKN NC
Forecast time (C) e	Indication of the forecast time of phenomenon	FCST AT nnnnZ		—	FCST AT 2200Z	—
Forecast position (C) e	Forecast position of volcanic ash cloud or the centre of the tropical cyclone or other hazardous phenomena6 at the end of the validity period of the SIGMET	Nnn[nn] Wnnn[nn] or Nnn[nn] Ennn[nn] or Snn[nn] Wnnn[nn] or Snn[nn] Ennn[nn] or N OF Nnn[nn] or S OF Nnn[nn] or N OF Snn[nn] or S OF Snn[nn] [AND] W OF Wnnn[nn] or E OF Wnnn[nn] or W OF Ennn[nn] or E OF Ennn[nn] or N OF Nnn[nn] or N OF Snn[nn] AND S OF Nnn[nn] or S OF Snn[nn] or W OF Wnnn[nn] or W OF Ennn[nn] AND E OF Wnnn[nn] or E OF Ennn[nn] or N OF LINE or NE OF LINE or E OF LINE or SE OF LINE or S OF LINE or SW OF LINE or W OF LINE or NW OF LINE Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] [– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]] [AND N OF LINE or NE OF LINE or E OF LINE or SE OF LINE or S OF LINE or SW OF LINE or W OF LINE or NW OF LINE Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] [– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]]] or WI Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] d or APRX nnKM WID LINE BTN (nnNM WID LINE BTN) Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] [– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]][– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]] or ENTIRE FIR[/UIR] or ENTIRE CTA or TC CENTRE PSN Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] a or NO VA EXP b		—	N30 W170 N OF N30 S OF S50 AND W OF E170 S OF N46 AND N OF N39 NE OF LINE N35 W020 – N45 W040 SW OF LINE N48 W020 – N43 E010 AND NE OF LINE N43 W020 – N38 E010 WI N20 W090 – N05 W090 – N10 W100 – N20 W100 – N20 W090 APRX 50KM WID LINE BTN N64 W017 – N57 W005 – N55 E010 – N55 E030 ENTIRE FIR ENTIRE FIR/UIR ENTIRE CTA TC CENTRE PSN N2740 W07345 NO VA EXP	—
Repetition of elements (C) c	Repetition of elements included in a SIGMET for volcanic ash cloud or tropical cyclone	[AND]		—	AND	—
OR
Cancellation of SIGMET/AIRMET (C)	Cancellation of SIGMET/AIRMET referring to its identification	CNL SIGMET nnn nnnnnn/nnnnnn or CNL SIGMET nnn nnnnnn/nnnnnn [VA MOV TO nnnn FIR] b		CNL AIRMET [n][n]n nnnnnn/nnnnnn	CNL SIGMET B04 101200/101600 CNL SIGMET I07 251030/251430 VA MOV TO YUDO FIR	CNL AIRMET 05 151520/151800

Appendix 5B Template for special air-reports (uplink)

Key:

M

=

inclusion mandatory, part of every special air-report (uplink);

C

=

inclusion conditional, whenever applicable;

=

=

a double line indicates that the text following it shall be placed on the subsequent line.

Note: the ranges and resolutions for the numerical elements included in special air-reports are shown in Appendix 8. U.K.

Element	Detailed content	Template	Examples
Identification (M)	Special air-report (uplink) identification	ARS	ARS
Aircraft Identification (M)	Aircraft radiotelephony call sign	nnnnnn	VA812
Observed phenomenon (M)	Description of observed phenomenon causing the issuance of the special air-report	TS TSGR SEV TURB SEV ICE SEV MTW HVY SS VA CLD VA [MT nnnnnnnnnn] MOD TURB MOD ICE	TSGR SEV TURB SEV ICE SEV MTW HVY SS VA CLD VA VA MT ASHVAL5 MOD TURB MOD ICE
Observation time (M)	Time of observation of observed phenomenon	OBS AT nnnnZ	OBS AT 1210Z
Location (C)	Location (referring to latitude and longitude (in degrees and minutes)) of observed phenomenon	NnnnnWnnnnn or NnnnnEnnnnn or SnnnnWnnnnn or SnnnnEnnnnn	N2020W07005 S4812E01036
Level (C)	Flight level or altitude of observed phenomenon	FLnnn or FLnnn/nnn or nnnnM (or [n]nnnnFT)	FL390 FL180/210 3000M 12000FT;]

[F1 Appendix 6 Template for advisory for volcanic ash

Key:

M

=

inclusion mandatory;

O

=

inclusion optional;

=

=

a double line indicates that the text following it shall be placed on the subsequent line.

Note 1: the ranges and resolutions for the numerical elements included in volcanic ash advisory are shown in Appendix 8. U.K.

Note 2: the explanations for the abbreviations can be found in ICAO Doc 8400 ‘ Procedures for Air Navigation Services —Abbreviations and Codes (PANS-ABC) ’ . U.K.

Note 3: inclusion of a ‘ colon ’ after each element heading is mandatory. U.K.

Note 4: numbers 1 to 18 are included only for clarity and they are not part of the advisory, as shown in the example. U.K.

a Up to 4 selected layers.
b If volcanic ash cloud is reported (e.g. AIREP) but not identifiable from the satellite data.
Element		Detailed content	Template(s)		Examples
1	Identification of the type of message (M)	Type of message	VA ADVISORY		VA ADVISORY
2	Time of origin (M)	Year, month, day, time in UTC	DTG:	nnnnnnnn/nnnnZ	DTG:	20080923 /0130Z
3	Name of VAAC (M)	Name of VAAC	VAAC:	nnnnnnnnnnnn	VAAC:	TOKYO
4	Name of volcano (M)	Name and International Association of Volcanology and Chemistry of the Earth’s Interio (IAVCEI) number of volcano	VOLCANO:	nnnnnnnnnnnnnnnnnnnnnn [nnnnnn] or UNKNOWN or UNNAMED	VOLCANO: VOLCANO:	KARYMSKY 1000-13 UNNAMED
5	Location of volcano (M)	Location of volcano in degrees and minutes	PSN:	Nnnnn or Snnnn Wnnnnn or Ennnnn or UNKNOWN	PSN: PSN:	N5403 E15927 UNKNOWN
6	State or region (M)	State, or region if ash is not reported over a State	AREA:	nnnnnnnnnnnnnnnn	AREA:	RUSSIA
7	Summit elevation (M)	Summit elevation in m (or ft)	SUMMIT ELEV:	nnnnM (or nnnnnFT)	SUMMIT ELEV:	1536M
8	Advisory number (M)	Advisory number: year in full and message number (separate sequence for each volcano)	ADVISORY NR:	nnnn/nnnn	ADVISORY NR:	2008/4
9	Information source (M)	Information source using free text	INFO SOURCE:	Free text up to 32 characters	INFO SOURCE:	MTSAT-1R KVERT KEMSD
10	Colour code (O)	Aviation colour code	AVIATION COLOUR CODE:	RED or ORANGE or YELLOW or GREEN or UNKNOWN or NOT GIVEN or NIL	AVIATION COLOUR CODE:	RED
11	Eruption details (M)	Eruption details (including date/time of eruption(s))	ERUPTION DETAILS:	Free text up to 64 characters or UNKNOWN	ERUPTION DETAILS:	ERUPTION AT 20080923 /0000Z FL300 REPORTED
12	Time of observation (or estimation) of volcanic ash clouds (M)	Day and time (in UTC) of observation (or estimation) of volcanic ash clouds	OBS (or EST) VA DTG:	nn/nnnnZ	OBS VA DTG:	23/0100Z
13	Observed or estimated volcanic ash clouds (M)	Horizontal (in degrees and minutes) and vertical extent at the time of observation of the observed or estimated volcanic ash clouds or, if the base is unknown, the top of the observed or estimated volcanic ash clouds; Movement of the observed or estimated volcanic ash clouds	OBS VA CLD or EST VA CLD:	TOP FLnnn or SFC/FLnnn or FLnnn/nnn [nnKM WID LINE BTN (nnNM WID LINE BTN)] Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn][– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]] MOV N nnKMH (or KT) or MOV NE nnKMH (or KT) or MOV E nnKMH (or KT) or MOV SE nnKMH (or KT) or MOV S nnKMH (or KT) or MOV SW nnKMH (or KT) or MOV W nnKMH (or KT) or MOV NW nnKMH (or KT) or VA NOT IDENTIFIABLE FM SATELLITE DATA WIND FLnnn/nnn nnn/nn[n]MPS (or KT) a or WIND FLnnn/nnn VRBnnMPS (or KT) or WIND SFC/FLnnn nnn/nn[n]MPS (or KT) or WIND SFC/FLnnn VRBnnMPS (or KT)	OBS VA CLD:	FL250/300 N5400 E15930 – N5400 E16100 – N5300 E15945 MOV SE 20KT SFC/FL200 N5130 E16130 – N5130 E16230 – N5230 E16230 – N5230 E16130 MOV SE 15KT TOP FL240 MOV W 40KMH VA NOT IDENTIFIABLE FM SATELLITE DATA WIND FL050/070 180/12MPS
14	Forecast height and position of the volcanic ash clouds (+ 6 HR) (M)	Day and time (in UTC) (6 hours from the ‘ Time of observation (or estimation) of volcanic ash clouds ’ given in Item 12); Forecast height and position (in degrees and minutes) for each volcanic ash cloud mass for that fixed valid time	FCST VA CLD +6 HR:	nn/nnnnZ SFC or FLnnn/[FL]nnn [nnKM WID LINE BTN (nnNM WID LINE BTN)] Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn][– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]] b or NO VA EXP or NOT AVBL or NOT PROVIDED	FCST VA CLD +6 HR:	23/0700Z FL250/350 N5130 E16030 – N5130 E16230 – N5330 E16230 – N5330 E16030 SFC/FL180 N4830 E16330 – N4830 E16630 – N5130 E16630 – N5130 E16330 NO VA EXP NOT AVBL NOT PROVIDED
15	Forecast height and position of the volcanic ash clouds (+ 12 HR) (M)	Day and time (in UTC) (12 hours from the ‘ Time of observation (or estimation) of volcanic ash clouds ’ given in Item 12); Forecast height and position (in degrees and minutes) for each volcanic ash cloud mass for that fixed valid time	FCST VA CLD +12 HR:	nn/nnnnZ SFC or FLnnn/[FL]nnn [nnKM WID LINE BTN (nnNM WID LINE BTN)] Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]] or NO VA EXP or NOT AVBL or NOT PROVIDED	FCST VA CLD +12 HR:	23/1300Z SFC/FL270 N4830 E16130 – N4830 E16600 – N5300 E16600 – N5300 E16130 NO VA EXP NOT AVBL NOT PROVIDED
16	Forecast height and position of the volcanic ash clouds (+ 18 HR) (M)	Day and time (in UTC) (18 hours from the ‘ Time of observation (or estimation) of volcanic ash clouds ’ given in Item 12); Forecast height and position (in degrees and minutes) for each volcanic ash cloud mass for that fixed valid time	FCST VA CLD +18 HR:	nn/nnnnZ SFC or FLnnn/[FL]nnn [nnKM WID LINE BTN (nnNM WID LINE BTN)] Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn] – Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]– Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]] or NO VA EXP or NOT AVBL or NOT PROVIDED	FCST VA CLD +18 HR:	23/1900Z NO VA EXP NOT AVBL NOT PROVIDED
17	Remarks (M)	Remarks, as necessary	RMK:	Free text up to 256 characters or NIL	RMK:	LATEST REP FM KVERT (0120Z) INDICATES ERUPTION HAS CEASED. TWO DISPERSING VA CLD ARE EVIDENT ON SATELLITE IMAGERY NIL
18	Next advisory (M)	Year, month, day and time in UTC	NXT ADVISORY:	nnnnnnnn/nnnnZ or NO LATER THAN nnnnnnnn/nnnnZ or NO FURTHER ADVISORIES or WILL BE ISSUED BY nnnnnnnn/nnnnZ	NXT ADVISORY:	20080923 /0730Z NO LATER THAN nnnnnnnn/nnnnZ NO FURTHER ADVISORIES WILL BE ISSUED BY nnnnnnnn/nnnnZ

Appendix 7 Template for advisory for tropical cyclones

Key:

=

=

a double line indicates that the text following it shall be placed on the subsequent line.

Note 1: the ranges and resolutions for the numerical elements included in tropical cyclone advisory are shown in Appendix 8. U.K.

Note 2: the explanations for the abbreviations can be found in ICAO Doc 8400 ‘Procedures for Air Navigation Services – Abbreviations and Codes (PANS-ABC). U.K.

Note 3: all the elements are mandatory. U.K.

Note 4: inclusion of a ‘ colon ’ after each element heading is mandatory. U.K.

Note 5: numbers 1 to 19 are included only for clarity and they are not part of the advisory, as shown in the example. U.K.

Element		Detailed content	Template(s)		Examples
1	Identification of the type of message	Type of message	TC ADVISORY		TC ADVISORY
2	Time of origin	Year, month, day and time in UTC of issue	DTG:	nnnnnnnn/nnnnZ	DTG:	20040925 /1600Z
3	Name of TCAC	Name of TCAC (location indicator or full name)	TCAC:	nnnn or nnnnnnnnnn	TCAC: TCAC:	YUFO MIAMI
4	Name of tropical cyclone	Name of tropical cyclone or ‘ NN ’ for unnamed tropical cyclone	TC:	nnnnnnnnnnnn or NN	TC:	GLORIA
5	Advisory number	Advisory number (starting with ‘ 01 ’ for each tropical cyclone)	NR:	nn	NR:	01
6	Position of the centre	Position of the centre of the tropical cyclone (in degrees and minutes)	PSN:	Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]	PSN:	N2706 W07306
7	Direction and speed of movement	Direction and speed of movement given in 16 compass points and km/h (or kt), respectively, or moving slowly (< 6 km/h (3 kt)) or stationary (< 2 km/h (1 kt))	MOV:	N nnKMH (or KT) or NNE nnKMH (or KT) or NE nnKMH (or KT) or ENE nnKMH (or KT) or E nnKMH (or KT) or ESE nnKMH (or KT) or SE nnKMH (or KT) or SSE nnKMH (or KT) or S nnKMH (or KT) or SSW nnKMH (or KT) or SW nnKMH (or KT) or WSW nnKMH (or KT) or W nnKMH (or KT) or WNW nnKMH (or KT) or NW nnKMH (or KT) or NNW nnKMH (or KT) or SLW or STNR	MOV:	NW 20KMH
8	Central pressure	Central pressure (in hPa)	C:	nnnHPA	C:	965HPA
9	Maximum surface wind	Maximum surface wind near the centre (mean surface wind over 10 minutes, in m/s (or kt))	MAX WIND:	nn[n]MPS (or nn[n]KT)	MAX WIND:	22MPS
10	Forecast of centre position (+ 6 HR)	Day and time (in UTC) (6 hours from the DTG given in Item 2); forecast position (in degrees and minutes) of the centre of the tropical cyclone	FCST PSN +6 HR:	nn/nnnnZ Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]	FCST PSN +6 HR:	25/2200Z N2748 W07350
11	Forecast of maximum surface wind (+ 6 HR)	Forecast of maximum surface wind (6 hours after the DTG given in Item 2)	FCST MAX WIND +6 HR:	nn[n]MPS (or nn[n]KT)	FCST MAX WIND +6 HR:	22MPS
12	Forecast of centre position (+ 12 HR)	Day and time (in UTC) (12 hours from the DTG given in Item 2); forecast position (in degrees and minutes) of the centre of the tropical cyclone	FCST PSN +12 HR:	nn/nnnnZ Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]	FCST PSN +12 HR:	26/0400Z N2830 W07430
13	Forecast of maximum surface wind (+ 12 HR)	Forecast of maximum surface wind (12 hours after the DTG given in Item 2)	FCST MAX WIND +12 HR:	nn[n]MPS (or nn[n]KT)	FCST MAX WIND +12 HR:	22MPS
14	Forecast of centre position (+ 18 HR)	Day and time (in UTC) (18 hours from the DTG given in Item 2); forecast position (in degrees and minutes) of the centre of the tropical cyclone	FCST PSN +18 HR:	nn/nnnnZ Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]	FCST PSN +18 HR:	26/1000Z N2852 W07500
15	Forecast of maximum surface wind (+ 18 HR)	Forecast of maximum surface wind (18 hours after the DTG given in Item 2)	FCST MAX WIND +18 HR:	nn[n]MPS (or nn[n]KT)	FCST MAX WIND +18 HR:	21MPS
16	Forecast of centre position (+ 24 HR)	Day and time (in UTC) (24 hours a day and seven days a week from the DTG given in Item 2); forecast position (in degrees and minutes) of the centre of the tropical cyclone	FCST PSN +24 HR:	nn/nnnnZ Nnn[nn] or Snn[nn] Wnnn[nn] or Ennn[nn]	FCST PSN +24 HR:	26/1600Z N2912 W07530
17	Forecast of maximum surface wind (+ 24 HR)	Forecast of maximum surface wind (24 hours a day and seven days a week after the DTG given in Item 2)	FCST MAX WIND +24 HR:	nn[n]MPS (or nn[n]KT)	FCST MAX WIND +24 HR:	20MPS
18	Remarks	Remarks, as necessary	RMK:	Free text up to 256 characters or NIL	RMK:	NIL
19	Expected time of issuance of next advisory	Expected year, month, day and time (in UTC) of issuance of next advisory	NXT MSG:	[BFR] nnnnnnnn/nnnnZ or NO MSG EXP	NXT MSG:	20040925 /2000Z

Appendix 8 Ranges and resolutions for the numerical elements included in volcanic ash advisory, tropical cyclone advisory, SIGMET, AIRMET, aerodrome warning and wind shear warning

a Non-dimensional.; ]
Elements		Range	Resolution
Summit elevation:	M	000–8 100	1
	FT	000–27 000	1
Advisory number:	for VA (index) a	000–2 000	1
	for TC (index) a	00–99	1
Maximum surface wind:	MPS	00–99	1
	KT	00–199	1
Central pressure:	hPa	850–1 050	1
Surface wind speed:	MPS	15–49	1
	KT	30–99	1
Surface visibility:	M	0000–0750	50
	M	0800–5 000	100
Cloud: height of base:	M	000–300	30
	FT	000–1 000	100
Cloud: height of top:	M	000–2 970	30
	M	3 000–20 000	300
	FT	000–9 900	100
	FT	10 000–60 000	1 000
Latitudes:	° (degrees)	00–90	1
	(minutes)	00–60	1
Longitudes:	° (degrees)	000–180	1
	(minutes)	00–60	1
Flight levels:		000–650	10
Movement:	KMH	0–300	10
	KT	0–150	5