JEPPESEN GENERAL AIRWAY MANUAL (Issue Date 1 JUL 21)

4. airlines requiring the advisory information through the AFTN address provided specifi-

cally for this purpose; and
NOTE: The AFTN address to be used by the VAACs is given in the Handbook on the
International Airways Volcano Watch (IAVW) — Operational Procedures and Contact
List (Doc 9766) which is available on the ICAO website.

d. issuing updated advisory information to the MWOs, ACCs, FICs and VAACs referred to in c).

as necessary, but at least six hours until such time as:

1. the volcanic ash “cloud” is no longer identifiable from satellite data and, where available,

ground-based and airborne data;

2. no further reports of volcanic ash are received from the area; and
3. no further eruptions of the volcano are reported.

3.5.2 VAACs shall maintain a 24-hour watch.
3.5.3 In case of interruption of the operation of a VAAC, its functions shall be carried out by
another VAAC or another meteorological center, as designated by the VAAC Provider State con-
cerned.
NOTE: Back-up procedures to be used in case of interruption of the operation of a VAAC are
included in Doc 9766.

STATE VOLCANO OBSERVATORIES

Contracting States with active or potentially active volcanoes shall arrange that State volcano
observatories monitor these volcanoes and when observing:

a. significant pre-eruption volcanic activity, or a cessation thereof;
b. a volcanic eruption, or a cessation thereof; and/or

c. volcanic ash in the atmosphere

shall send this information as quickly as practicable to their associated ACC/FIC, MWO and
VAAC.
NOTE 1: Pre-eruption volcanic activity in this context means unusual and/or increasing volcanic
activity which could presage a volcanic eruption.
NOTE 2: Doc 9766 contains guidance material about active and potentially active volcanoes.

TROPICAL CYCLONE ADVISORY CENTERS

A Contracting State having accepted, by regional air navigation agreement, the responsibility for
providing a TCAC shall arrange for that center to:

a. monitor the development of tropical cyclones in its area of responsibility, using geostationary

and polar-orbiting satellite data, radar data and other meteorological information;

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b. issue advisory information concerning the position of the cyclone center, its direction and

speed of movement, central pressure and maximum surface wind near the center, in abbre-
viated plain language to:

1. MWOs in its area of responsibility;
2. other TCACs whose area of responsibility may be affected; and
3. WAFCs, international OPMET databanks, and centers designated by regional air navi-

gation agreement for the operation of aeronautical fixed service Internet-based serv-
ices; and

c. issue updated advisory information to MWOs for each tropical cyclone, as necessary, but at

least every 6 hours.

SPACE WEATHER CENTERS

3.8.1 A contracting State, having accepted the responsibility for providing a space weather
center (SWXC), shall arrange for that center to monitor and provide advisory information on space
weather phenomena in its area of responsibility by arranging for that center to:

a. monitor relevant ground-based, airborne and space-based observations to detect, and pre-

dict when possible, the existence of space weather phenomena that have an impact in the
following areas:

1. high frequency (HF) radio communications;
2. communications via satellite;
3. GNSS-based navigation and surveillance; and
4. radiation exposure at flight levels;

b. issue advisory information regarding the extent, severity and duration of the space weather

phenomena that have an impact referred to in a);

c. supply the advisory information referred to in b) to:

1. area control centres, flight information centers and aerodrome meteorological offices in

its area of responsibility which may be affected;

2. other SWXCs; and
3. international OPMET databanks, international NOTAM offices and aeronautical fixed

service Internet-based services.

3.8.2 SWXC shall maintain a 24-hour watch.
3.8.3 In case of interruption of the operation of a SWXC, its functions shall be carried out by
another SWXC or another center, as designated by the SWXC Provider State concerned.
NOTE: Guidance on the provision of space weather advisory information, including the lCAO-des-
ignated provider(s) of space weather advisory information, is provided in the Manual on Space
Weather Information in Support of International Air Navigation (Doc 10100).

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CHAPTER 4 – METEOROLOGICAL OBSERVATIONS AND REPORTS

NOTE: Technical specifications related to this Chapter are given in Appendix 3.

AERONAUTICAL METEOROLOGICAL STATIONS AND

OBSERVATIONS

4.1.1  Each Contracting State shall establish, at aerodromes in its territory; such aeronautical
meteorological stations as it determines to be necessary. An aeronautical meteorological station
may be a separate station or may be combined with a synoptic station.
NOTE: Aeronautical meteorological stations may include sensors installed outside the aerodrome,
where considered justified, by the meteorological authority to ensure the compliance of meteoro-
logical service for international air navigation with the provisions of Annex 3.
4.1.2  Recommendation – Each Contracting State should establish, or arrange for the establish-
ment of, aeronautical meteorological stations on off-shore structures or at other points of signifi-
cance in support of helicopter operations to off-shore structures, if required by regional air naviga-
tion agreement.
4.1.3  Aeronautical meteorological stations shall make routine observations at fixed intervals. At
aerodromes, the routine observations shall be supplemented by special observations whenever
specified changes occur in respect of surface wind, visibility, runway visual range, present
weather, clouds and/or air temperature.
4.1.4  Each Contracting State should arrange for its aeronautical meteorological stations to be
inspected at sufficiently frequent intervals to ensure that a high standard of observations is main-
tained, that instruments and all their indicators are functioning correctly, and that the exposure of
the instruments has not changed significantly.
NOTE: Guidance on the inspection of aeronautical meteorological stations including the fre-
quency of inspections is given in the Manual on Automatic Meteorological Observing Systems at
Aerodromes (Doc 9837).
4.1.5  At aerodromes, with runways intended for Category II and III instrument approach and
landing operations, automated equipment for measuring or assessing, as appropriate, and for
monitoring and remote indicating of surface wind, visibility, runway visual range, height of cloud
base, air and dew-point temperatures and atmospheric pressure shall be installed to support
approach and landing and take-off operations. These devices shall be integrated automatic sys-
tems for acquisition, processing, dissemination and display in real time of the meteorological
parameters affecting landing and take-off operations. The design of integrated automatic systems
shall observe human factors principles and include back-up procedures.
NOTE 1: Categories of precision approach and landing operations are defined in Annex 6, Part I.
NOTE 2: Guidance material on the application of human factors principles can be found in the
Human Factors Training Manual (Doc 9683).
4.1.6  Recommendation – At aerodromes, with runways intended for Category I instrument
approach and landing operations, automated equipment for measuring or assessing, as appropri-
ate, and for monitoring and remote indicating of surface wind, visibility, runway visual range,

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height of cloud base, air and dew-point temperatures and atmospheric pressure should be instal-
led to support approach and landing and take-off operations. These devices should be integrated
automatic systems for acquisition, processing, dissemination and display in real time of the mete-
orological parameters affecting landing and take-off operations. The design of integrated auto-
matic systems should observe human factors principles and include back-up procedures.
4.1.7 Recommendation – Where an integrated semi-automatic system is used for the dissemi-
nation/display of meteorological information, it should be capable of accepting the manual inser-
tion of data covering those meteorological elements which cannot be observed by automatic
means.
4.1.8 The observations shall form the basis for the preparation of reports to be disseminated at
the aerodrome of origin and for reports to be disseminated beyond the aerodrome of origin.

AGREEMENT BETWEEN METEOROLOGICAL AUTHORITIES AND AIR

TRAFFIC SERVICES AUTHORITIES

Recommendation – An agreement between the meteorological authority and the appropriate
ATS authority should be established to cover, among other things:

a. the provision in air traffic services units of displays related to integrated automatic systems;
b. the calibration and maintenance of these displays/instruments;

c. the use to be made of the displays/instruments by air traffic services personnel;

d. as and where necessary, supplementary visual observations (e.g. of meteorological phe-

nomena of operational significance in the climb-out and approach areas) if and when made
by air traffic services personnel to update or supplement the information supplied by the
meteorological station;

e. meteorological information obtained from aircraft taking off or landing (e.g. on wind shear);

and

f. if available, meteorological information obtained from ground weather radar.

NOTE: Guidance on the subject of coordination between ATS and meteorological services is con-
tained in the Manual on Coordination between Air Traffic services, Aeronautical Information Serv-
ices and Aeronautical Meteorological Services (Doc 9377).

ROUTINE OBSERVATIONS AND REPORTS

4.3.1 At aerodromes, routine observations shall be made throughout the 24 hours each day,
except as otherwise agreed between the meteorological authority, the appropriate ATS authority
and the operator concerned. Such observations shall be made at intervals of one hour or, if so
determined by regional air navigation agreement, at intervals of one half-hour. At other aeronauti-
cal meteorological stations, such observations shall be made as determined by the meteorological
authority taking into account the requirements of air traffic services units and aircraft operations.
4.3.2 Reports of routine observations shall be issued as:

a. local routine reports only for dissemination at the aerodrome of origin (intended for arriving

and departing aircraft); and

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b. METAR for dissemination beyond the aerodrome of origin (mainly intended for flight plan-

ning, VOLMET broadcasts and D-VOLMET).

NOTE: Meteorological information used in ATIS (voice-ATIS and D-ATIS) is to be extracted from
the local routine report, in accordance with Annex 11, 4.3.6.1 g).
4.3.3 At aerodromes that are not operational throughout 24 hours in accordance with 4.3.1,
METAR shall be issued prior to the aerodrome resuming operations in accordance with regional
air navigation agreement.

SPECIAL OBSERVATIONS AND REPORTS

4.4.1 A list of criteria for special observations shall be established by the meteorological author-
ity, in consultation with the appropriate ATS authority, operators and others concerned.
4.4.2 Reports of special observations shall be issued as:

a. local special reports, only for dissemination at the aerodrome of origin (intended for arriving

and departing aircraft); and

b. SPECI for dissemination beyond the aerodrome of origin (mainly intended for flight planning,

VOLMET broadcasts and D-VOLMET) unless METAR are issued at half-hourly intervals.

NOTE: Meteorological information used in ATIS (voice-ATIS and D-ATIS) is to be extracted from
the local special report, in accordance with Annex 11, 4.3.6.1 g).
4.4.3 At aerodromes that are operational throughout 24 hours in accordance with 4.3.1, follow-
ing the resumption of the issuance of METAR, SPECI shall be issued, as necessary.

CONTENTS OF REPORTS

4.5.1 Local routine, local special reports, METAR and SPECI shall contain the following ele-
ments in the order indicated:

a. identification of the type of report;
b. location indicator;

c. time of the observation;

d. identification of an automated or missing report, when applicable;
e. surface wind direction and speed;

f. visibility;

g. runway visual range, when applicable;
h. present weather;

i. cloud amount, cloud type (only for cumulonimbus and towering cumulus clouds) and height

of cloud base or, where measured, vertical visibility;

j. air temperature and dew-point temperature; and

k. QNH and, when applicable, QFE (QFE included only in local routine and special reports).

4.4

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NOTE: The location indicators referred to under b. and their significations are published in Loca-
tion Indicators Doc 7910).
4.5.2 Recommendation – In addition to elements listed under 4.5.1 a) to k) local routine and
special reports and METAR and SPECI should contain supplementary information to be placed
after element k).
4.5.3 Optional elements included under supplementary information shall be included in METAR
and SPECI in accordance with regional air navigation agreement.

OBSERVING AND REPORTING METEOROLOGICAL ELEMENTS

Surface Wind

4.6.1.1  The mean direction and the mean speed of the surface wind shall be measured, as well
as significant variations of wind direction and speed, and reported in degrees true and meters per
second (or knots), respectively.
4.6.1.2  Recommendation – When local routine and special reports are used for departing air-
craft, the surface wind observations for these reports should be representative of conditions along
the runway; when local routine and special reports are used for arriving aircraft, the surface wind
observations for these reports should be representative of the touchdown zone.
4.6.1.3  Recommendation – For METAR and SPECI, the surface wind observations should be
representative of conditions above the whole runway where there is only one runway and the
whole runway complex where there is more than one runway.

Visibility

4.6.2.1  The visibility as defined in Chapter 1 shall be measured or observed, and reported in
meters or kilometers.
4.6.2.2  Recommendation – When local routine and special reports are used for departing air-
craft, the visibility observations for these reports should be representative of conditions along the
runway; when local routine and special reports are used for arriving aircraft, the visibility observa-
tions for these reports should be representative of the touchdown zone of the runway.
4.6.2.3  Recommendation – For METAR and SPECI the visibility observations should be repre-
sentative of the aerodrome.

Runway Visual Range

NOTE: Guidance on the subject of runway visual range is contained in the Manual of Runway
Visual Range Observing and Reporting Practices (Doc 9328).
4.6.3.1 Runway visual range as defined in Chapter 1 shall be assessed on all runways intended
for Category II and III instrument approach and landing operations.
4.6.3.2 Recommendation – Runway visual range as defined in Chapter 1 should be assessed
on all runways intended for use during periods of reduced visibility, including:

a. precision approach runways intended for Category I instrument approach and landing opera-

tions; and

4.6

4.6.1

4.6.2

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b. runways used for take-off and having high-intensity edge lights and/or center line lights.

NOTE: Precision approach runways are defined in Annex 14, Volume I, Chapter 1, under ‘Instru-
ment runway’.
4.6.3.3 The runway visual range, assessed in accordance with 4.6.3.1 and 4.6.3.2, shall be
reported in meters throughout periods when either the visibility or the runway visual range is less
than 1500m.
4.6.3.4 Runway visual range assessments shall be representative of:

a. the touchdown zone of the runway intended for non-precision or Category I instrument

approach and landings operations;

b. the touchdown zone and the mid-point of the runway intended for Category II instrument

approach and landing operations; and

c. the touchdown zone, the mid-point and stop-end of the runway intended for Category III

instrument approach and landing operations.

4.6.3.5 The units providing air traffic service and aeronautical information service for an aero-
drome shall be kept informed without delay of changes in the serviceability status of the automa-
ted equipment used for assessing runway visual range.

Present Weather

4.6.4.1  The present weather occurring at the aerodrome vicinity shall be observed and reported
as necessary. The following present weather phenomena shall be identified, as a minimum: rain,
dizzle, snow and freezing precipitation (including intensity thereof), haze, mist, fog, freezing fog
and thunderstorms (including thunderstorms in the vicinity).
4.6.4.2  Recommendation – For local routine and special reports, the present weather informa-
tion should be representative of conditions at the aerodrome.
4.6.4.3  Recommendation – For METAR and SPECl, the present weather information should be
representative of conditions at the aerodrome and, for certain specified present weather phenom-
ena, in its vicinity.

Clouds

4.6.5.1  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, in lieu of cloud amount, cloud type and
height of cloud base. The height of cloud base and vertical visibility shall be reported in meters (or
feet).
4.6.5.2  Recommendation – Cloud observations for local routine and special reports should be
representative of the runway threshold(s) in use.
4.6.5.3  Recommendation – Cloud observations for METAR and SPECI should be representa-
tive of the aerodrome and its vicinity.

4.6.4

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Air Temperature and Dew-Point Temperature

4.6.6.1 The air temperature and the dew-point temperature shall be measured and reported in
degrees Celsius.
4.6.6.2 Recommendation – Observation of air temperature and dew-point temperature for local
routine and special reports and METAR and SPECI should be representative for the whole
runway complex.

Atmospheric Pressure

The atmospheric pressure shall be measured, and QNH and QFE values shall be computed and
reported in hectopascals.

Supplementary Information

Recommendation – Observations made at aerodromes should include the available supplemen-
tary information concerning significant meteorological conditions, particularly those in the
approach and climb-out areas. Where practicable, the information should identify the location of
the meteorological condition.

REPORTING METEOROLOGICAL INFORMATION FROM AUTOMATIC

OBSERVING SYSTEMS

4.7.1  Recommendation – METAR and SPECI from automatic observing systems should be
used by States in a position to do so during non-operational hours of the aerodrome, and during
operational hours of the aerodrome as determined by the meteorological authority in consultation
with users based on the availability and efficient use of personnel.
NOTE: Guidance on the use of automatic meteorological observing systems is given in Doc 9837.
4.7.2  Recommendation – Local routine and special reports from automatic systems should be
used by States in a position to do so during operational hours of the aerodrome as determined by
the meteorological authority in consultation with users based on the availability and efficient use
of personnel.
4.7.3  Local routine and special reports and METAR and SPECI from automatic observing sys-
tems shall be identified with the word "AUTO".

OBSERVATIONS AND REPORTS OF VOLCANIC ACTIVITY

Recommendation – The occurrence of pre-eruption volcanic activity, volcanic eruptions and vol-
canic ash cloud should be reported without delay to the associated air traffic services unit, aero-
nautical information services unit and meteorological watch office. The report should be made in
the form of a volcanic activity report comprising the following information in the order indicated:

a. message type, VOLCANIC ACTIVITY REPORT;
b. station identifier, location indicator or name of station;

c. date/time of message;

d. location of volcano and name, if known; and

4.6.6

4.6.7

4.6.8

4.7

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e. concise description of event including, as appropriate, level of intensity of volcanic activity,

occurrence of an eruption and its date and time and the existence of a volcanic ash cloud in
the area together with direction of ash cloud movement and height.

NOTE: Pre-eruption volcanic activity in this context means unusual and/or increasing volcanic
activity which could presage a volcanic eruption.

CHAPTER 5 – AIRCRAFT OBSERVATIONS AND REPORTS

NOTE: Technical specifications related to this Chapter are given in Appendix 4.

OBLIGATIONS OF STATES

Each Contracting State shall arrange, according to the provisions of this chapter, for observations
to be made by aircraft of its registry operating on international air routes and for the recording and
reporting of these observations.

TYPES OF AIRCRAFT OBSERVATIONS

The following aircraft observations shall be made:

a. routine aircraft observations during en-route and climb-out phases of the flight; and
b. special and other non-routine aircraft observations during any phase of the flight.

ROUTINE AIRCRAFT OBSERVATIONS – DESIGNATION

5.3.1  Recommendation – When air-ground data link is used and ADS-C or SSR Mode S is
being applied, automated routine observations should be made every 15 minutes during the en-
route phase and every 30 seconds during climb-out phase for the first 10 minutes of the flight.
5.3.2  Recommendation – For helicopter operations to and from aerodromes on off-shore struc-
tures, routine observations should be made from helicopters at points and times as agreed
between the meteorological authorities and the helicopter operators concerned.
5.3.3  In the case of air routes with high density traffic (e.g. organized tracks), an aircraft from
among the aircraft operating at each flight level shall be designated, at approximately hourly inter-
vals, to make routine observations in accordance with 5.3.1. The designation procedures shall be
subject to regional air navigation agreement.
5.3.4  In the case of the requirement to report during the climb-out phase, an aircraft shall be
designated, at approximately hourly intervals, at each aerodrome to make routine observations in
accordance with 5.3.1.

ROUTINE AIRCRAFT OBSERVATIONS – EXEMPTIONS

Aircraft not equipped with air-ground data link shall be exempted from making routine aircraft
observations.

SPECIAL AIRCRAFT OBSERVATIONS

Special observations shall be made by all aircraft whenever the following conditions are encoun-
tered or observed:

5.1

5.2

5.3

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a. moderate or severe turbulence; or
b. moderate or severe icing; or

c. severe mountain wave; or

d. thunderstorms, without hail, that are obscured, embedded, widespread or in squall lines; or
e. thunderstorms, with hail, that are obscured, embedded, widespread or in squall lines; or

f. heavy duststorm or heavy sandstorm; or

g. volcanic ash cloud; or
h. pre-eruption volcanic activity or a volcanic eruption.

NOTE: Pre-eruption volcanic activity in this context means unusual and/or increasing vol-
canic activity which could presage a volcanic eruption.

i. as of 5 November 2020, runway braking action encountered is not as good as reported.

OTHER NON-ROUTINE AIRCRAFT OBSERVATIONS

When other meteorological conditions not listed under 5.5, e.g. wind shear, are encountered and
which, in the opinion of the pilot-in-command, may affect the safety or markedly affect the effi-
ciency of other aircraft operations, the pilot-in-command shall advise the appropriate air traffic
services unit as soon as practicable.
NOTE: Icing, turbulence and, to a large extent, wind shear, are elements which, for the time
being, cannot be satisfactorily observed from the ground and for which in most cases aircraft
observations represent the only available evidence.

REPORTING OF AIRCRAFT OBSERVATIONS DURING FLIGHT

5.7.1  Aircraft observations shall be reported by air-ground data link. Where air-ground data link
is not available or appropriate, special and other non-routine aircraft observations during flight
shall be reported by voice communications.
5.7.2  Aircraft observations shall be reported during flight at the time the observation is made or
as soon thereafter as is practicable.
5.7.3  Aircraft observations shall be reported as air-reports.

RELAY OF AIR-REPORTS BY AIR TRAFFIC SERVICES UNITS

The meteorological authority concerned shall make arrangements with the appropriate ATS
authority to ensure that, on receipt by the ATS units of:

a. special air-reports by voice communications, the ATS units relay them without delay to their

associated meteorological watch office; and

b. routine and special air-reports by data link communications, the ATS units relay them without

delay to their associated meteorological watch office, the WAFCs and the centers designa-
ted by regional air navigation agreement for the operation of aeronautical fixed service Inter-
net-based services.

5.6

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RECORDING AND POST-FLIGHT REPORTING OF AIRCRAFT

OBSERVATIONS OF VOLCANIC ACTIVITY

Special aircraft observations of pre-eruption volcanic activity, a volcanic eruption or volcanic ash
cloud shall be recorded on the special air-report of volcanic activity form. A copy of the form shall
be included with the flight documentation provided to flights operating on routes which, in the
opinion of the meteorological authority concerned, could be affected by volcanic ash clouds.

CHAPTER 6 – FORECASTS

NOTE: Technical specifications related to this Chapter are given in Appendix 5.

USE OF FORECASTS

The issue of a new forecast by an aerodrome meteorological office, such as a routine aerodrome
forecast, shall be understood to cancel automatically any forecast of the same type previously
issued for the same place and for the same period of validity or part thereof.

AERODROME FORECASTS

6.2.1  An aerodrome forecast shall be prepared, on the basis of regional air navigation agree-
ment, by the aerodrome meteorological office designated by the meteorological authority con-
cerned.
NOTE: The aerodromes for which aerodrome forecasts are to be prepared and the period of val-
idity of these forecasts are listed in the relevant facilities and services implementation document
(FASID).
6.2.2  An aerodrome forecast shall be issued at a specified time not earlier than 1 hour prior to
the beginning of its validity period and consist of a concise statement of the expected meteorolog-
ical conditions at an aerodrome for a specified period.
6.2.3  Aerodrome forecasts and amendments thereto shall be issued as TAF and include the fol-
lowing information in the order indicated:

a. identification of the type of forecast;
b. location indicator;

c. time of issue of forecast;

d. identification of a missing forecast, when applicable;
e. date and period of validity of forecast;

f. identification of a cancelled forecast, when applicable;

g. surface wind;
h. visibility;

i. weather;
j. cloud; and

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

5.9

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Optional elements shall be included in TAF in accordance with regional air navigation agreement.
NOTE: The visibility included in TAF refers to the forecast prevailing visibility.
6.2.4  Aerodrome meteorological offices preparing TAF shall keep the forecasts under continu-
ous review and, when necessary, shall issue amendments promptly. The length of the forecast
messages and the number of changes indicated in the forecast shall be kept to a minimum.
NOTE: Guidance on methods to keep TAF under continuous review is given in Chapter 3 of the
Manual of Aeronautical Meteorological Practice (Doc 8896).
6.2.5  TAF that cannot be kept under continuous review shall be cancelled.
6.2.6  Recommendation – The period of validity of routine TAF should be not less than 6 hours
nor more than 30 hours; this period of validity should be determined by regional air navigation
agreement. Routine TAF valid for less than 12 hours should be issued every 3 hours and those
valid for 12 to 30 hours should be issued every 6 hours.
6.2.7  When issuing TAF, aerodrome meteorological offices shall ensure that not more than one
TAF is valid at an aerodrome at any given time.

LANDING FORECASTS

6.3.1  A landing forecast shall be prepared by the aerodrome meteorological office designated by
the meteorological authority concerned as determined by regional air navigation agreement; such
forecasts are intended to meet requirements of local users and of aircraft within about one hour’s
flying time from the aerodrome.
6.3.2  Landing forecasts shall be prepared in the form of a trend forecast.
6.3.3  A trend forecast shall consist of a concise statement of expected significant changes in the
meteorological conditions at that aerodrome to be appended to a local routine, local special
report, METAR or SPECI. 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.

FORECASTS FOR TAKE-OFF

6.4.1  A forecast for take-off shall be prepared by the aerodrome meteorological office designa-
ted by the meteorological authority concerned as agreed between the meteorological authority
and operators concerned.
6.4.2  Recommendation – A forecast for take-off should refer to a specified period of time and
should contain information on expected conditions over the runway complex in regard to surface
wind direction and speed and any variations thereof, temperature, pressure (QNH), and any other
elements as agreed locally.
6.4.3  Recommendation – A forecast for take-off should be supplied to operators and flight crew
members on request within the 3 hours before the expected time of departure.
6.4.4  Recommendation – Aerodrome meteorological offices preparing forecasts for take-off
should keep the forecasts under continuous review and, when necessary, should issue amend-
ments promptly.

6.3

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AREA FORECASTS FOR LOW-LEVEL FLIGHTS

6.5.1  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, the frequency of issue, the form and the fixed time or period of
validity of those forecasts and the criteria of amendments thereto shall be determined by the
meteorological authority in consultation with the users.
6.5.2  When the density of traffic operating below flight level 100 warrants the issuance of
AIRMET information in accordance with 7.2.1, area forecasts for such operations shall be pre-
pared in a format agreed upon between the meteorological authorities concerned. When abbrevi-
ated plain language is used, the forecast shall be prepared as a GAMET area forecast, employing
approved ICAO abbreviations and numerical values; when chart form is used, the forecast shall
be prepared as a combination of forecasts of upper wind and upper-air temperature, and of
SIGWX phenomena. The area forecasts shall be issued to cover the layer between 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 sup-
port of the issuance of AIRMET information, and additional information required by low-level
flights.
6.5.3  Area forecasts for low-level flights prepared in support of the issuance of AIRMET informa-
tion shall be issued every 6 hours for a validity of 6 hours and transmitted to meteorological watch
offices and/or aerodrome meteorological offices concerned not later than one hour prior to the
beginning of their validity period.

CHAPTER 7 – SIGMET AND AIRMET INFORMATION, AERODROME

WARNINGS AND WIND SHEAR WARNINGS AND ALERTS

NOTE: Technical specifications related to this Chapter are given in Appendix 6.

SIGMET INFORMATION

7.1.1  SIGMET information shall be issued by a meteorological watch office and shall give a con-
cise description in abbreviated plain language concerning the occurrence or expected occurrence
of specified en-route weather and other phenomena in the atmosphere that may affect the safety
of aircraft operations, and of the development of those phenomena in time and space.
7.1.2  SIGMET information shall be cancelled when the phenomena are no longer occurring or
are no longer expected to occur in the area.
7.1.3  The period of validity of a SIGMET message shall be not more than 4 hours. In the special
case of SIGMET messages for volcanic ash cloud and tropical cyclones, the period of validity
shall be extended up to 6 hours.
7.1.4  Recommendation – SIGMET messages concerning volcanic ash cloud and tropical
cyclones should be based on advisory information provided by VAACs and TCACs, respectively,
designated by regional air navigation agreement.

6.5

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7.1.5 Close coordination shall be maintained between the meteorological watch office and the
associated area control center/flight information center to ensure that information on volcanic ash
included in SIGMET and NOTAM messages is consistent.
7.1.6 SIGMET messages shall be issued not more than 4 hours before the commencement of
the period of validity. In the special case of SIGMET messages for volcanic ash cloud and tropical
cyclones, these messages shall be issued as soon as practicable but not more than 12 hours
before the commencement of the period of validity. SIGMET messages for volcanic ash and tropi-
cal cyclones shall be updated at least every 6 hours.

AIRMET INFORMATION

7.2.1  AIRMET information shall be issued by a meteorological watch office in accordance with
regional air navigation agreement, taking into account the density of the air traffic operating below
flight level 100. AIRMET information shall give a concise description in abbreviated plain lan-
guage concerning the occurrence and/or expected occurrence of specified en-route weather phe-
nomena, which have not been included in Section I of the area forecast for low-level flights issued
in accordance with Chapter 6, section 6.5 and which may affect the safety of low-level flights, and
of the development of those phenomena in time and space.
7.2.2  AIRMET information shall be cancelled when the phenomena are no longer occurring or
are no longer expected to occur in the area.
7.2.3  The period of validity of an AIRMET message shall be not more than 4 hours.

AERODROME WARNINGS

7.3.1 Aerodrome warnings shall be issued by the aerodrome meteorological office designated
by the meteorological authority concerned and shall give concise information of meteorological
conditions which could adversely affect aircraft on the ground, including parked aircraft, and the
aerodrome facilities and services.
7.3.2 Recommendation – Aerodrome warnings should be cancelled when the conditions are no
longer occurring and/or no longer expected to occur at the aerodrome.

WIND SHEAR WARNINGS AND ALERTS

NOTE: Guidance on the subject is contained in the Manual on Low-level Wind Shear (Doc 9817).
Wind shear alerts are expected to complement wind shear warnings and together are intended to
enhance situational awareness of wind shear.
7.4.1 Wind shear warnings shall be prepared by the aerodrome meteorological office designated
by the meteorological authority concerned for aerodromes where wind shear is considered a
factor, in accordance with local arrangements with the appropriate ATS unit and operators con-
cerned. Wind shear warnings shall give concise information on the observed or expected exis-
tence of wind shear which could adversely affect aircraft on the approach path or take-off path or
during circling approach between runway level and 500m (1600ft) above that level and aircraft on
the runway during the landing roll or take-off run. Where local topography has been shown to pro-
duce significant wind shears at heights in excess of 500m (1600ft) above runway level, then 500m
(1600ft) shall not be considered restrictive.

7.2

7.3

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7.4.2  Recommendation – Wind shear warnings for arriving aircraft and/or departing aircraft
should be cancelled when aircraft reports indicate that wind shear no longer exists or, alterna-
tively, after an agreed elapsed time. The criteria for the cancellation of a wind shear warning
should be defined locally for each aerodrome, as agreed between the meteorological authority,
the appropriate ATS authority and the operators concerned.
7.4.3  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 shall be
issued. Wind shear alerts shall give concise, up-to-date information related to the observed exis-
tence of wind shear involving a headwind/tailwind change of 7.5m/s (15kt) 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.
7.4.4  Recommendation – Wind shear alerts should be updated at least every minute. The wind
shear alert should be cancelled as soon as the headwind/tailwind change falls below 7.5m/s
(15kt).

CHAPTER 8 – AERONAUTICAL CLIMATOLOGICAL INFORMATION

NOTE: Technical specifications related to this Chapter are given in Appendix 7.

GENERAL PROVISIONS

NOTE: In cases where it is impracticable to meet the requirements for aeronautical climatological
information on a national basis, the collection, processing and storage of observational data may
be affected through computer facilities available for international use, and the responsibility for the
preparation of required aeronautical climatological information may be delegated by agreement
between the meteorological authorities concerned.
8.1.1  Aeronautical climatological information required for the planning of flight operations shall
be prepared in the form of aerodrome climatological tables and aerodrome climatological summa-
ries. Such information shall be supplied to aeronautical users as agreed between the meteorologi-
cal authority and the user concerned.
NOTE: Climatological data required for aerodrome planning purposes are set out in Annex 14,
Volume I, 3.1.4.
8.1.2  Recommendation – Aeronautical climatological information should normally be based on
observations made over a period of at least 5 years and the period should be indicated in the
information supplied.
8.1.3  Recommendation – Climatological data related to sites for new aerodromes and to addi-
tional runways at existing aerodromes should be collected starting as early as possible before
commissioning of those aerodromes or runways.

AERODROME CLIMATOLOGICAL TABLES

Recommendation – Each Contracting State should made arrangements for collecting and retain-
ing the necessary observational data and have the capability:

8.1

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a. to prepare aerodrome climatological tables for each regular and alternate international aero-

drome within its territory; and

b. to make available such climatological tables to an aeronautical user within a time period as

agreed between the meteorological authority and the user concerned.

AERODROME CLIMATOLOGICAL SUMMARIES

Recommendation – Aerodrome climatological summaries should follow the procedures prescri-
bed by the World Meteorological Organization (WMO). Where computer facilities are available to
store, process and retrieve the information, the summaries should be published, or otherwise
made available to aeronautical users on request. Where such computer facilities are not availa-
ble, the summaries should be prepared using the models specified by WMO, and should be pub-
lished and kept up to date as necessary.

COPIES OF METEOROLOGICAL OBSERVATIONAL DATA

Each meteorological authority, on request and to the extent practicable, shall make available to
any other meteorological authority, to operators and to others concerned with the application of
meteorology to international air navigation, meteorological observational data required for
research, investigation or operational analysis.

CHAPTER 9 – SERVICE FOR OPERATORS AND FLIGHT CREW

MEMBERS

NOTE: Technical specifications and detailed criteria related to this Chapter are given in Appendix
8 (not herein published).

GENERAL PROVISIONS

9.1.1 Meteorological information shall be supplied to operators and flight crew members for:

a. pre-flight planning by operators;
b. in-flight replanning by operators using centralized operational control of flight operations;

c. use by flight crew members before departure; and

d. aircraft in flight.

9.1.2 Meteorological information supplied to operators and flight crew members shall cover the
flight in respect of time, altitude and geographical extent. Accordingly, the information shall relate
to appropriate fixed times, or periods of time, and shall extent to the aerodrome of intended land-
ing, also covering the meteorological conditions expected between the aerodrome of intended
landing and alternate aerodromes designated by the operator.
9.1.3 Meteorological information supplied to operators and flight crew members shall be up to
date and include the following information, as agreed between the meteorological authority and
the operators concerned:

a. forecasts of:

1. upper wind and upper-air temperature;

8.3

8.4

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2. upper-air humidity;
3. geopotential altitude of flight levels;
4. flight level and temperature of tropopause;
5. direction, speed and flight level of maximum wind;
6. SIGWX phenomena; and
7. cumulonimbus clouds, icing and turbulence;

NOTE 1: Forecasts of upper-air humidity and geopotential altitude of flight levels are used
only in automatic flight planning and need not be displayed.
NOTE 2: Forecasts of cumulonimbus clouds, icing and turbulence are intended to be pro-
cessed and, if necessary, visualized according to the specific thresholds relevant to user
operations.

b. METAR or SPECI (including trend forecasts as issued in accordance with regional air navi-

gation agreement) for the aerodromes of departure and intended landing, and for take-off,
en-route and destination alternate aerodromes;

c. TAF or amended TAF for the aerodromes of departure and intended landing, and for take-

off, en-route and destination alternate aerodromes;

d. forecasts for take-off;
e. SIGMET information and appropriate special air-reports relevant to the whole route;

NOTE: Appropriate special air-reports will be those not already used in the preparation of
SIGMET.

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

g. as determined by regional air navigation agreement, GAMET area forecast and/or area fore-

casts for low-level flights in chart form prepared in support of the issuance of AIRMET infor-
mation, and AIRMET information for low-level flights relevant to the whole route;

h. aerodrome warnings for the local aerodrome;

i. meteorological satellite images;
j. ground-based weather radar information; and

k. space weather advisory information relevant to the whole route.

9.1.4 Forecasts listed under 9.1.3 a) shall be generated from the digital forecasts provided by
the WAFCs whenever these forecasts cover the intended flight path in respect of time, altitude
and geographical extent, unless otherwise agreed between the meteorological authority and the
operator concerned.
9.1.5 When forecasts are identified as being originated by the WAFCs, no modifications shall be
made to their meteorological content.

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9.1.6  Charts generated from the digital forecasts provided by the WAFCs shall be made availa-
ble, as required by operators, for fixed areas of coverage as shown in Appendix 8, Figures A8-1,
A8-2 and A8-3 (not published herein).
9.1.7  When forecasts of upper wind and upper-air temperature listed under 9.1.3 a) 1) are sup-
plied in chart form, they shall be fixed time prognostic charts for flight levels as specified in
Appendix 2, 1.2.2 a). When forecasts of SIGWX phenomena listed under 9.1.3 a) 6) are supplied
in chart form, they shall be fixed time prognostic charts for an atmospheric layer limited by flight
levels as specified in Appendix 2, 1.3.2 and Appendix 5, 4.3.2.
9.1.8  The forecasts of upper wind and upper-air temperature and of SIGWX phenomena above
flight level 100 requested for pre-flight planning and in-flight replanning by the operator shall be
supplied as soon as they become available, but not later than 3 hours before departure. Other
meteorological information requested for pre-flight planning and in-flight replanning by the opera-
tor shall be supplied as soon as is practicable.
9.1.9  Where necessary, the meteorological authority of the State providing service for operators
and flight crew members shall initiate coordinating action with the meteorological authorities of
other States with a view to obtaining from them reports and/or forecasts required.
9.1.10  Meteorological information shall be supplied to operators and flight crew members at the
location to be determined by the meteorological authority, after consultation with the operators
and at the time agreed between the aerodrome meteorological office and the operator concerned.
The service for pre-flight planning shall be confined to flights originating within the territory of the
State concerned. At an aerodrome without an aerodrome meteorological office at the aerodrome,
arrangements for the supply of meteorological information shall be as agreed upon between the
meteorological authority and the operator concerned.

BRIEFING, CONSULTATION AND DISPLAY

NOTE: The requirements for the use of automated pre-flight information systems in providing
briefing, consultation and display are given in 9.4.
9.2.1  Briefing and/or consultation shall be provided, on request, to flight crew members and/or
other flight operations personnel. Its purpose shall be to supply the latest available information on
existing and expected meteorological conditions along the route to be flown, at the aerodrome of
intended landing, alternate aerodromes and other aerodromes as relevant, either to explain and
amplify the information contained in the flight documentation or, if so agreed between the mete-
orological authority and the operator concerned, in lieu of flight documentation.
9.2.2  Meteorological information used for briefing, consultation and display shall include any or
all of the information listed in 9.1.3.
9.2.3  If the aerodrome meteorological office expresses an opinion on the development of the
meteorological conditions at an aerodrome which differs appreciably from the aerodrome forecast
included in the flight documentation, the attention of flight crew members shall be drawn to the
divergence. The portion of the briefing dealing with the divergence shall be recorded at the time of
briefing and this record shall be made available to the operator.

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9.2.4 The required briefing, consultation, display and/or flight documentation shall normally be
provided by the aerodrome meteorological office associated with the aerodrome of departure. At
an aerodrome where these services are not available, arrangements to meet the requirements of
flight crew members shall be as agreed between the meteorological authority and the operator
concerned. In exceptional circumstances, such as an undue delay, the aerodrome meteorological
office associated with the aerodrome shall provide or, if that is not practicable, arrange for the pro-
vision of a new briefing, consultation and/or flight documentation as necessary.
9.2.5 Recommendation – The flight crew member or other flight operations personnel for whom
briefing, consultation and/or flight documentation has been requested should visit the aerodrome
meteorological office at the time agreed between the aerodrome meteorological office and the
operator concerned. Where local circumstances at an aerodrome make personal briefing or con-
sultation impracticable, the aerodrome meteorological office should provide those services by tel-
ephone or other suitable telecommunication facilities.

FLIGHT DOCUMENTATION

NOTE: The requirements for the use of automated pre-flight information systems in providing
flight documentation are given in 9.4.
9.3.1  Flight documentation to be made available shall comprise information listed under 9.1.3 a)
1) and 6), b), c), e), f) and, if appropriate, g) and k). However, flight documentation for flights of
two hours' duration or less, after a short stop or turnaround, shall be limited to the information
operationally needed, but in all cases the flight documentation shall at least comprise information
on 9.1.3 b), c), e), f) and, if appropriate, g) and k).
9.3.2  Whenever it becomes apparent that the meteorological information to be included in the
flight documentation will differ materially from that made available for pre-flight planning and in-
flight re-planning, the operator shall be advised immediately and, if practicable, be supplied with
the revised information as agreed between the operator and the aerodrome meteorological office
concerned.
9.3.3  Recommendation – In cases where a need for amendment arises after the flight docu-
mentation has been supplied, and before take-off of the aircraft, the aerodrome meteorological
office should, as agreed locally, issue the necessary amendment or updated information to the
operator or to the local air traffic services unit, for transmission to the aircraft.
9.3.4  The meteorological authority shall retain information supplied to flight crew members,
either as printed copies or in computer files, for a period of at least 30 days from the date of issue.
This 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.

AUTOMATED PRE-FLIGHT INFORMATION SYSTEMS FOR BRIEFING,

CONSULTATION, FLIGHT PLANNING AND FLIGHT DOCUMENTATION

9.4.1 Where the meteorological authority uses automated pre-flight information systems to
supply and display meteorological information to operators and flight crew members for self-brief-
ing, flight planning and flight documentation purposes, the information supplied and displayed
shall comply with the relevant provisions in 9.1 to 9.3 inclusive.

9.3

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9.4.2 Recommendation – Automated pre-flight information systems providing for a harmonized,
common point of access to meteorological information and aeronautical information services infor-
mation by operators, flight crew members and other aeronautical personnel concerned should be
as agreed between the meteorological authority and the civil aviation authority or the agency to
which the authority to provide service has been delegated in accordance with Annex 15, 2.1.1 c).
NOTE: The meteorological and aeronautical information services information concerned is speci-
fied in 9.1 to 9.3 and Appendix 8 (not published herein).
9.4.3 Where automated pre-flight information systems are used to provide a harmonized,
common point of access to meteorological information and aeronautical information services infor-
mation by operators, flight crew members and other aeronautical personnel concerned, the mete-
orological authority concerned shall remain responsible for the quality control and quality manage-
ment if meteorological information by means of such systems in accordance with Chapter 2,
2.2.2.
NOTE: The responsibilities relating to aeronautical information services information and the qual-
ity assurance of the information is given in Annex 15, Chapter 1, 2 and 3.

INFORMATION FOR AIRCRAFT IN FLIGHT

9.5.1  Meteorological information for use by aircraft in flight shall be supplied by an aerodrome
meteorological office or meteorological watch office to its associated air traffic services unit and
through D-VOLMET or VOLMET broadcasts as determined by regional air navigation agreement.
Meteorological information for planning by the operator for aircraft in flight shall be supplied on
request, as agreed between the meteorological authority or authorities and the operator con-
cerned.
9.5.2  Meteorological information for use by aircraft in flight shall be supplied to air traffic services
units in accordance with specifications of Chapter 10.
9.5.3  Meteorological information shall be supplied through D-VOLMET or VOLMET broadcast in
accordance with the specifications of Chapter 11.

CHAPTER 10 – INFORMATION FOR AIR TRAFFIC SERVICES,

SEARCH AND RESCUE SERVICES AND AERONAUTICAL

INFORMATION SERVICES

NOTE: Technical specifications related to this Chapter are given in Appendix 9 (not published
herein).

INFORMATION FOR AIR TRAFFIC SERVICES UNITS

10.1.1 The meteorological authority shall designate an aerodrome meteorological office or mete-
orological watch office to be associated with each air traffic services unit. The associated aero-
drome meteorological office or meteorological watch office shall, after coordination with air traffic
services unit, supply, or arrange for the supply of, up-to-date meteorological information to the
unit necessary for the conduct of its functions.

9.5

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10.1.2  Recommendation – An aerodrome meteorological office should be associated with an
aerodrome control tower or approach control unit for the provision of meteorological information.
10.1.3  A meteorological watch office shall be associated with a flight information center for the
provision of meteorological information.
10.1.4  Recommendation – Where, owing to local circumstances, it is convenient for the duties
of an associated aerodrome meteorological office or meteorological watch office to be shared
between two or more aerodrome meteorological offices or meteorological watch offices, the divi-
sion of responsibility should be determined by the meteorological authority in consultation with the
appropriate ATS authority.
10.1.5  Any meteorological information requested by an air traffic services unit in connection with
an aircraft emergency shall be supplied as rapidly as possible.

INFORMATION FOR SEARCH AND RESCUE SERVICES UNITS

Aerodrome meteorological offices or meteorological watch offices designated by the meteorologi-
cal authority in accordance with regional air navigation agreement shall supply search and rescue
services units with the meteorological information they require in a form established by mutual
agreement. For that purpose, the designated aerodrome meteorological office or meteorological
watch office shall maintain liaison with the search and rescue services unit throughout a search
and rescue operation.

INFORMATION FOR AERONAUTICAL INFORMATION SERVICES

UNITS

The meteorological authority, in coordination with the appropriate civil aviation authority, shall
arrange for the supply of up-to-date meteorological information to relevant aeronautical informa-
tion services units, as necessary, for the conduct of their functions.

CHAPTER 11 – REQUIREMENTS FOR AND USE OF

COMMUNICATIONS

NOTE 1: Technical specification and detailed criteria related to this Chapter are given in Appendix
10 (not published herein).
NOTE 2: It is recognized that it is for each Contracting State to decide upon its own internal
organization and responsibility for implementing the telecommunication facilities referred to in this
Chapter.

REQUIREMENTS FOR COMMUNICATIONS

11.1.1 Suitable telecommunications facilities shall be made available to permit aerodrome mete-
orological offices and, as necessary, aeronautical meteorological stations to supply the required
meteorological information to air traffic services units on the aerodromes for which those offices
and stations are responsible, and in particular to aerodrome control towers, approach control offi-
ces and the aeronautical telecommunications stations serving these aerodromes.
11.1.2 Suitable telecommunications facilities shall be made available to permit meteorological
watch offices to supply the required meteorological information to air traffic services and search

10.2

10.3

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and rescue services units in respect of the flight information regions, control areas and search
and rescue regions for which those offices are responsible, and in particular to flight information
centers, area control centers and rescue coordination centers and the associated aeronautical tel-
ecommunications stations.
11.1.3  Suitable telecommunication facilities shall be made available to permit world area fore-
cast centers to supply the required world area forecast system products to aerodrome meteoro-
logical offices, meteorological authorities and other users.
11.1.4  Telecommunication facilities between aerodrome meteorological offices and, as neces-
sary, aeronautical meteorological stations and aerodrome control towers or approach control units
shall permit communications by direct speech, the speed with which the communications can be
established being such that required points may normally be contacted within approximately 15
seconds.
11.1.5  Recommendation – Telecommunication facilities between aerodrome meteorological
offices or meteorological watch offices and flight information centers, area control centers, rescue
coordination centers and aeronautical telecommunication stations should permit:

a. communications by direct speech, the speed with which the communications can be estab-

lished being such that the required points may normally be contacted within approximately
15 seconds; and

b. printed communications, when a record is required by the recipient; the message transmit

time should not exceed 5 minutes.

NOTE: In 11.1.4 and 11.1.5 ‘approximately 15 seconds’ refers to telephony communications
involving switchboard operation and ‘5 minutes’ refer to printed communications involving retrans-
mission.
11.1.6  Recommendation – The telecommunication facilities required in accordance with 11.1.4
and 11.1.5 should be supplemented, as and where necessary, by other forms of visual or audio
communications, for example, closed-circuit television or separate information processing sys-
tems.
11.1.7  Recommendation – As agreed between the meteorological authority and the operators
concerned, provision should be made to enable operators to establish suitable telecommunica-
tions facilities for obtaining meteorological information from aerodrome meteorological offices or
other appropriate sources.
11.1.8  Suitable telecommunications facilities shall be made available to permit meteorological
offices to exchange operational meteorological information with other meteorological offices.
11.1.9  Recommendation – The telecommunications facilities used for the exchange of opera-
tional meteorological information should be the aeronautical fixed service or, for the exchange of
non-time critical operational meteorological information, the public Internet, subject to availability,
satisfactory operation and bilateral/multilateral and/or regional air navigation agreements.
NOTE 1: Aeronautical fixed service Internet-based services, operated by the world area forecast
centers, providing for global coverage are used to support the global exchanges of operational
meteorological information.

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NOTE 2: Guidance material on non-time-critical operational meteorological information and rele-
vant aspects of the public Internet is provided in the Guidelines on the Use of the Public Internet
for Aeronautical Applications (Doc 9855).

USE OF AERONAUTICAL FIXED SERVICE COMMUNICATIONS AND

THE PUBLIC INTERNET – METEOROLOGICAL BULLETINS

Meteorological bulletins containing operational meteorological information to be transmitted via
aeronautical fixed service or the public Internet shall be originated by the appropriate meteorologi-
cal office or aeronautical meteorological station.
NOTE: Meteorological bulletins containing operational meteorological information authorized for
transmission via aeronautical fixed service are listed in Annex 10, Volume II, Chapter 4, together
with the relevant priorities and priority indicators.

USE OF AERONAUTICAL FIXED SERVICE COMMUNICATIONS –

WORLD AREA FORECAST SYSTEM PRODUCTS

Recommendation – World area forecast system products in digital form should be transmitted
using binary data communication techniques. The method and channels used for dissemination of
the products should be as determined by regional air navigation agreement.

USE OF AERONAUTICAL MOBILE SERVICE COMMUNICATION

The content and format of meteorological information transmitted to aircraft and by aircraft shall
be consistent with the provisions of this Annex.

USE OF AERONAUTICAL DATA LINK SERVICE – CONTENTS OF D-

VOLMET

D-VOLMET shall contain current METAR and SPECI together with trend forecasts where availa-
ble, TAF and SIGMET, special air-reports not covered by SIGMET and, where available,
AIRMET.
NOTE: The requirement to provide METAR and SPECI may be met by the data link-flight informa-
tion service (D-FIS) application entitled ‘Data link-aerodrome routine meteorological report (D-
METAR) service’; the requirement to provide TAF may be met by the D-FIS application entitled
‘Data link-aerodrome forecast (D-TAF) service’; and the requirement to provide SIGMET and
AIRMET messages may be met by the D-FIS application entitled ‘Data link-SIGMET (D-SIGMET)
service’. The details of these data link services are specified in the Manual of Air Traffic Services
Data Link Applications (Doc 9694).

USE OF AERONAUTICAL BROADCAST SERVICE – CONTENTS OF

VOLMET BROADCASTS

11.6.1 Continuous VOLMET broadcasts, normally on very high frequencies (VHF) shall contain
current METAR and SPECI, together with trend forecasts where available.
11.6.2 Scheduled VOLMET broadcasts, normally on high frequencies (HF), shall contain current
METAR and SPECI, together with trend forecasts where available and, where so determined by
regional air navigation agreement, TAF and SIGMET.

11.2

11.3

11.4

11.5

11.6

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Appendix 1. Flight Documentation – Model Charts and Forms

MODEL A

OPMET information

MODEL IS

Upper wind and temperature chart for standard isobaric surface
Example 1 - Arrows, feathers and pennants (Mercartor projection)
Example 2 - Arrows, feathers and pennants (Polar stereographic pro-
jection)

MODEL SWH

Significant weather chart (high level)
Example - Polar stereographic projection (showing the jet stream verti-
cal extent)

MODEL SWM

Significant weather chart (medium level)

MODEL SWL

Significant weather chart (low level)
Example 1
Example 2

MODEL TCG

Tropical cyclone advisory information in graphical format

MODEL VAG

Volcanic ash advisory information in graphical format

MODEL STC

SIGMET for tropical cyclone in graphical format