MET.OR.200 Meteorological reports and other information

OBSERVATIONS AND REPORTS The observations form the basis for the preparation of reports. At aerodromes, the routine observations are supplemented by special observations whenever specified changes occur in respect of surface wind, visibility, runway visual range, present weather, clouds and/or air temperature.

ROUTINE OBSERVATIONS Aeronautical meteorological stations should make routine observations throughout the 24 hours of each day or as determined by the competent authority.

LOCAL SPECIAL REPORTS Local special reports should be transmitted to local air traffic services units as soon as the specified conditions occur. By agreement between the aeronautical meteorological station and the appropriate ATS unit, local special reports are not required to be disseminated in respect of:

(a)any element for which there is in the local air traffic services unit a display corresponding to the one in the meteorological station, and where arrangements are in force for the use of this display to update information included in local routine reports and local special reports; and

(b)runway visual range, when all changes of one or more steps on the reporting scale in use are being reported to the local air traffic services unit by an observer on the aerodrome.

METAR At aerodromes that are not operational throughout the 24 hours, the issuance of a METAR should commence at least 3 hours prior to the aerodrome resuming operations, or as agreed between the meteorological services provider and the operators concerned to meet pre-flight and in-flight planning requirements for flights due to arrive at the aerodrome as soon as it is opened for use.

DISSEMINATION OF METAR METAR, and corrections thereto, should be disseminated to international OPMET databanks and to centres responsible for the operation of aeronautical fixed service Internet-based services.

DISSEMINATION OF METAR Procedures for disseminating METAR to users are described in ICAO EUR Doc 018 ‘EUR OPMET DATA MANAGEMENT HANDBOOK’.

SPECI Where required, SPECI should be issued whenever changes when the following criteria are met:

(a)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 or more;

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

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

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

(1)freezing precipitation;

(2)moderate or heavy precipitation, including showers thereof; and

(3)thunderstorm, with precipitation;

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

(1)freezing fog;

(2)thunderstorm, without precipitation;

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

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

(2)from BKN or OVC to SCT or less.

DISSEMINATION OF SPECI SPECI dissemination should be identical to METAR dissemination.

DISSEMINATION OF SPECI SPECI representing a deterioration of meteorological conditions should be disseminated immediately after the observation. SPECI representing a deterioration of one weather element and an improvement in another weather element should also be disseminated immediately after the observation and should then be treated as deterioration reports.

DISSEMINATION OF SPECI A SPECI representing an improvement in conditions should be disseminated only after the improvement has been maintained for 10 minutes; it should be amended before dissemination, if necessary, to indicate the conditions prevailing at the end of that 10-minute period.

DISSEMINATION OF SPECI Procedures for disseminating SPECI to users are described in ICAO EUR Doc 018 ‘EUR OPMET DATA MANAGEMENT HANDBOOK’.

VOLCANIC ACTIVITY REPORT The report of occurrence of pre-eruption volcanic activity, volcanic eruptions and volcanic ash clouds should be made in the format of a volcanic activity report comprising the following meteorological 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

(e)concise description of the 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.