#AIRPORT WEATHER INDICATOR CODE#

This may, however, be overruled temporarily by a “TEMPO” or “PROB” if applicable, according to the table on the next page. The prevailing weather conditions forecast in the initial part of the TAF should be fully applied with the exception of the mean wind and gusts (and crosswind) which should be applied in accordance with the policy in the column “BECMG AT” and “FM….” in the table on the next page. TAFs valid for less than 12 HRs should be issued every 3 HRs and those valid for 12 to 30 HRs every 6 HRs.įrom the start of the TAF validity period up to the time of applicability of the first subsequent “FM….” or “BECMG” or, if no “FM….” or “BECMG” is given, up to the end of the validity period of the TAF. The period of validity should not be less than 6 HRs, no more than 30 HRs. This forecast is not used for the first 6 hours of the 24-hour forecast. Probability Forecast The probability forecast is given percentage that describes the probability of thunderstorms and precipitation occurring in the coming hours. “Temporary” is used for temporary fluctuations of weather, expected to last for less than an hour.ġ0. “Becoming” is used when a gradual change in the weather is expected over a period of no more than 2 hours. “From” is used when a rapid and significant change, usually within an hour, is expected. This information may be shown as From (FM), Becoming (BECMG), and Temporary (TEMPO). Forecast Change Group For any significant weather change forecast to occur during the TAF time period, the expected conditions and time period are included in this group. Only cumulonimbus (CB) clouds are forecast in this portion of the TAF report as opposed to CBs and towering cumulus in the METAR.ĩ. Forecast Sky Condition Forecast sky con- ditions are given in the same manner as the METAR. If no significant weather is expected during the forecast time period, the denotation “NSW” will be included in the “becoming” or “temporary” weather groups.Ĩ. Forecast Significant Weather Weather phenomenon is coded in the TAF reports in the same format as the METAR. If the forecast is greater than 6 miles, it will be coded as “P6SM.”ħ. Forecast Visibility The forecast visibility is given in statute miles and may be in whole numbers or fractions. The last two digits state the windspeed in knots as denoted by the letters “KT.” Like the METAR, winds greater than 99 knots are given in three digits.Ħ. The first three indicate the direction of the wind in reference to true north.

Forecast Wind The wind direction and speed forecast are given in a five-digit number group. The first two numbers indicate the date, followed by the two-digit beginning time for the valid period, and the last two digits are the ending time.ĥ. Valid Period Date and Time The valid forecast time period is given by a six-digit number group. Time is always given in UTC as denoted by the Z following the number group.Ĥ.

#AIRPORT WEATHER INDICATOR CODE#

Date and Time of Origin Time and date of TAF origination is given in the six-number code with the first two being the date, the last four being the time. ICAO Station Identifier The station identifier is the same as that used in a METAR.ģ. Type of Report A TAF can be either a routine forecast (TAF) or an amended forecast (TAF AMD).Ģ. The terminal forecast includes the following information in sequential order:ġ. The TAF utilizes the same descriptors and abbreviations as used in the METAR report. Each TAF is valid for a 24-hour time period, and is updated four times a day at 0000Z, 0600Z, 1200Z, and 1800Z. TAF reports are usually given for larger airports. A terminal aerodrome forecast is a report established for the 5 statute mile radius around an airport.

Airport weather indicator