AIM Basic w/ Chg 1, 2, and 3 dtd 9-5-24

4/20/23

AIM

28024G36KT

. . wind two eight zero at two four gusts three six

3/4SM

. . . . . . . . visibility three fourths

+TSRA

. . . . . . . thunderstorms, heavy rain

BKN008

ceiling eight hundred broken

OVC020CB

. . . two thousand overcast cumulonimbus clouds

28/23

. . . . . . . . . temperature two eight, dew point two three

A3000

. . . . . . . . altimeter three zero zero zero

RMK

. . . . . . . . remarks

TSRAB24

. . . . . thunderstorm and rain began at two four

TS W MOV E

thunderstorm west moving east

c. Aerodrome Forecast (TAF).

A concise statement of the expected meteorological conditions at an airport

during a specified period. At most locations, TAFs have a 24 hour forecast period. However, TAFs for some

locations have a 30 hour forecast period. These forecast periods may be shorter in the case of an amended TAF.

TAFs use the same codes as METAR weather reports. They are scheduled four times daily for 24

−

hour periods

beginning at 0000Z, 0600Z, 1200Z, and 1800Z.
Forecast times in the TAF are depicted in two ways. The first is a 6

−

digit number to indicate a specific point in

time, consisting of a two

−

digit date, two

−

digit hour, and two

−

digit minute (such as issuance time or FM). The

second is a pair of four

−

digit numbers separated by a “/” to indicate a beginning and end for a period of time.

In this case, each four

−

digit pair consists of a two

−

digit date and a two

−

digit hour.

TAFs are issued in the following format:
TYPE OF REPORT/ICAO STATION IDENTIFIER/DATE AND TIME OF ORIGIN/VALID PERIOD DATE

AND TIME/FORECAST METEOROLOGICAL CONDITIONS

NOTE

−

The “/” above and in the following descriptions are for separation purposes in this publication and do not appear in the

actual TAFs.

TAF KORD 051130Z 0512/0618 14008KT 5SM BR BKN030

TEMPO 0513/0516 1 1/2SM BR

FM051600 16010KT P6SM SKC

FM052300 20013G20KT 4SM SHRA OVC020

PROB40 0600/0606 2SM TSRA OVC008CB

BECMG 0606/0608 21015KT P6SM NSW SCT040

TAF format observed in the above example:
TAF = type of report
KORD = ICAO station identifier
051130Z = date and time of origin (issuance time)
0512/0618 = valid period date and times
14008KT 5SM BR BKN030 = forecast meteorological conditions
Explanation of TAF elements:

1. Type of Report.

There are two types of TAF issuances, a routine forecast issuance (TAF) and an

amended forecast (TAF AMD). An amended TAF is issued when the current TAF no longer adequately describes

the on-going weather or the forecaster feels the TAF is not representative of the current or expected weather.

Corrected (COR) or delayed (RTD) TAFs are identified only in the communications header which precedes the

actual forecasts.

2. ICAO Station Identifier.

The TAF code uses ICAO 4

−

letter location identifiers as described in the

METAR section.

Meteorology

−