Airborne Aviation Decoding a TAF

What is a TAF?

A Terminal Area Forecast (TAF) is a statement of meteorological conditions expected for a specified period in the airspace within a radius of 5 NM of the aerodrome reference point.

At most major airports a Trend Type Forecast (TTF) is available with the METAR (see Decoding a METAR). This is a a statement of trend valid for three hours from the time the observation. When a TTF covers your period of operation this supercedes the TAF and must be used.


Decoding a TAF

A TAF is constructed as follows:

Terminal Area Forecast Format

Here is a typical Terminal Area Forecast (TAF) on a fair weather day:

METAR
TAF YSCN 062019Z 0622/0710
28015KT 9999 FEW035
FM070600 22007KT CAVOK
RMK T 22 18 16 14 Q 1017 1019 1019 1019
METAR


Below is a rather complicated Terminal Area Forecast (TAF) to demonstrate a number of variables:

METAR
TAF AMD YSCN 060457Z 0606/0624
23015G25KT 9999 SCT040
BECMG 0609/0611 18015KT 8000 -SHRA FEW015 OVC025
INTER 0612/0614 VRB30G45KT 2000 TSRA SCT040CB
TEMPO 0614/0616 15012KT 4000 +RA BKN010
FM061600 VRB03KT 9999 CAVOK
PROB30 0618/0622 0500 FG
RMK MOD TURB BLW 5000FT TILL 061000
T 14 11 10 10 Q 1010 1006 1004 1004
METAR


The TAF is decoded below:

TAF AMD YSCN 060457Z 0606/0624

TAF - Terminal Area Forecast
AMD - Amended since its original issue
YSCN - The location, Camden
060457Z - Issue date and time in 6 figure format (6th day of month, 0457 UTC)
0606/0624 - Validity period (6th day of month, 0600-2400 UTC)
23015G25KT 9999 SCT040

23015G25KT - Wind from 230° true, 15 kts gusting to 25 kts.
9999 - Visibility expressed in metres, 9999 indicates greater than 10km
SCT040 - "Scattered" cloud at 4000ft AGL (SCT is 3-4 OKTAS of a possible 8 OKTAS)
BECMG 0609/0611 18015KT 8000 -SHRA FEW015 OVC025

BECMG - Becoming, meaning the change will occur over the period specified
0609/0611 - Changes will occur between 0900-1100 UTC on the 6th
18015KT - Wind from 180° true at 15 kts
8000 - Visibility expressed in metres
-SHRA - Light (-) showers (SH) of rain (RA)
FEW015 - "Few" clouds at 1500 ft AGL (FEW is 1-2 OKTAS of a possible 8)
OVC025 - "Overcast" cloud at 2500 ft AGL (OVC is 8 OKTAS of a possible 8)
INTER 0612/0614 VRB30G45KT 2000 TSRA SCT040CB

INTER - Intermittent, changes expected to occur for periods of less than 30 minutes
0612/0614 - Change will occur between 1200-1400 UTC on the 6th
VRB30G45KT - Variable wind, 30 kts gusting to 45 kts
2000 - Visibility is 2000 metres
TSRA - Thunderstorm (TS) with rain (RA)
SCT040CB - "Scattered" cumulonimbus cloud at 4000 ft AGL (SCT is 3-4 OKTAS of a possible 8)
Note: Only cumulonimbus (CU) and towering cumulus (TCU) are identified in a TAF.
TEMPO 0614/0616 15012KT 4000 +RA BKN010

TEMPO - Temporary, changes expected to occur for periods of less than 60 minutes
0614/0616 - Change will occur between 1400-1600 UTC on the 6th
15012KT - Wind 150° true at 12 kts
4000 - Visibility is 4000 metres
+RA - Heavy (+) rain (RA)
BKN010 - "Broken" cloud at 1000 ft AGL (BKN is 5-7 OKTAS of a possible 8)
FM061600 VRB03KT 9999 CAVOK

FM061600 - From 1600 UTC on the 6th the conditions will change to ...
VRB03KT - Variable wind at 3 kts
CAVOK - Cloud and Visibility OK (9999 visibility, no cloud below A050, no significant "weather")
PROB30 0618/0622 0500 FG

PROB30 - 30% probability of the conditions existing
0618/0622 - Conditions to exist between 1800-2200 UTC on the 6th
0500 - Visibility in metres
FG - Fog, sometimes weather conditions will be expressed in plain text. (eg. "FOG")
RMK MOD TURB BLW 5000FT TILL 061000

RMK - Remarks
"Moderate turbulence below 5000 ft (AGL) until 1000 UTC on the 6th"
T 14 11 10 10 Q 1010 1006 1004 1004

T - The temperature in 3 hourly intervals from the start of the forecast period (0600, 0900, etc)
Q - The QNH in 3 hourly intervals from the start of the forecast period (0600, 0900, etc)


Codes and Translations

Listed are the common codes you may expect to see in Australia on a TAF, TTF or METAR. For a full list of codes refer to AIP GEN 3.5.

WX
TRANSLATION
SH
SHOWERS (or SHOWERS OF)
TS
THUNDERSTORMS (or THUNDERSTORMS WITH)
BR
MIST
DU
DUST
DS
DUST STORM
DZ
DRIZZLE
FG
FOG
FU
SMOKE
GR
HAIL
HZ
HAZE
PO
DUST DEVILS
RA
RAIN
SN
SNOW
NSW
NIL SIGNIFICANT WEATHER
CLOUD
TRANSLATION
FEW
1-2 OKTAS
SCT
3-4 OKTAS
BKN
5-7 OKTAS
OVC
8 OKTAS
CAVOK
CLOUD AND VISIBILITY OK (No cloud below 5,000, Visibility 10km+)
NCD
NIL CLOUD DETECTED (Used on METAR)
TAF
TRANSLATION
AMD
AMENDED AERODROME FORECAST
COR
CORRECTED AERODROME FORECAST
CNL
CANCELLED AERODROME FORECAST
NIL
NIL AERODROME FORECAST
PROV
PROVISIONAL AERODROME FORECAST

Intensity is indicated with precipitation, duststorms and sandstorms. In these cases the weather code is prefixed by the qualifier - for light and + for heavy. Moderate intensity is indicated by the absence of a prefix.

Often forecasts will include weather in plain text. As an example a TAF may list "LIGHT SHOWERS OF RAIN" rather than the codes -SHRA.


Obtaining a TAF

You can obtain a TAF through the following methods:


METAR and Aerodrome Weather Information Service (AWIS)

In addition to the aerodrome forecast your decision making can be aided by observations of conditions that exist at the aerodrome.

A METAR will be supplied when you request a TAF. This will show actual conditions that exist at the aerodrome. Additionally many aerodromes feature an Automatic Weather Information Service (AWIS) that provides information generated from the Automatic Weather Station (AWS) on a continuous basis.

AIP ERSA will contain details of an AWIS if available. For Camden (YSCN) the AWIS details are as follows:

  • Phone 02 4655 9248 (24 hours)
  • VHF 125.1 (Outside tower hours)

Analysing the METAR or AWIS and comparing it to the conditions expected in the forecast can provide you with a level of confidence or suspicion with respect to the accuracy of the forecast.


More Information

More detailed information on TAFs can be found in AIP GEN 3.5 para 3.
 

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This article was created 05-May-2010 and last updated 17-April-2014. Use of the information on this page is subject to the terms of use. Please report any errors to the webmaster.