TAF Code Breakdown
DECODING WEATHER FORECASTS
The following is an example AFW TAF for Ft. Bragg with
explanations and definitions of the code format.
Forecast
KFBG TAF RTD 021111 18010KT 8000 BR SCT040 BKN250 QNH3010INS 510003
BECMG 1314 22012G18KT 9999 VCTS SCT040 BKN250 QNH3008INS
TEMPO 1718 23015G25KT 4800 TSRA BKN015CB OVC050
BECMG 2223 22012G18KT 8000 SHRA BR BKN030CB OVC100 QNH3000INS
T25/21Z T18/11Z
| KFBG |
Location identifier. This four letter identifier states the
location that the forecast is valid for. i.e BECMG states that
there's a gradual change in the weather between 1300Z and 1400Z. |
| TAF |
Message identifier of "TAF" (Terminal Airdrome Forecast). |
| RTD |
Modifier (AMD, COR, AMD COR, RTD).
AMD - Forecast was
amended.
COR - Forecast
was corrected.
AMD COR - Forecast
was initially amended then corrected.
RTD - Forecast was
transmitted late. |
| 021111 |
Valid Period. The valid period consists of the current date and
the 24 hr. period of the forecast. |
| 18010KT |
Surface Wind Direction, Speed, and Gust if any.
180.
Forecast true wind direction (from which wind is blowing) to the nearest
10 degrees.
10. Mean
forecast wind speed in whole knots (KT) which is the unit indicator
for speed. |
| 8000 |
Forecast prevailing visibility in meters. Whenever visibility is
forecast to be 9000 or less, the weather phenomena, obscuration to
visibility, or vicinity remark will be included. |
| BR |
Forecast weather phenomena, obstruction
to visibility, or vicinity remark which will cause visibility to
decrease or weather that is expected within 5 to 10 miles (vicinity e.g.
VCTS). |
| SCT040 |
Cloud layer group. This group has two sections:
Cloud amount: SKC (no
clouds), FEW (TRACE to 2 oktas), SCT (3 to 4 oktas), BKN (5 to 7 oktas),
and OVC (8 oktas).
Cloud heights: Forecast
height (AGL) of cloud base to nearest 100 feet from surface (040; ten
thousands, thousands, and hundreds of feet). |
| QNH3010INS |
Minimum altimeter setting. (30.10 inches) |
| 620046 |
Icing Group
6. Icing Indicator.
2. Type of Icing forecast.
004. Height of the icing layer base in hundreds of feet AGL.
6. Thickness of the icing layer in thousands of
feet AGL. |
| 510003 |
Turbulence Group
5. Turbulence Indicator.
1. Turbulence type and intensity.
000. Height of the turbulence layer base in hundreds of feet AGL.
3. Thickness of the turbulence layer in
thousands of feet AGL. |
T25/21Z
T18/11Z |
The Forecast Surface Temperature Group.
T - an indicator, meaning temperature
25 - the forecast max/min temperature in whole degrees
Celsius (C)
21Z - the valid time to the nearest whole hour UTC of the
temperature forecast and Z is an abbreviated symbol meaning Universal
Coordinated Time (UTC) |
|
INTENSITY
|
DESCRIPTOR
|
PRECIPITATION
|
OBSCURATION
|
OTHER
|
|
- Light
|
MI Shallow
|
DZ Drizzle
|
BR Mist
|
PO Dust/Sand Whirls
|
|
Moderate
|
PR Partial
|
RA Rain
|
FG Fog
|
SQ Squalls
|
|
+ Heavy
|
BC Patches
|
SN Snow
|
FU Smoke
|
FC Funnel Cloud/Tornado
|
|
|
DR Drifting
|
SG Snow Grains
|
VA Volcanic Ash
|
SS Sandstorm
|
|
VC Vicinity
|
BL Blowing
|
IC Ice Crystals
|
DU Dust
|
DS Duststorm
|
|
|
SH Showers
|
PL Ice Pellets
|
SA Sand
|
|
|
TS Thunderstorm
|
GR Hail
|
HZ Haze
|
NSW No Significant Weather
|
|
FZ Freezing
|
GS Small Hail or Snow Pellets
|
PY Spray
|
|
AFW Icing "6 Group"
| Code Figure |
Type of Icing |
|
0 |
No Icing |
|
1 |
Light Icing (mixed) |
|
2 |
Light Icing in cloud (RIME) |
|
3 |
Light Icing in precipitation (clear) |
|
4 |
Moderate Icing (mixed) |
|
5 |
Moderate Icing in cloud (Rime) |
|
6 |
Moderate Icing in precipitation (clear) |
|
7 |
Severe Icing (mixed) |
|
8 |
Severe Icing in cloud (Rime) |
|
9 |
Severe Icing in precipitation (clear) |
AFW Turbulence "5 Group"
| Code Figure |
Turbulence Type & Intensity |
|
0 |
None |
|
1 |
Light Turbulence |
|
2 |
Moderate clear air Turbulence, occasional |
|
3 |
Moderate clear air Turbulence, frequent |
|
4 |
Moderate in cloud Turbulence, occasional |
|
5 |
Moderate in cloud Turbulence, frequent |
|
6 |
Severe clear air Turbulence, occasional |
|
7 |
Severe clear air Turbulence, frequent |
|
8 |
Severe in cloud Turbulence, occasional |
|
9 |
Severe in cloud Turbulence, frequent |
|
X |
Extreme Turbulence |
|
Occasional |
Occurring less than 1/3 of the time |
|