UNDERSTANDING TAFS

This lesson will explain the Terminal Aerodrome Forecasts or TAF. Larger aerodromes often produce 9, 24 or 30-hour TAFs which give a good indication as to when a particular weather will be expected. They have a very similar structure to METAR with some slight differences.

    1. Report Type
    2. Location
    3. Date/Time of origin
    4. Validation time
    5. Wind
    6. Prevailing Visibility or CAVOK
    7. Significant Weather
    8. Cloud
    9. SignificantChange

1: The report type is TAF

TAF EGNM 070948Z 0709/0806 24012KT 9999 FEW045
PROB40 TEMPO 0709/0718 25015G25KT

2:  Location EGNM

TAF EGNM 070948Z 0709/0806 24012KT 9999 FEW045
PROB40 TEMPO 0709/0718 25015G25KT

3: Date and Time

07Date
0948ZTime

TAF EGNM 070948Z 0709/0806 24012KT 9999 FEW045
PROB40 TEMPO 0709/0718 25015G25KT

4: Validity Time:

This is the part that can often throw people off.

07Day08Day
09Hour06Hour

From the 7th at 0900 until the 8th at 0600, expect the following conditions.

On the second line, we have another Validity Time

07Day09Day
07Hour18Hour

Can you decode this?

0709/0718

TAF EGNM 070948Z 0709/0806 24012KT 9999 FEW045
PROB40 TEMPO 0709/0718 25015G25KT

5: Wind

240Wind Direction (Coming from)
12KTSpeed 10 Knots

Second line we have another wind section.

250Wind direction (Coming from)
15G25Speed 15 Knots Gusting 25

TAF EGNM 070948Z 0709/0806 24012KT 9999 FEW045
PROB40 TEMPO 0709/0718 25015G25KT

6: Prevailing visibility or CAVOK

Do you remember what 9999 represents?

0000Less than 50 metres999910 kilometres or more

7: Significant Weather.

In this case, none is mentioned if this was not the case they use the same codes as the METAR.

– LightNo qualifier = Moderate+ Heavy
BCPatchesBLBlowingBRMist
DSDust StormDUDustDZDrizzle
FCFunnel cloudFGFogFUSmoke
FZFreezingGRHail>5mmGSSmall Hail
HZ HazeICIce CrystalsMIShallow
PLIce PelletsPODust DevilsPRBanks
RARainSASandSHShowers
SGSnow GrainsSNSnowSQSqualls
SSSand StormsTSThunderstormsUPUnidentified
PrecipitationAuto Only
VAVolcanic AshVCIn vicinity  

8: Clouds

FEW045

0Clear
1-2FEWFew
3-4SCTScattered
5-7BKNBroken
8OVCOvercast

Between a few clouds 1-2 Oktas at 4500ft.

9: Significant changes.

PROB3030% probabilityPROB4040% probability
BECMGBecomingTEMPOTemporarily
GroupsTSRA BKN010CBThunderstorm with rain, broken
cumulonimbus at one thousand feet
FMFrom1416From fourteen hundred to sixteen
hundred

At the time of writing this here is the full TAF for EGNM

TAF EGNM 070948Z 0709/0806 24012KT 9999 FEW045
PROB40 TEMPO 0709/0718 25015G25KT
TEMPO 0714/0722 6000 SHRA RA
PROB30 TEMPO 0714/0722 3000 +SHRA +RA BKN014
PROB30 TEMPO 0722/0806 5000 RADZ BKN014