METAR and TAF Decoding Charts..

Use the information below to guide you through the cryptic information

METAR  decode

CODE ELEMENT

EXAMPLE

DECODE

NOTES

1 Location

FAJS

Johannesburg

Station four-letter indicator

Date/Time

291020Z

29th day @ ten twenty Zulu

 

2 Wind

Wind direction/speed

31015G27KT

310 degrees, 15 knots, gusting 27 knots

Gust only given if >= 10KT greater than the mean. VRB = variable. 00000KT = calm.

Extreme direction variance

280V350

Varying between 280 and 350 degrees

Variation given in clockwise direction, but only when mean speed is greater than 3 KT.

3 Visibility

Minimum visibility

1400SW

1400 metres to south-west

0000 = 'less than 50 metres'

9999 = 'ten kilometres or more'.

Direction (given by eight-point compass) is appended to the minimum visibility when minimum visibility is <= 5000m and maximum is at least 50% greater than this. .

Maximum visibility

6000N

6000 meters to north

Given where minimum visibility < 1500 m and maximum > 5000 m.

4 RVR

 

R27R/1100

RVR, runway 27 right, 1100 metres

RVR tendency (U = increasing; D = decreasing;  may be added after figure e.g. R27R/1100D P1500 = more than 1500 m; M0050 = less than 50 m. Significant variations example : R24/0950V1100, i.e. varying between two values.

5 Present weather

 

+SHRA

+ Heavy

SH Shower and

RA Rain

+ = Heavy (well developed in the case of +FC and +PO);

 - = Light;

no qualifier = Moderate.

BC=Patches

BL=Blowing

BR=Mist

DR=Drifting

DS=Duststorm

DU=Dust

DZ=Drizzle

FC=Funnel cloud

FG=Fog

FU=Smoke

FZ=Freezing

GR=Hail (>5mm)

GS=Small hail or snow pellets

HZ=Haze

IC=Ice crystals

MI=Shallow

PL=Ice pellets

PO=Dust devils

PR=Banks

RA=Rain

SA=Sand

SH=Showers

SG=Snow grains

SN=Snow

SQ=Squalls

SS=Sandstorm

TS=Thunderstorm

VA=Volcanic ash

VC=In vicinity

 

 

 

6 Cloud

 

FEW005 BKN025 SCT010CB

Few at 500 ft,

Broken at 2500 ft

Scattered 1000 ft with CB

SKC=Sky clear (0 oktas), FEW='few' (1-2 oktas), SCT='Scattered' (3-4 oktas), BKN='Broken' (5-7 oktas), OVC='Overcast'.

There are only two cloud types reported; TCU=towering cumulus and CB=cumulonimbus.

7 CAVOK#

 

CAVOK

'cav-oh-kay'

Visibility greater or equal to 10 km, no cumulonimbus, no cloud below 5000 ft or highest MSA (greater) and no weather significant to aviation.

8 Temp and dew point

 

10/03

temperature 10 degrees C

dew point 03 degrees C

If dew point is missing, example would be reported as 10///.

9 QNH*

 

Q1020

QNH 1020 millibars

Q indicates QNH in millibars

10 Recent weather

 

RETS

'recent thunderstorm'

RE = Recent, weather codes given above. Up to three groups may be present.

11 Wind shear

 

WS RWY24

'wind shear runway two four'

Will not be reported at present for UK aerodromes.

12 Trend

 

BECMG FM1100 23035G50KT TEMPO FM0630 TL 0830 3000 SHRA

'becoming from 1100, 230 degrees 35 KT , max 50 KT, temporarily from 0630 until 0830, 3000 metres, Moderate rain shower's

BECMG=Becoming

TEMPO=Temporarily

NOSIG=No sig change

NSW=No sig weather

AT=At

FM=From

TL=Until

NSC=No sig cloud

 

Any of the wind forecast, visibility, weather or cloud groups may be used, and CAVOK. Multiple groups may be present.

 

 

TAF decode

CODE ELEMENT

EXAMPLE

DECODE

NOTES

1 Report type

 

TAF

'TAF'

Name for an aerodrome forecast

2 Location

 

FAJS

JOHANNES BURG'

Station four-letter ICAO indicator

3 Date/Time of origin

 

130500Z

13th day @ 500 Zulu time

 

4 Validity time

 

130716

Valid from 13th day 7H Zulu to 16H Zulu

UTC (Greenwich Mean Time)

5 Wind

 

31015G25KT

'310 degrees 15 gusting 25 knots

VRB = Variable; 00000KT = calm

6 Min visibility or CAVOK*

 

8000

8000 Meters

9999 = 10 km or more; 0000 = less than 50 metres

7 Significant weather

 

-SHRA

- Light

SH Showers and

RA Rain

See present weather table on METAR TOP for details;

NSW = No significant weather

8 Cloud

 

FEW005

SCT010

SCTO18CB BKN025

Few at 500 ft,

Scattered at 1000 ft,

Scattered cumulonimbus at 1800 ft.

Broken at 2500 ft

SKC = sky clear; FEW = 1-2 oktas; SCT = 3-4 oktas; BKN = 5-7 oktas; OVC = 8 oktas;

'///' will give forecast vertical visibility in hundred of feet)

NSC = no significant cloud (none below 5,000 feet and no CB)

CB will be the only cloud type specified

9 Significant changes

Probability

PROB30

'30% probability'

Normally only 30% or 40% probability will be used.

Time

1416

'from 14H to 16H Zulu time OR

Indicates beginning and end time of forecast period in Zulu time

Change indicator

BECMG 1416
FM 1400

becoming from 14H to 16H Zulu time OR
from 1400 Zulu time followed by

Also TEMPO = temporarily may be used

Met. groups

TSRA BKN010CB

TS Thunderstorm with

RA Rain,

Broken cumulonimbus at 1000f t

Met. group follows indicating a change in some or all of the elements forecast in the first part of the TAF