1. AERODROME WEATHER REPORT CODES
(ACTUALS)
METARS

2. EGGY = Issuing authority, i.e. Bracknell
SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
BULLETIN HEADER
SA = METAR
UK02 = AREA CODE
EGGY = Issuing authority, i.e. Bracknell
231020Z : Bulletin Date = 23rd/Bulletin Issue Time = 1020 Zulu or UTC.
REPORT TYPE
METAR - A/D Actual weather. Compiled half-hourly or hourly while station open
SPECI - Aviation selected special weather report
(SPECI will not be disseminated by either OPMET in UK or MOTNE in Europe)
LOCATION INDICATOR
ICAO four-letter code e.g. EGSS = Stansted

3. Direction in degrees True (3 digits) to nearest 10°.
SAUK02 EGGY Z
METAR
EGSS Z 31015G30KT 1400SW 6000N R24L/P1500 SHRA FEW005 SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
WIND
Direction in degrees True (3 digits) to nearest 10°.
Wind speed (2 digits), usually 10 minute mean.
Followed by Units. KT, KMH or MPS.
E.g kt
Further 2 or 3 digits preceded by G gives gust speed when it exceeds 10 minute mean by 10 kt or more
E.g G30KT
Calm indicted by followed by units.
Variable wind direction given by VRB followed by speed and units.
If direction varies by 60° or more during10 minutes preceding the observation, the observed extremes are given in clockwise order.
E.g G30KT 280V350

4. HORIZONTAL VISIBILITY
SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
HORIZONTAL VISIBILITY
If no marked variation, the minimum given in metres.
For marked visibility variation the reported minimum is followed by one of 8 points of the compass.
E.g NE
If the minimum visibility is less than 1500m and the visibility in another direction is greater then 5000m then both are given.
E.g. 1400SW 6000N
Visibility of 10 km or more indicated by 9999
Visibility of less than 50 m indicated by 0000

5. RUNWAY VISUAL RANGE (RVR)
SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
RUNWAY VISUAL RANGE (RVR)
RVR group always prefixed by letter R followed by runway designator, followed by diagonal followed by touchdown RVR in metres.
Parallel runways indicated by letters L, R or C.
E.g. R24L/1100
When RVR is greater than the maximum reportable value then RVR figure preceded by letter P.
E.g. R24L/P1500
When the RVR is less than the minimum reportable value then the RVR figure preceded by the letter M.
E.g. R24L/M0050
Until further notice trends and significant variations in RVR will not be reported in the U.K.

6. SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
PRESENT WEATHER CODES
BR, HZ, FU, IC, DU and SA will not be reported when the visibility is >5000m

7. Shown by 6 character group. First 3 indicate cloud amount in OKTAS.
SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
CLOUD COVER
Shown by 6 character group.
First 3 indicate cloud amount in OKTAS.
FEW = 1 to 2 oktas
BKN = 5 to 7 oktas
SCT = 3 to 4 oktas.
OVC = 8 oktas
Last 3 indicate height of cloud base above a/d level
E.g: FEW018 = 1 to 2 oktas at 1800 feet above a/d level.
Only significant convective cloud identified.
CB = Cumulonimbus
TCU = Towering Cumulus.
E.g: SCT018CB
Sky obscured = VV///

8. CLOUD COVER REPORTING SEQUENCE
SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
CLOUD COVER REPORTING SEQUENCE
First group = Lowest layer of 1 okta or more
Second group = Next layer of 3 oktas or more
Third group = Next layer of 5 oktas or more.
Additional group = Significant convective cloud if not
already reported.
Cloud groups given in ascending order of height.
E.g: FEW005 SCT010 SCT018CB BKN025
If there is no cloud to report and CAVOK does not apply, then SKC (sky clear) reported

9. SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
CAVOK
Visibility, RVR, weather and cloud groups replaced by CAVOK when:
Visibility is 10 km or more.
No cloud below 5000 ft or
MSA, whichever is greater, and
No CB present
No significant weather phenomena at or in vicinity of a/d.

10. AIR TEMPERATURE AND DEW POINT
SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
AIR TEMPERATURE AND DEW POINT
Given in degrees Celcius.
Prefix M indicates negative value.
E.g: 10/03; /M01; 00/M00.

11. ALTIMETER SETTING (QNH)
SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
ALTIMETER SETTING (QNH)
QNH is rounded down to nearest whole millibar.
Reported as 4 figure group preceded by letter Q
E.g: Q0995
When reported in inches of mercury
Prefixed by letter A followed by 4 figure group
E.g: A3027 = inches of mercury.

12. SUPPLEMENTARY INFORMATION
SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
SUPPLEMENTARY INFORMATION
Consists of one or more of the following groups in sequence:
Recent weather.
Windshear.
Trend.
Runway state group.

13. Recent weather. E.g: RETS, REGR, RESHRA.
SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
Recent weather.
Operationally significant weather observed since last observation or during the past hour, whichever is shorter.
Prefixed by letters RE followed by appropriate weather codes.
E.g: RETS, REGR, RESHRA.

14. SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
Windshear
Inserted when windshear encountered along takeoff or approach paths below 1600 feet with reference to the runway.
Prefixed by the letters WS.
E.g: WS RWY20, WS ALL RWY.
Until further notice, UK aerodromes will not insert windshear groups.

15. SAUK02 EGGY Z
METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
TREND
This a forecast of significant changes in weather conditions during the two hours following the observation time.
Change Indicators
BECMG (becoming) TEMPO (temporary) followed by by a 4 figure time group (in hours and minutes UTC) preceded by one of the following, FM (from), TL(until) or AT (at).
Weather
Standard codes used. NOSIG used when no significant change in weather conditions expected.
E.g: BECMG FM G50KT;
TEMPO FM0630 TL SHRA.

16. RUNWAY STATE GROUP See handout . SAUK02 EGGY 231020Z METAR
EGSS Z G30KT SW 6000N R24L/P SHRA FEW SCT010CB BKN /03 Q0995 RETS WS RWY23 NOSIG =
RUNWAY STATE GROUP
See handout .

18. Aerodrome Forecast (TAF) Codes

19. FCUK31 EGGY
EGGW KT SCT010
BECMG RA BKN 012
TEMPO RADZ OVC004
FM G30KT SHRA BKN015CB=
HEADER:
Letters FC = 9 hour TAF (Issued every 3 hrs.)
FT = 18 hour TAF. (Issued every 6 hrs.)
UK31 = Forecast region.
EGGY = Issuing authority (Bracknell UK).
Date of issue = 30th.
Time of issue = 0900UTC.
EGGW = ICAO location identifier.
= Valid on date 30th between 1000 UTC and 1900 UTC.

20. Forecast Elements of a TAF.
FCUK31 EGGY
EGGW KT SCT010
BECMG RA BKN 012
TEMPO RADZ OVC004
FM G30KT SHRA BKN015CB=
Forecast Elements of a TAF.
Surface Wind
Visibility
Weather
Cloud
Probability
Significant changes
Amendments
Other Groups (not used on UK civil aerodromes).
Forecast temperature.
Airframe ice accretion.
Turbulence.

21. FCUK31 EGGY
EGGW KT SCT010
BECMG RA BKN 012
TEMPO RADZ OVC004
FM G30KT SHRA BKN015CB=
Surface Wind :
Same format as METAR. Variations in direction not forecast.
Horizontal Visibility :
Same format as METAR. Only the minimum expected forecast.
Weather:
If no significant weather expected - group omitted. If the weather after a change group ceases to be significant - abbreviation NSW (no significant weather) inserted.
Cloud :
When clear sky forecast - SKC (sky clear) inserted or CAVOK if criteria apply.
If SKC or CAVOK not appropriate then NSC (no significant cloud) used. Only CB cloud will be specified.

22. FCUK31 EGGY
EGGW KT SCT010
BECMG RA BKN 012
TEMPO RADZ OVC004
FM G30KT SHRA BKN015CB=
Significant Changes :
BECMG
followed by 4 figure time group indicates expected permanent change in items specified at regular or irregular rate. E.g. BECMG KT BKN010 FM
followed by 4 figure time group in hours and minutes UTC to indicate beginning of a self contained part of forecast.
All conditions before FM are superseded by conditions indicated after group.

23. Significant Changes Cont.:
FCUK31 EGGY
EGGW KT SCT010
BECMG RA BKN 012
TEMPO RADZ OVC004
FM G30KT SHRA BKN015CB=
Significant Changes Cont.:
TEMPO
followed by 4 figure time group indictes temporary variations in f/cast wx. Each occurrence lasting <1hour and in total less than half period specified.
PROB
followed by 30 or 40 as a % followed by 4 figure time group. E.g. PROB40 TEMPO 1416 TSRA.

24. FCUK31 EGGY
EGGW KT SCT010
BECMG RA BKN 012
TEMPO RADZ OVC004
FM G30KT SHRA BKN015CB=
Amendments :
AMD inserted after location identifier to indicate amended TAF. The new forecast covers remaining period of validity.
E.g: TAF EGZZ AMD Z
In an amended TAF bulletin, the indicators AAA or AAB and time of origin will appear in the header line beginning FC or FT.
AMD and date/time not normally used in UK TAF’s.

25. FCUK31 EGGY
EGGW KT SCT010
BECMG RA BKN 012
TEMPO RADZ OVC004
FM G30KT SHRA BKN015CB=
Other Groups:
Forecast Temperature
Airframe Ice Accretion
Turbulence
Not used at UK civil aerodromes, but are used in overseas and UK military TAF’s.
See handout for decodes.
Have not yet been asked in CAA exams.