AERODROME WEATHER REPORT CODES (ACTUALS ) METARS

AERODROME AERODROME WEATHER REPORT WEATHER REPORT

CODESCODES(ACTUALS(ACTUALS))

METARSMETARS

SAUK02 EGGY 231020Z

METAR

EGSS 231020Z 31015G30KT 1400SW 6000N R24L/P1500 SHRA FEW005 SCT010CB BKN025 10/03 Q0995 RETS WS RWY23 NOSIG 88290592=

METAR - A/D Actual weather. Compiled half-hourly or

hourly while station open

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

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

SAUK02 EGGY 231020Z

METAR


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. 31015kt

•Further 2 or 3 digits preceded by G gives gust speed when it exceeds 10 minute mean by 10 kt or moreE.g. 31015G30KT

•Calm indicted by 00000 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. 31015G30KT 280V350

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. 4000 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 6000NVisibility of 10 km or more indicated by 9999

Visibility of less than 50 m indicated by 0000

SAUK02 EGGY 231020Z

METAR


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.

SAUK02 EGGY 231020Z

METAR


PRESENT WEATHER CODESQualifier Weather Phenomena

Intensity orProximity

Descriptor Precipitation Obscuration Other

MI - Shallow DZ – Drizzle BR - Mist

BC - Patches RA – Rain FG - Fog

PO – Dust/SandWhirls (Dust Devils)- Light

BL Blowing SN – Snow FU - Smoke SQ - Squalls

SH - Showers SG – Snow Grains VA – Volcanic Ash FC – Funnel Cloud(s) (tornado or water-spout)

TS - Thunderstorms IC – Ice Crystals (Diamond Dust)

DU – WidespreadDust

SS - Sandstorm

Moderate(no qualifier)

+ Heavy(Well developed inthe case of FC andPO)

FZ – Freezing (Super-cooled)

PE – Ice Pellets SA - Sand

GR – HailVCIn the vicinity (not atthe aerodrome butnot further awaythan approx 8 kmfrom the a/dperimeter.)

PR – Partial (covering part of aerodrome) GS – Small Hail

(<5 mmdiameter) and/or snow pellets

HZ - Haze

DS - Duststorm

BR, HZ, FU, IC, DU and SA will not be reported when the visibility is >5000m

SAUK02 EGGY 231020Z

METAR


CLOUD COVER

Shown by 6 character group.First 3 indicate cloud amount in OKTAS.

FEW = 1 to 2 oktasSCT = 3 to 4 oktas.

BKN = 5 to 7 oktas

Only significant convective cloud identified.

CB = Cumulonimbus

TCU = Towering Cumulus.

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.

E.g: SCT018CB

OVC = 8 oktas

Sky obscured = VV///

SAUK02 EGGY 231020Z

METAR


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.

Cloud groups given in ascending order of height.

E.g: FEW005 SCT010 SCT018CB BKN025

Additional group = Significant convective cloud if not already reported.

If there is no cloud to report and CAVOK does not apply, then SKC (sky clear) reported

SAUK02 EGGY 231020Z

METAR


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.

SAUK02 EGGY 231020Z

METAR


AIR TEMPERATURE AND DEW POINT

Given in degrees Celcius.

Prefix M indicates negative value.

E.g: 10/03; 01/M01; 00/M00.

SAUK02 EGGY 231020Z

METAR


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 = 30.27 inches of mercury.

SAUK02 EGGY 231020Z

METAR


SUPPLEMENTARY INFORMATION

Consists of one or more of the following groups in sequence:

Recent weather.

Windshear.

Trend.

Runway state group.

SAUK02 EGGY 231020Z

METAR


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.

SAUK02 EGGY 231020Z

METAR


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.

SAUK02 EGGY 231020Z

METAR


TRENDThis 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 FM1100 25035G50KT;

TEMPO FM0630 TL0830 3000 SHRA.

SAUK02 EGGY 231020Z

METAR


RUNWAY STATE GROUP

See handout .

SAUK02 EGGY 231020Z

METAR


Aerodrome Forecast Aerodrome Forecast (TAF) Codes(TAF) Codes

FCUK31 EGGY 300900EGGW 300900 301019 23010KT 9999 SCT010 BECMG 1114 6000 -RA BKN 012 TEMPO 1418 2000 RADZ OVC004 FM1800 30020G30KT 9999 -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.• 301019 = Valid on date 30th between 1000 UTC

and 1900 UTC.


• 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.

FCUK31 EGGY 300900EGGW 300900 301019 23010KT 9999 SCT010 BECMG 1114 6000 -RA BKN 012 TEMPO 1418 2000 RADZ OVC004 FM1800 30020G30KT 9999 -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.

FCUK31 EGGY 300900EGGW 300900 301019 23010KT 9999 SCT010 BECMG 1114 6000 -RA BKN 012 TEMPO 1418 2000 RADZ OVC004 FM1800 30020G30KT 9999 -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 2124 27017KT 4000 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.


• 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.


Amendments : AMD inserted after location identifier to indicate amended TAF. The new forecast covers remaining period of validity.

E.g: TAF EGZZ AMD 130820Z 130816

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.


Other Groups: Forecast TemperatureAirframe 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.

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AERODROME WEATHER REPORT CODES (ACTUALS ) METARS