Sebastian Reinwand: /* METAR */

2020-03-31T19:57:21Z

METAR

Chris Wirowski at 22:37, 23 January 2012

2012-01-23T22:37:23Z

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Michael Rohrwasser: /* METAR */

2008-07-05T17:01:37Z

METAR

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== METAR ==
The word '''METAR''' comes from the French phrase "message d’observation météorologique régulière pour l’aviation". It is thought to be a contraction of the French words '''MÉT'''éorologique ("Weather") '''A'''viation '''R'''égulière ("Routine"). A METAR is a codified observation message indicating airfield weather conditions observed at a given time. Such a message is established every hour, even sometimes every 30 minutes or shorter due to fast and heavy weather changes which affects the traffic flow. 
Sample: 
LOWW 011220Z 33007KT 280V020 3000 R34/1500 +RASH FEW040 BKN058TCU 16/07 Q1014 RETS WS RWY34
34231091 BECMG -SHRA SCT030CB
 
=== Detailed explanation ===
1.) Location Identifier: '''LOWW''' 
The four-letter ICAO code of the observing location. 
 
2.) Day of Month/Zulu Time: '''011220Z''' 
 
3.) Wind: '''33007KT''' 
Wind direction (true heading), rounded to the nearest ten degrees and always expressed as three digits. Direction can be given as VRB if wind direction is variable and wind speed is at most 3 knots. 
plus 
average wind speed of last 10 minutes in knots. 
or 
maximum gust wind speed in knots. 
If it is calm, the wind is given as 00000KT. 
 
4.) Variable Wind Direction: '''280V020''' 
This field is used if the total variation of wind direction during the last 10 minutes is 60 degrees or more and wind speed is more than 3 knots. The direction extrema are given in clockwise order 
 
5.) Horizontal Visibility: '''3000''' 
Usually, only the minimum visibility is reported. If the minimum is less than 1500m and the maximum is over 5000m, the maximum visibility and its direction are indicated by a second visibility group following the minimum visibility. 
 
6.) RVR Runway Visual Range: '''R34/1500''' 
Runway designator and runway visibility in meters. 
 
7.) Significant Weather: '''+RASH''' 
Intensity is expressed by: + = heavy, - = light, ''nothing'' = moderate 
Proximity is described by: VC = ViCinity (within 8km) 
BC = Banc - fog bench
BL = Blowing
DR = Drifting
FZ = Freezing
MI = Mince - thin fog layer
SH = Shower
TS = Thunderstorm
DZ = Drizzle
GR = Grêle - hail (diameter > 5mm)
GS = Grêsil - hail (diameter < 5mm)
IC = Ice Crystal
PE = Ice Pellets
RA = Rain
SG = Snow Grains
SN = Snow
BR = Brume - mist (vis 1000 to 3000m)
DU = Dust
FG = Fog (vis < 1000m)
FU = Fumée - smoke (vis < 3000m)
HZ = Haze
SA = Sand
VA = Vulcanic Ashes
DS = Dust Storm
FC = Funnel Clouds
PO = Dust Spins
SQ = Squall
SS = Sand Storm
 
8.) Clouds and Ceiling: '''FEW040 BKN058TCU''' 
 
Cloud coverage: 
FEW = few - 1 to 2 octas
SCT = scattered - 3 to 4 octas
BKN = broken - 5 to 7 octas
OVC = overcast - 8 octas
Cloud types: 
CB = cumulunimbus
TCU = towering cumuli or cumulus congestus
Also common: 
SKC = Sky Clear (no clouds)
OVC/// = clouds covering the sky and which base is below aerodrome level
VV/// = sky not visible
VV002 = vertical visibility is 200ft
CAVOK = ceiling and visibility is OK (vis > 10km and SKC)
9.) Temperature and Dew Point: '''16/07''' 
The difference between temperature and dew pont is called "spread", the smaller the spread the higher the risk of precipitation. 
 
10.) Pressure, QNH (altimeter setting): '''Q1014''' 
QNH = 1014 hPa (hectopascals - 1hPa = 1mb - millibar) 
 
11.) Recent Weather: '''RETS''' 
Recent Thunderstorm 
Also: 
RERA = recent rain
RESN = recent snow
NOSIG = no significant change
12.) Wind Shear: '''WS RWY34''' 
Also: 
WS TKOF RWY 16 = windshear when taking of runway 16
WS LDG RWY 34 = windshear when landing at runway 34
WS ALL RWYS = windshear all runways
13.) Runway Status: '''34231091''' 
'''34''' = runway 34 
'''2''' = wet 
'''3''' = covering 26 to 50% of runway surface 
'''10''' = 10mm thick 
'''91''' = braking action poor 
Explaination: 
1st and 2nd figure = runway designator 
3rd figure = type of deposit on the runway 
0 = runway clean and dry
1 = damp
2 = wet
3 = frost
4 = snow
5 = wet snow
6 = slush
7 = ice
8 = compacted snow
9 = snow drift
/ = unknown, removal in progress
4th figure = percentage of runway contamination 
1 = less than 10%
2 = 11 to 25%
3 = 26 to 50%
4 = 51 to 100%
/ = unknown, removal in progress
5th and 6th figure = deposit thickness 
01 to 90 = millimeters
92 = 10cm
93 = 15cm
94 = 20cm
95 = 25cm
96 = 30cm
97 = 35cm
98 = 40cm
99 = unknown
// = unable to measure
7th and 8th figure = braking action 
01 to 90 = coefficient 0.01 to 0.90
or
91 = poor
92 = medium to poor
93 = medium
94 = medium to good
95 = good
99 = uncertain
// = unknown
14.) Trend: '''BECMG -SHRA SCT030CB''' 
Consists of following keywords and other METAR components: 
BECMG: becoming
TEMPO: temporarily
NOSIG: no significant change expected within 2 hours
AT: at
FM: from
TL: until
15.) Remarks: 
RMK followed by METAR components and miscellaneous abbreviations. 

== Links ==
*[[TAF]]

@@ Line 58: / Line 58: @@
    VV/// = sky not visible
    VV002 = vertical visibility is 200ft
-   CAVOK = ceiling and visibility is OK (vis &gt; 10km and SKC)
+   CAVOK = clouds and visibility is OK (vis &gt; 10km and NSC)
 .) Temperature and Dew Point: '''16/07'''<br> The difference between temperature and dew pont is called "spread", the smaller the spread the higher the risk of precipitation.<br> <br> 10.) Pressure, QNH (altimeter setting): '''Q1014'''<br> QNH = 1014 hPa (hectopascals - 1hPa = 1mb - millibar)<br> <br> 11.) Recent Weather: '''RETS'''<br> Recent Thunderstorm<br> Also:<br>
@@ Line 128: / Line 128: @@
    TL: until
 .) Remarks:<br> RMK followed by METAR components and miscellaneous abbreviations.<br>
 == Links  ==

METAR - Revision history

Sebastian Reinwand: /* METAR */

Chris Wirowski at 22:37, 23 January 2012

Michael Rohrwasser: /* METAR */