Metar

$Id: README,v 1.2 2005/06/23 07:07:18 kees-guest Exp $

METAR reports are meteorogical weather reports for aviation. Metar is a small program which downloads weather reports for user-specified stations and optionally decodes them into a human-readable format.

Currently, metar supports decoding date/time, wind, visibility, cloud layers, temperature, air pressure and weather phenomena, such as rain, fog, etc. Also, more work in the area of clouds need to be done, as support for Cumulus or Cumulunimbus is not yet decoded.

There is a distinct difference between European METAR reports and US Metar reports. A US METAR report typically looks like:

KJFK 141751Z 33017G22KT 10SM FEW050 02/M10 A3005 RMK AO2 SLP174 T00221100 10033 20017 51007

This METAR can be decoded as follows:

KJFK John F. Kennedy Airport, New York, New York, This is the ICAO identifier of the airport.

141751Z The report is of the 14th of the month, at 17:51Z (which is 12:51pm local time in New York in the winter.)

33017G22KT The wind is coming from the direction of 330 degrees (Northwest) at 17 knots, with wind gusts to 22 knots.

10SM Visibility at the ground is clear (10 statue miles or more)

FEW050 FEW clouds at 5000 feet. Few is METAR-speak for 2/8 cloud cover.

02/M10 The temperature is 2 degrees Celcius, with the dewpoint at -10C.

A3005 The altimeter setting (air pressure) is 30.05 inches Hg

RMK etc Remarks local to the field.

A European METAR report:

EHAM 141825Z 18010KT 2700 BR SCT003 BKN004 04/04 Q1024 BECMG BKN003

EHAM Amsterdam Schiphol Airport, The Netherlands.

141825Z The report is of the 14th of the month, at 18:25Z (which is 19:25 local time in Amsterdam in the winter.

18010KT The wind is coming from 180 degrees (due South) at 10 knots.

2700 Visibility at ground level is 2700 meters.

BR Mist (visibility at least 5/8 statue mile)

SCT003 Scattered clouds at 300 ft (SCT is 4/8 cover)

BKN004 Broken clouds at 400 ft (BKN is 5/8 through 7/8 cover)

04/04 Temperature 4 degrees C, dewpoint 4 C

Q1024 Air pressure at 1024 hPa

BECMG BKN003 Becoming BK003, cloud layer is changing to BKN at 300 ft.

The program currently supports the following command line paramters:

-d Decode METARs -h Show a short usage summary -v Be verbose

Currently recognized weather phenomena are:

Descriptors
	MI	Shallow
	BL	Blowing
	BC	Patches
	SH	Showers
	PR	Partial
	DR	Drifting
	TS	Thunderstorm
	FZ	Freezing
	VC Vicinity

Weather phenomena
	DZ	Drizzle
	IC	Ice Crystals
	UP	Unkniwn
	RA	Rain
	PL	Ice Pellets
	SN	Snow
	GR	Hail
	SG	Snow Grains
	GS	Small hail/snow pellets

Obscuration
	BR	Mist (or vis <= 5/8 sm)
	SA	Sand
	FU	Smoke
	HZ	Haze
	VA	Volcanic Ash
	PY	Spray
	DU	Widespread Dust

Other
	SQ	Squall
	FC	Funnel Cloud
	SS	Sand storm
	+FC	Tornado/Watersprout
	DS	Dust storm
	PO	Well developed dust/sand swirls

Metar sources and bug tracking are gracefully hosted by the Debian project. Please visit http://alioth.debian.org/projects/metar/ for more information.

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