AusFlightSim - How To Interpret/Decode a METAR Report - The Aussie Flight Simulation Site for Enthusiasts Around the World!

A METAR report is an important piece of information used to describe ground weather conditions at an aerodrome. The word METAR is actually a French abbreviation, which translates to "aviation routine meteorological report". At first glance a METAR report can be a little daunting but once you understand the elements that make up the report it will all become clear.

For the purpose of this article we'll use the following report for Coffs Harbour Airport taken at 7:30 UTC on the 18th of April 2006:

METAR YSCH 180730Z 03011KT 9999 FEW035 SCT090 BKN110 22/17 Q1017

Elements of a METAR Report

Type

Location

Date/Time

AUTO

Wind

Visibility, Weather, Cloud
or CAVOK

Temp/Dew Pt

QNH

Supp Info

Remarks

Type: METAR - The first element is the type of report. There are a number of different aviation weather reports available that follow a similar format, these include:

METAR - Routine weather report taken hourly or half hourly.
SPECI - This report is used to identify special observations.
TTF METAR or TTF SPECI - These reports are used to identify METAR or SPECI with a three hour trend appended and are for locations that issue Trend Type Forecasts.

Location: YSCH - This element specifies the ICAO code for the aerodrome at which the report has been made, in this case Coffs Harbour.

Date/Time: 180730Z - This is the origination date/time given in UTC using a six figure group followed by the abbreviation Z. In this example the report was taken on the 18th day of the month at 7:30am UTC.

AUTO: This element is not present in our example report. It will however appear for reports where automated observations have been made for visibility, present weather, and cloud.

Wind: 03011KT - This element represents current wind conditions. The first three digits represent the bearing from which the wind is travelling, followed by a further two digits indicating wind speed in knots. When winds are calm it will be reported as 00000KT. Wind direction can also be reported as VRB (variable) when a) they are light (3KT or less) or b) when forecasting a direction is not possible, for instance during a cyclone or the passage of a thunderstorm. Our example shows wind blowing from a direction of 030° at 11 knots.

Visibility, Weather, Cloud or CAVOK: 9999 FEW035 SCT090 BKN110 - This element expresses visibility, present weather and cloud height.

Visibility is expressed in metres. A value of 9999 indicates visibility greater than or equal to 10KM.

Present weather is indicated by up to three of the groups from the following table of abbreviations. Intensity of precipitation conditions is indicated by the use of a + or - symbol representing light or heavy conditions. The abbreviation VC before weather conditions indicates that the condition occurs in the vicinity (within 8KM).

CODE	TRANSLATION
	WEATHER DESCRIPTORS
BC	PATCHES (or PATCHES OF)
BL	BLOWING
DR	DRIFTING
FZ	FREEZING
MI	SHALLOW
SH	SHOWERS (or SHOWERS OF)
TS	THUNDERSTORMS (or THUNDERSTORMS WITH)
PR	AERODROME PARTIALLY COVERED BY FOG
	PHENOMENA
BR	MIST
DU	DUST
DS	DUST STORM
DZ	DRIZZLE
FC	FUNNEL CLOUDS
FG	FOG
FU	SMOKE
GR	HAIL
GS	SMALL HAIL PELLETS
HZ	HAZE
IC	ICE CRYSTALS (VERY SMALL ICE CRYSTALS IN SUSPENSION, ALSO KNOWN AS DIAMOND DUST)
PL	ICE PELLETS
PO	DUST DEVILS
RA	RAIN
SA	SAND
SG	SNOW GRAINS
SN	SNOW
SQ	SQUALLS
SS	SAND STORM
UP	UNKNOWN PRECIPITATION
VA	VOLCANIC ASH

Cloud coverage and height is expressed as the number of OCTAS or eighths of sky covered and in hundreds of feet. The following abbreviations are used to indicate the number of octas:

FEW = few = 1 to 2 OCTAS
SCT = scattered = 3 to 4 OCTAS
BKN = broken = 5 to 7 OCTAS
OVC = overcast = 8 OCTAS

Nil cloud is reported as SKC (sky clear).

The term CAVOK which means "Clouds and Visibility Okay", will be used in place of visibility, present weather and cloud when a) visibility is greater than or equal to 10KM b) no cloud below 5,000FT or below the highest minimum sector altitude and c) no significant weather.

The conditions in our example can be translated into the following statement:

Visibility greater than or equal to 10KM, 1 to 2 eights of could at a height of 3,500FT, 3 to 4 eights of cloud at a height of 9,000FT and 5 to 7 eights of cloud at a height of 11,000FT.

Temp/Dew Pt: 22/17 - This element is fairly self explanitory. The first value is the reported temperature and the second the dew point, both represented in degrees celsius.

QNH: Q1017 - This element is the altimeter setting to obtain elevation or altitude when on the ground. It is given in whole hectopascals using four digits prefixed by the letter Q.

Supp Info: Further information can be reported in this element to include a) reports of recent weather of significant operational importance or b) wind shear information for a take-off or landing runway.

Remarks: The remarks section is used to report further information such as rainfall, other significant conditions or trend type forecasts valid for up to three hours from the time of the observation.

From the information presented above we can explain our example METAR report with the following statement:

This is a report for Coffs Harbour Airport. The report was made at 07:30 UTC. The wind was blowing at a speed of 11 knots from a direction of 030°. The temperature was 22 °C, with a dew-point at 17 °C. The atmospheric pressure was 1017 hPa. There were a few clouds at a height of 3,500 feet, scattered clouds at a height of 9,000 feet, and broken clouds at a height of 11,000 feet. The overall visibility was greater than 10 kilometres.

As you can see, the elements of a METAR report provide very important information about the conditions at a particular aerodrome. Once you are familiar with the structure of the report you will be able to get a very good picutre of what to expect when flying into and out of any airfield in our simulated world.

You can get the latest METAR reports for many airports around the world from our Weather page.