Everything you need to know about a METAR for Aviation

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Contents: 

  1. What is a METAR

  2. How to read a METAR

  3. Why is a METAR important

  4. How long is a METAR good for

  5. Other questions

 

What is a METAR

A METAR is one of many weather reports. 

It stands for METeorological reports – Aviation Routine Weather Reports. 

 

A METAR is an hourly surface observation of conditions observed at an airport. 

 

There are 2 types of METAR reports a routine METAR report that is transmitted every hour. And then there is a special weather report also known as a SPECI. This special report is given when there is an update to the regular METAR for rapidly changing weather conditions, aircraft mishaps, or other critical information

 

How to read/decode a METAR

There is a lot of information in a METAR so it can’t be written out in plain English, instead, it’s written out in a special format. It will always follow the same format. Once you know the format and what all the numbers and letters mean it will be easier to read and you will be reading it like a pro in no time. 

 

Here are two METAR’s that we will look at and decipher

  1. METAR KLIT 160053Z VRB04G18KT 10SM -RA BR FEW047 SCT100 BKN250 28/09 A2996 RMK AO2 LTG DSNT ALQDS PRESRR SLP144 WSHFT30 OCNL DSNT LTGIC ALQDS CB DSNT ALQDS MOV E T02780089

 

  1. METAR KSFO 160056Z 26013KT 10SM FEW015 BKN018 17/13 A2990 RMK AO2 SLP157

 

Type of Report

METAR KLIT 160053Z VRB04G18KT 10SM FEW047 -RA BR SCT100 BKN250 28/09 A2996 RMK AO2 LTG DSNT ALQDS PRESRR SLP144 WSHFT30 OCNL DSNT LTGIC ALQDS CB DSNT ALQDS MOV E T02780089

 

METAR KSFO 160056Z 26013KT 10SM FEW015 BKN018 17/13 A2990 RMK AO2 SLP157

 

The first thing is the type of report.  In both these cases it’s a METAR, if it was a special, it would say SPECI instead of METAR. So this is the regular hourly report. 

 

ICAO Station Identifier

METAR KLIT 160053Z VRB04G18KT 10SM -RA BR FEW047 SCT100 BKN250 28/09 A2996 RMK AO2 LTG DSNT ALQDS PRESRR SLP144 WSHFT30 OCNL DSNT LTGIC ALQDS CB DSNT ALQDS MOV E T02780089

 

METAR KSFO 160056Z 26013KT 10SM FEW015 BKN018 17/13 A2990 RMK AO2 SLP157

 

This is the 4-letter ICAO station identifier, in the US the 3-letter identifier is prefixed with the letter “k”. 

METAR #1 is for Little Rock, Arkansas and METAR #2 is for San Fransisco, California. 

 

Date and Time 

METAR KLIT 160053Z VRB04G18KT 10SM -RA BR FEW047 SCT100 BKN250 28/09 A2996 RMK AO2 LTG DSNT ALQDS PRESRR SLP144 WSHFT30 OCNL DSNT LTGIC ALQDS CB DSNT ALQDS MOV E T02780089

 

METAR KSFO 160056Z 26013KT 10SM FEW015 BKN018 17/13 A2990 RMK AO2 SLP157

 

6-digit date/time group with a Z at the end. The first 2 numbers are the date so in this case the 16th of October. Then the next two are the hour 00 and the final two are minutes 56. The Z is for Zulu time so depending on your time zone you have to do a little bit of time. 

 

It is issued usually at 55 minutes past the hour but can vary anywhere from 53~59 minutes past the hour. 

 

If like me you have trouble converting to and from Zulu time, check out this website.

Little Rock is currently -5 hours from Zulu as it’s daylight savings time This report was made on the 16th of October at 7:53 PM Central Time. 

 

San Francisco is currently -7 hours from Zulu as it’s daytime savings. This report was made on the 16th of October at 5:56 PM Pacific Time. 

 

 

Wind

METAR KLIT 160053Z VRB04G18KT 10SM -RA BR FEW047 SCT100 BKN250 28/09 A2996 RMK AO2 LTG DSNT ALQDS PRESRR SLP144 WSHFT30 OCNL DSNT LTGIC ALQDS CB DSNT ALQDS MOV E T02780089

 

METAR KSFO 160056Z 26013KT 10SM FEW015 BKN018 17/13 A2990 RMK AO2 SLP157

5-digit group (will be 6 if the speed is over 99 knots). The first 3 digits are the wind direction, in degrees referenced from true north.


NOTE: This is the direction that the wind is coming from. 

 

If the degrees are less than 100 like 90 it will have a 0 in the front like this 090. The last two digits is the average speed in knots. If it’s over 99 knots then it will be 3 digits.

 

If the wind is reported as 00000KT, that means the wind is calm. 

Little Rock has some letters VRB, which stands for variable meaning that the directions is coming from different directions at 4 knots and the G means that the wind gusts up to 18 knots.

San Francisco as the wind direction is coming from 260 @ 13 knots. 

 

Visibility

METAR KLIT 160053Z VRB04G18KT 10SM -RA BR FEW047 SCT100 BKN250 28/09 A2996 RMK AO2 LTG DSNT ALQDS PRESRR SLP144 WSHFT30 OCNL DSNT LTGIC ALQDS CB DSNT ALQDS MOV E T02780089

 

METAR KSFO 160056Z 26013KT 10SM FEW015 BKN018 17/13 A2990 RMK AO2 SLP157

 

This is the surface visibility in statute miles, sometimes it will be given in fractions it will usually always have the letters SM after it. 

 

Both Little Rock and San Francisco have 10SM visibility this is the most that will be reported at larger airports some smaller airports will have P6SM which means more than 6 statute miles. Either way, you are looking at great visibility. 

 

Weather Phenomena

METAR KLIT 160053Z VRB04G18KT 10SM -RA BR FEW047 SCT100 BKN250 28/09 A2996 RMK AO2 LTG DSNT ALQDS PRESRR SLP144 WSHFT30 OCNL DSNT LTGIC ALQDS CB DSNT ALQDS MOV E T02780089

 

METAR KSFO 160056Z 26013KT 10SM FEW015 BKN018 17/13 A2990 RMK AO2 SLP157

 

This section is usually broken down into two categories: qualifiers ad weather phenomena. It may or may not apply depending on the situation. 

 

For Little Rock, we have light rain and mist

In San Francisco, we don’t have anything. 

 

 Here are some other items you might see

 

Descriptors: These eight descriptors apply to the precipitation or obstructions to visibility

TSThunderstorms
DRLow Drifting
SHShowers
MIShallow
FZFreezing
BCPatches
BLBlowing
PRPartial

Precipitation Types

RARain
DZDrizzle
SNSnow
GRHail (1/4″ or greater)
GSSmall hail/snow pellets
PLIce pellets
SGSnow grains
ICIce crystals(diamond dust)
UPUnknown precipitation (automated stations only)

Obstructions to visibility: Other than precipitation, that reduce horizontal visibility

FGFog (visibility less than 5/8 mile)
HZHaze
FUSmoke
PYSpray
BRMist (visibility 5/8 – 6 miles)
SASand
DUDust
VAVolcanic Ash

Other:

SQSquall
SSSandstorm
DSDuststorm
PODust/sand whirls
FCFunnel cloud
+FCTornado/waterspout

Intensity

a denotes light, no symbol denotes moderate, and + denotes heavy

 

Sky Condition

METAR KLIT 160053Z VRB04G18KT 10SM -RA BR FEW047 SCT100 BKN250 28/09 A2996 RMK AO2 LTG DSNT ALQDS PRESRR SLP144 WSHFT30 OCNL DSNT LTGIC ALQDS CB DSNT ALQDS MOV E T02780089

 

METAR KSFO 160056Z 26013KT 10SM FEW015 BKN018 17/13 A2990 RMK AO2 SLP157

 

This will give us the cloud amount, the height (add 2 zeros) AGL,  and the type. 

 

CLearR

0/8

FEW

0/8 – 2/8

SCaTtered

⅜-4/8

BroKeN

⅝-7/8

OVerCast

8/8

 

There will be a TC or a CB sometimes after the clouds for the cloud types which stand for Towering Cumulus or Cumulonimbus. More than 1 layer may be reported.

 

Little Rock is reporting 3 layers. Few at 4700 AGL, Scattered at 10,000 AGL, and Broken at 250,000. 

San Francisco is reporting Few at 1500 AGL and Broken at 1800 AGL. 

 

Temperature/Dew Point

METAR KLIT 160053Z VRB04G18KT 10SM -RA BR FEW047 SCT100 BKN250 28/09 A2996 RMK AO2 LTG DSNT ALQDS PRESRR SLP144 WSHFT30 OCNL DSNT LTGIC ALQDS CB DSNT ALQDS MOV E T02780089

 

METAR KSFO 160056Z 26013KT 10SM FEW015 BKN018 17/13 A2990 RMK AO2 SLP157

 

2 digits for the temperature given in celsius and 2 digits for the dew point. They are separated by the /. If the temperature is below zero it will have an M in front of the number. 

 

Little Rock is 28 degrees Celsius with a dew point of 9

San Francisco is 17 degrees Celsius with a dew point of 13. (The small difference explains the clouds). 

 

Altimeter

METAR KLIT 160053Z VRB04G18KT 10SM -RA BR FEW047 SCT100 BKN250 28/09 A2996 RMK AO2 LTG DSNT ALQDS PRESRR SLP144 WSHFT30 OCNL DSNT LTGIC ALQDS CB DSNT ALQDS MOV E T02780089

 

METAR KSFO 160056Z 26013KT 10SM FEW015 BKN018 17/13 A2990 RMK AO2 SLP157

 

The 4-digit format always has the letter A in front of it. The decimal point is not represented but it is represented as tens, ones, tenths, and hundredths. 

 

Little Rock 29.96

San Francisco 29.90

 

Remarks

METAR KLIT 160053Z VRB04G18KT 10SM -RA BR FEW047 SCT100 BKN250 28/09 A2996 RMK AO2 LTG DSNT ALQDS PRESRR SLP144 WSHFT30 OCNL DSNT LTGIC ALQDS CB DSNT ALQDS MOV E T02780089

 

METAR KSFO 160056Z 26013KT 10SM FEW015 BKN018 17/13 A2990 RMK AO2 SLP157

 

Sometimes the information in this section is useful and sometimes it’s just gibberish that bored pilots like to quiz each other with. 

 

An important part of the remarks would be a $ at the end of the METAR, this means that the information may be unreliable as the station needs maintenance. 

 

Let’s look at the Little Rock remarks section

AO2 – This means that the stations has a precipitation discriminator, meaning that it can tell the difference between rain, snow, mist, etc. Which is how it was able to tell us that there was mist. 

 

LTG DSNT ALQDS – Lightning in the distance in all quadrants. Usually, you get the frequency, distance, and location. But it appears that it was everywhere last night. 

 

PRESRR – The pressure is rising rapidly

 

SLP144 – Sea Level Pressure 1014.4

 

WSHFT30 – Wind Shift at 0030Z

 

OCNL DSNT LTGIC ALQDS  – Occasional in-cloud lightning distant in all quadrants

 

CB DSNT ALQDS MOV E – Cumunolimbums clouds moving east in the distance in all quadrants

 

T02780089 – A more exact temperature and dewpoint is 27.8 degrees celsius and 08.9 celsius

 

What all this tells you is that thunderstorms are coming and you probably shouldn’t be out flying. 

 

San Francisco remarks

 

AO2 – This means that the stations has a precipitation discriminator, meaning that it can tell the difference between rain, snow, mist, etc. 

 

SLP157 – Sea Level Pressure of 1015.7


 

Why is a METAR important

 

Not only do you have to know how to read a METAR for your practical test and your written test but the information that you are given can really help you make important decisions about your upcoming flight. 

 

A Metar gives you a snapshot of the weather at the airport. It can be instrumental in helping you make a decision on making that go-no-go decision. After looking at the Little Rock Metar I would stop looking at the weather and sit back on the couch and not go flying. 

 

Looking at the San Francisco METAR I would go flying under an IFR flight plan if I was not coming back to San Francisco because that temperature dewpoint spread is only going to get smaller, meaning that the clouds are only going to get lower which means that my chances of getting back in would not be good. 


 

 

How long is a METAR good for

A metar is only good for an hour, UNLESS there is a SPECI or a correction issued then it is no longer valid. 


 

 

Why is there a V in the Wind 150V260?

If the wind direction varies by 60 degrees or more and speeds greater than 6 knots, a variable group consisting of the extremes of the wind direction separated by a “v” will follow the prevailing wind group. In this case, the wind was blowing from 150 to 260. 

 

 

 


What does PK WND mean?

When the peak wind exceeds 25 knots, “PK WND” will be included in the remarks along with the direction, speed, and time. It will look something like this PK WND 15045/1830. Meaning that the peak wind was from 150 at 45 knots and it happened at 1830. 

 


 

 

Where can I get a METAR?

You can get them on any aviation app like Foreflight, but you can get them for free at https://aviationweather.gov/metar

 

 

 


What if there is a symbol or letter I don’t understand on a METAR?

Aviation weather will decode the METARs for you but if you want a handy PDF from the FAA with a list of abbreviations and acronyms check this one out.


 

There you have it, more than you ever wanted to know about METARs. If you have any questions about METAR or any other weather chart feel free to post it in the comment or send me a message. I will be glad to answer them for you.

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