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How to Decode METARs and TAFs Like a Pro

How to Decode METARs and TAFs Like a Pro

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Exclusive Tu<strong>to</strong>rial<br />

<strong>How</strong> <strong>to</strong> <strong>Decode</strong> <strong>METARs</strong> <strong>and</strong> <strong>TAFs</strong> <strong>Like</strong> a <strong>Pro</strong><br />

Chris Palmer Angle of Attack Avia<strong>to</strong>r90<br />

As I’m sure you already know, having the current weather observations <strong>and</strong> near<br />

future forecasts for any flight you do is important. For aircraft like airliners (MD11,<br />

747, 767) that have the capability <strong>to</strong> h<strong>and</strong>le most situations, this is pretty easy. But<br />

for aircraft that are single engine <strong>and</strong> lightly equipped for instrument conditions, this<br />

could be disastrous. With that said, METAR <strong>and</strong> <strong>TAFs</strong> are important for ALL pilots <strong>and</strong><br />

ALL aircraft.<br />

Let’s break this up in<strong>to</strong> the different types. Although <strong>METARs</strong> <strong>and</strong> <strong>TAFs</strong> read much<br />

the same, they show different things al<strong>to</strong>gether. The main difference being a METAR<br />

is the current observation, <strong>and</strong> a TAF is a forecast, or in other words, predicted<br />

weather in the near future.<br />

<strong>METARs</strong> mentioned a METAR is a current observation. This is au<strong>to</strong>matically generated<br />

by an on field reporting system which communicates with different outlets <strong>to</strong> give the<br />

pilots information, whether it be for planning purposes or if the pilots are on<br />

approach <strong>to</strong> l<strong>and</strong> at the airport.<br />

Keep in mind you won’t learn everything now, but you’ll have a good idea of what’s<br />

going on. Later we’ll share sources with you that can be a resource for you in<strong>to</strong> you<br />

have a great grasp on <strong>METARs</strong> <strong>and</strong> <strong>TAFs</strong>.<br />

Here is a simple METAR we will break down.


KSLC 192353Z 30004KT 10SM CLR 29/02 A3000 RMK AO2 SLP110<br />

T02940017 10306 20261 56014<br />

Location
<br />

KSLC is simply the airport of the observation, in ICAO (<strong>Pro</strong>nounced I-K-OH in one<br />

word) format.<br />

Date <strong>and</strong> Time<br />

192353Z is broken down in<strong>to</strong> 2 sections. The first 2 numbers are the date of the<br />

month. The next 5 digits are the four digit time <strong>and</strong> Z for Zulu. So, this METAR was<br />

given on the 19th day of the Month at 2353Z.<br />

Wind
<br />

30004KT is also broken in<strong>to</strong> two parts. The first three digits are the wind direction,<br />

<strong>and</strong> last two numbers is the windspeed in knots, noted by KT.<br />

Visibility<br />


10SM is the current visibility for the airport. This gets a bit for complicated when we<br />

get in instrument conditions. Generally, 10SM means it is completely clear <strong>and</strong><br />

visible. This may also be noted as P6SM which st<strong>and</strong>s for 6 statute miles <strong>and</strong> plus<br />

(beyond)<br />

Clouds<br />

CLR means the area is clear of clouds. As you can see, CLR is very easily translated<br />

in<strong>to</strong> what it needs <strong>to</strong> be. As a simmer or even a pilot, most abbreviations can be<br />

worked out very easily with just a little thought. With that said, other METAR<br />

abbreviations make no sense. For example, mist in the area is noted in a METAR by<br />

BR. Tell me how that makes sense.<br />

Temperature <strong>and</strong> Dewpoint
<br />

29/02 is first temperature in Celsius, followed by the dewpoint. A small Temperature<br />

<strong>and</strong> Dewpoint spread usually means that there will be more clouds in the area <strong>and</strong>/or<br />

less visibility.<br />

Barometric Pressure/Altimeter Setting<br />


A3000 is the altimeter setting <strong>to</strong> be used by the pilot. This is the current pressure for<br />

the airport. In addition, for those areas of the world that use Millibars, this will show<br />

more like Q1011 rather than A3000.<br />

RMK st<strong>and</strong>s for Remarks.


Station Type
<br />

AO2 is a particular type of weather reporting station that can ‘discriminate’ if there is<br />

precipitation or not. You won’t always see this in a METAR.<br />

Sea Level Pressure<br />

For those of you in the countries using millibars, SLP110 is the setting you’ll use, as<br />

we discussed before.<br />

Precise Temperature <strong>and</strong> Dewpoint
<br />

T02940017 notes our exact temperature <strong>and</strong> dewpoint. In this case, 29.4 <strong>and</strong> 1.7<br />

degrees Celsius, respectively.<br />

The last three sections are either jibberish or very advanced for this particular<br />

METAR. As a pilot you’ll eventually learn what is important for your observation <strong>and</strong><br />

what isn’t. By using the resources we provide at the end of this tu<strong>to</strong>rial, you’ll be<br />

able <strong>to</strong> find answers <strong>to</strong> most of your questions.<br />

Now for a more complex METAR<br />

EIDW 092507Z 24035G55KT 210V270 1700 +SHRA BKN007 OVC015CB<br />

08/07<br />

The first two sections need not be explained again.<br />

Winds
<br />

24035G55KT The winds are now much more interesting. The first part remains<br />

unchanged, <strong>and</strong> in this case we are looking at winds from 240 at 35 knots. The<br />

addon means that there are Gusts of 55 knots in the mix, although these are not<br />

sustained winds.<br />

The next chunk, 210V270, is also winds. This means that the winds are variable<br />

between 210 <strong>and</strong> 270 heading. 240, from the first chunk of winds, is the average.<br />

Visibility/RVR<br />

In this case, 1700 is shown for visibility. This is not 1700 statute miles. Rather, it’s<br />

1700 Meters. This means the visibility is quite low.<br />

In this case, you can see it’s around 1 SM visibility. (1700= somewhere just above<br />

1600, which is just under a mile above)


Precipitation<br />

Omitted if not used, but in this case we see +SHRA. This means, SH, showers, RA,<br />

rain, <strong>and</strong> plus, is heavy. So, we are looking at moderate rain showers.<br />

Clouds<br />


BKN007 notes a significant cloud layer. Simply add two 0’s on<strong>to</strong> this <strong>to</strong> get the<br />

altitude of the cloud layer. In this case, we have broken clouds, which can be just<br />

under overcast, at 700 feet.<br />

OVC015CB notes that we have overcast (near complete or complete coverage) at<br />

1500 feet. These clouds are CB, slang as Charlie Bravo, which is Cumulonimbus<br />

clouds. Why is this important <strong>to</strong> know Cumuloform clouds are most commonly<br />

known with thunders<strong>to</strong>rms. No one <strong>and</strong> no aircraft messes with a thunders<strong>to</strong>rm <strong>and</strong><br />

feels good about it!<br />

Temperature/Dewpoint
<br />

As mentioned before, a small spread between these two values will generally mean<br />

poor visibility. In this case, it is a perfect example.<br />

This does it for what we will teach you about <strong>METARs</strong>. Here are some great resources<br />

<strong>to</strong> go out <strong>and</strong> study on your own:<br />

Click HERE<br />

<strong>TAFs</strong>
<br />

TAF st<strong>and</strong>s for Terminal Aerodrome Forecast. What does Aerodrome mean! In this<br />

case, it doesn’t much matter. What you do need <strong>to</strong> know is that depending on<br />

location, these will be anywhere between 9 <strong>and</strong> 24 hour forecasts.<br />

<strong>TAFs</strong> look much the same as <strong>METARs</strong>, so most of it won’t need <strong>to</strong> be covered. But,<br />

here are a few differences:<br />

KORD 192335Z 2000/2106 14012G18KT 6SM -SHRA SCT015<br />

BKN035 
FM200100 17012G20KT P6SM BKN035 BKN060 
TEMPO<br />

2003/2004 5SM -TSRA BKN018CB 
FM200400 20012G20KT P6SM SCT020<br />

SCT050 SCT120<br />

Location<br />

As usual, the ICAO code is given. In this case, KORD.


Time
<br />

This report was generated at 192335Z. Translated, it was reported on the 19th day<br />

of the month at 2335Z.<br />

Effective Dates/Times<br />

This TAF is effective 2000/2106. This means 20th day of the month at 0000z (2000)<br />

between (/) 21st day of the month at 0600z (2106)<br />

On the rest of the first line, we get the start of the forecast. In this case, 0000z on<br />

the 20th day of the month.<br />

FM200100 means basically from this time forward ( 20th day of the month, 0100z)<br />

this is what the weather will be (until changed on another line).<br />

TEMPO 2003/2004 is a small slot of time where the forecast (on the remaining part<br />

of the line) will be valid. In this case, on the 20th day at 0300z <strong>to</strong> 20th day 0400z.<br />

The rest of the data shown are things that are common between <strong>METARs</strong> <strong>and</strong> <strong>TAFs</strong>.<br />

Look the data up for questions as you are planning <strong>and</strong> using this data, so you’ll get<br />

use <strong>to</strong> it.<br />

Additional information can be found HERE<br />

That does it for our simple explanation <strong>and</strong> introduction <strong>to</strong> <strong>TAFs</strong> <strong>and</strong> <strong>METARs</strong>!<br />

Throttle On!<br />

Chris Palmer

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