METAR: Immediate Weather Information:

METAR (Meteorological Aerodrome Report):
METAR reports are updated every hour (or more frequently if needed) and provide current weather data, including visibility, wind speed and direction, temperature, cloud cover, and atmospheric pressure at a particular airport. This report is essential for pilots to understand the immediate weather conditions at the airport they are flying to or from.

TAF: Weather Forecast for Planning:

TAF (Terminal Aerodrome Forecast):
TAF reports offer a forecast of expected weather conditions over a 24 to 30-hour period, with updates issued every six hours. Pilots use TAFs to anticipate weather changes, such as changes in visibility, wind, and cloud coverage, which helps in flight planning and ensuring safety throughout the duration of the flight.

Quick note on difference of report lengths::

METAR reports are much shorter and typically only a single line because they are reporting on weather in the moment.

TAF reports are typically several lines due to reporting on a weather forecast over a period of 24-36 hours. There’s more to decipher because there’s more information on TAF reports.

Below is an example of a METAR report at KMDW airport:

Weather Elements on METAR & TAF Reports:

METAR and TAF reports cover nearly the same elements, with just a few differences given whether the weather is able to be a forecasted prediction (TAF) or immediately displayed (METAR).

How Weather Elements are Displayed:

The two visual aids below show you how METAR and TAF reports layout relevant weather data.

** This is meant to be an overview to show you where we’re going in this lesson. In the next part of this lesson, you’ll learn one weather element at a time how to read these. These may look like a foreign language at first, but step-by-step you’ll see it’s quite practical!

1. Wind Direction and Speed

Making flight mission decisions based on the speed and direction of the wind at any given time will influence takeoff and landing suitability and planning for in-flight navigation paths. If winds are too high, you may need to rethink your flight plan.

Instructions:
The first three digits indicate the wind direction in degrees, and the following two digits represent the wind speed in knots. If there is a “G” followed by additional digits, this indicates gust speeds.

For example, “25015G25” means winds from 250 degrees at 15 knots with gusts up to 25 knots.

Other Examples:

• “11012G18KT” means wind from 110° at 12 knots, gusting to 18 knots
• “33015G20KT” wind from 330° at 15 knots, gusting to 20 knots

Quiz to Test Your Wind Direction & Speed Reading Skills:

2. Visibility in Statute Miles

This indicates how far you can see in the given weather conditions. This is absolutely essential, especially if it reads less than 3 statute miles, which is less the legal minimum visibility required to fly.

Instructions: Reading visibility on TAF or METAR reports:

Look for the distance in statute miles (SM).

• If you see a P followed by the distance in Statute Miles, the P stands for “greater than’. (P6SM means visibility greater than 6 statute miles – or think of the P as you can see “Past 6 Miles”.)

Examples:

3. Sky Condition with Cloud Cover & its Altitude

Important for when you are planning your flight path, and for and for predicting potential turbulence and visibility.

METAR & TAF reports report on the following about sky condition and cloud cover:

• cloud type (i.e. cumulonimbus)
• altitude (i.e. altitude of cloud ceiling)
• coverage (i.e. scattered, broken, or overcast clouds)

Instructions:
Reading cloud cover on a TAF or METAR report:

There are several acronyms for sky condition that these reports use to describe the cloud cover (i.e. OVC for overcast), followed by a number representing the cloud cover’s altitude in hundreds of feet.

This matters because, for instance, if a TAF report is letting you know tomorrow morning until noon there will be overcast clouds at 300 feet before clear skies come about later in the day, you’ll likely want to plan your flight later in the day when the conditions are far more ideal for drone flight.

Visual Aid:

Below is a sample TAF report, where the highlighted purple markers how you the forecasted sky condition and cloud cover + its altitude. The bulleted list below shows what each purple highlight representst:

• BKN030 = broken clouds at 3,000 feet
• OVC008CB – overcast clouds at 800 feet with cumulonimbus clouds
• OVC025 = overcast at 2,500 feet
• OVC008 = overcast at 800 feet
• BKN012 = broken clouds at 1,200 feet
• SKC – skies are clear

4. Temperature & Dew Poin

When the temperature and dew point are close, the air is nearly saturated with moisture, which can lead to fog, mist, or low visibility conditions. Low visibility can affect the drone’s ability to navigate and the pilot’s ability to maintain visual line of sight.

METAR Report Includes:

• Temperature – in °C. Temperature affects aircraft performance, including takeoff distance and engine efficiency.
• Dew Point – in °C. Dew Point indicates the likelihood of fog or low clouds, which can impact visibility and safe landing.

How to read temperature and dew point on a METAR report:

• Look for the two numbers separated by a slash, with the first number representing the temperature in degrees Celsius and the second the dew point.

• 25/17 = temperature is 25°C, and the dew point is 17°C
• 17/6 = temperature is at 17°C, and the dew point is at 6°C
• 16/15 = temperature is at 16°C, and the dew point is at 15°C

Quiz to Test Your Temp & Dew Point Skills:

5. Significant Weather (i.e. rain)

Knowing if rain, thunder, snow, fog, etc are forecasted for your flight will absolutely influence your flight plan.

Instructions:
Reading Weather on METAR and TAF Reports:

Look for abbreviations indicating various weather phenomena such as rain (RA), snow (SN), fog (FG), or thunderstorms (TS), typically listed alongside other meteorological parameters.

Visual Aid & Examples:

6. Probability of Occurring

Probability data occurs only on TAF weather prediction reports. This is because it is only relevant in terms of future forecasts.

Instructions:
Reading Probability on TAF Reports:

Look for the abbreviation “PROB” which stands for “Probability”, followed by a numerical value, indicating the likelihood of specified weather happening during the forecast period. This will be expressed as a percentage. (i.e. 40% probability of weather occurring during forecasted period.)

Visual Aid & Examples:

7. Current Atmospheric Pressure

Atmospheric pressure helps pilots understand the current state of the atmosphere, which can affect aircraft performance, altitude calculations, and weather patterns.

Instructions:
Reading Probability on METAR Reports:

To read atmospheric pressure on a METAR report, look for the “A” followed by a numerical value, representing the atmospheric pressure in inches of mercury (inHg).

Visual Aid & Examples: