Lesson 22: Understanding and Decoding taf Reports 

Welcome Back!

Today, we’ll dive deeper into the second – and last – kind of weather reports for pilots, and how to decode them.

Let’s do a quick review from last week!

METAR and TAF reports are two types of aviation weather reports used by pilots and meteorologists to understand current and forecasted weather conditions at airports.

Just like the weather guy on TV, meteorologists send out these special reports to pilots and update them as needed.

Pilots use both METAR and TAF Reports to plan their flights and identify potentially hazardous weather.

Here’s a fun fact: Did you know that helicopter pilots also use METAR and TAF reports?

Quiz Question: METAR Reports

METAR Reports let pilots know about the _____ current weather conditions.

• Current

• Future

Answer: Current

Bravo! METAR Reports provide real-time weather information around an airport, helping pilots know what the weather is like right now.

Awesome! Now, let’s see if you remember how often pilots get METAR Reports.

Quiz Question: How often are METAR Reports Issued?

• Every hour

• Every 12 Hours

• Every 30 Years

Answer: Every hour

Nice! Pilots are issued METAR reports every hour because it shows them the most current, up-to-date weather information. 

And finally, what is a METAR Report called when the weather gets really, really, alarmingly bad?

Quiz Question: When the current weather gets especially bad, pilots get sent a _____ SPECI Report.

• SPICY

• SPARKY

• SPEEDY

• SPECI

Answer: SPECI

Fantastic! If the current weather gets really bad, pilots are sent a special report that we call a SPECI Report!

Phew! Great work! Now, let’s do a refresher on the key differences between METAR and TAF Reports.

METAR Reports provide information about the current weather at an airport, and TAF Reports forecast future weather information at airports. 

Oh, that’s right! If pilots get METAR updates every hour, how often do they get TAF updates? 

TAF Reports show the weather for the next 24 to 30 hours at an airport. Pilots get updated TAF Reports every 6 hours. 

So, why do pilots even use TAF reports when they can use a METAR reports, too?

Pilots use TAF reports for flight planning and figuring out what the weather changes might be during their mission.

This helps pilots plan ahead for expected weather conditions – especially for takeoff and landing, and during really long flights! 

Quiz Question: Can you guess what ‘TAF’ stands for?

• METAR Reports

• Terrain Analysis File

• Totally Accurate Forecast

• Tactical Aviation Forecast

Answer: Terminal Area Forecast

Today’s 🔑 Word!

TAF Report

A TAF Report is a detailed weather prediction for a specific airport, usually for a period of 24 to 30 hours.

TAF reports are updated 4 times a day – every 6 hours – at specific times: 0000Z, 0600Z, 1200Z, and 1800Z.

A TAF report is a prediction, while a METAR report tells us what is actually happening that hour. TAF reports focus only on large airports.

TAF Reports share predictions for wind, visibility, cloud cover, and weather to watch out for.

TAF reports help pilots and airport teams plan and prepare for crazy weather conditions, ensuring safe and efficient flight operations.

TAFs are similar to METAR reports but with fewer locations and less frequent updates. They have similar encoding and provide weather information.

Quiz Question: What does Z Stand for again?

• Zulu Time

• Zombie Clock

• Zebra Time

• Zippy Hour

Answer: Zulu Time

Review

• METARs show current weather, issued every hour

• TAFs show future weather for the day, issued every 4 hours, 6 times a day

Break Time!

Phew! You’ve done a great job so far! Let’s take a much-deserved break.

Welcome Back, Future Pilot!

Decoding TAF Reports

So, how is a TAF report different from a METAR report again?

A TAF report is a prediction, while a METAR report tells us what is actually happening that hour. TAF reports focus only on large airports.

And with the information in a TAF report, there are five main differences: 

What’s exclusive to a TAF Report?

1. Future predictions of the weather

2. The time frame the prediction is valid for

3. How the weather is expected to change

4. The probability of a type of weather happening

Future predictions of the weather 

TAF reports tell you what the weather is going to be like over the next 24 to 30 hours, unlike METAR reports that tell you what the weather is like right now. 

Example: Predicting if it will rain or be sunny tomorrow.

The time frame the prediction is valid for

Validity Period: TAF reports include specific times for each forecasted condition.

How the weather is expected to change 

Trends and Changes: TAF reports explain when and how the weather will change.

The probability of a type of weather happening 

TAF reports detail expected changes in weather, specifying when conditions will improve or deteriorate. 

Great work so far! Now that we understand the difference between a METAR and TAF report, let’s learn how to decode a TAF Report!

I’m not panicking! METAR Reports look like jumbled up letters. Do TAF Reports look similar?

Yes! TAF Reports look just like METAR Reports – they are long strings of texts that show pilots weather information, but for the future, instead!

Let’s decode a TAF report piece by piece! TAFs follow a similar formula to METAR reports, with some key differences. It goes like this:

Decoding the structure of a TAF Report

1. The date and time it was issued

2. Date and time that the forecast is valid for (just for TAFs)

3. The overall trend of the predicted weather

4. Predicted weather conditions

5. Predicted wind strength and speed

6. Predicted visibility

7. Predicted cloud base

8. The airport identifier code

9. Predicted precipitation

10. Any other important notes or information about the future weather

Example TAF Report:

TAF: KBOS 201730Z 201818 10005KT 3SM HZ FEW030 FM2030 20020G40KT 2SM +SHRA OVC010 TEMPO 2122 +TSRA OVC15CB

FM0203 PROB40 5SM -RA
FM0306 NSW SKC

“TAF:” – That’s the type of report – it can say METAR, TAF, or METAR / SPECI. 

“KBOS” – The airport identifier code. This airport code is for Boston Logan International Airport. This is also the ICAO location indicator.

“201730Z” – The date and time it was issued. This report was issued on: Day: 20; Time: 17:30 Zulu Time (UTC) 

“201818” – The date and time that the forecast is valid for (just for TAFs). This only applies to TAFs! The weather forecast on this TAF Report is valid between this day and time: It Starts at Day: 20 at 18:00 Zulu Time / UTC. It Ends at 18:00 Zulu Time / UTC the next day

“10005KT” – The predicted wind strength and speed. This one is Wind Direction: 100 degrees; Speed: 05 knots (almost 6 MPH).

“3SM” – The predicted visibility. The Predicted Visibility is: 3 Statute Miles. This is the perfect amount of visibility to fly your drone in! 

“HZ FEW030” – The predicted weather conditions. In this case HZ: Haze is predicted. FEW: Few clouds. The clouds will start at 3,000 Feet Above Ground Level (Add two zeros to 30!)

“FM2030 20020G40KT 2SM +SHRA OVC010” – Permanent changes: what time specific weather conditions will change. In this case, FM means “FROM.” When there is a more permanent change in the weather forecast, FMs will be issued. This means the new weather conditions will start from the specific time and date given. From 20:30 Zulu time is the time this prediction would start. 

Because the FM forecast will now become the main forecast, it will show pilots all the important weather details, even if some things haven't changed from the original TAF.

Example: If only the wind direction changed, but everything else (like the visibility, the amount of clouds) stayed the same, all of that weather information still has to be included!

They just repeat everything weather-related, even if only one part of it changed. 

Example: If only the wind direction changed, but everything else (like the visibility, the amount of clouds) stayed the same, all of that weather information still has to be included!

“KT” – New Wind information (Heads up! You can always tell this chunk is about the wind, because it ends in Knots, or KT.) 

So, starting at 20:30 Zulu Time, here’s the new report on the wind:  

• Direction: The wind will be coming from a new direction of 200 degrees (South West) instead of 100. 

• Wind Speed: The new wind speed will be at 20 knots, instead of 05 knots. 

So, starting at 20:30 Zulu Time, here’s the new report on the wind:  

1. Direction: The wind will be coming from a new direction of 200 degrees (South West) instead of 100. 

2. Wind Speed: The new wind speed will be at 20 knots, instead of 05 knots. 

3. Wind Gusts: There will be wind gusts at 40 knots!

“2SM” – Visibility: The new visibility will be 2 statute miles instead of 3 statute miles. 

“+SHRA” – These jumbled letters mean three things. 

1. + (plus sign): Heavy  

2. SH: Showers 

3. RA: Rain 

“OVC010” – Cloud layer. This shows how much of the sky is covered by clouds and where the clouds start. The sky can have these types of clouds: 

• Clear (CLR)  

• Few (FEW)  

• Scattered (SCT) 

• Broken (BKN)

• Overcast (OVC)

“OVC” – OVC: Overcast (the sky is completely covered with clouds!) 

“010” – The clouds start at 1,000 feet AGL (add two zeros!) 

“TEMPO” – Temporary changes. 

Unlike permanent weather changes in FM, TEMPO shows pilots temporary fluctuations in weather conditions that are expected to last for less than an hour at a time.

TEMPOs also don’t list all of the weather over again – just the specific weather conditions that are going to change temporarily.  

“TEMPO 2122” – Temporary changes: start and time. But like FMs, they still have start and end times – it’s important to know when these temporary weather conditions are supposed to start! 

So of course, like the FM (From) section, they also set a start and end time.

These temporary changes are predicted to: 

Start: at 21:00 Zulu Time 

End: at 22:00 Zulu Time 

“TEMPO 2122 +TSRA” – Temporary changes in weather. + (plus sign): Heavy. TS: Thunderstorm!  RA: Rain!  Not ideal for flying! 

“OVC15CB” – Temporary changes: cloud layers. This section shows pilots about the temporary cloud situation. OVC: Overcast. The cloud base starts at 1,500 Feet AGL. The type of cloud: (CB) Cumulonimbus Clouds! 

Remember that Cumulonimbus clouds are big thunderstorm clouds? It makes sense that we saw a TS (thunderstorm) ahead. 

“FM0203 PROB40 5SM -RA” – The probability that those changes will happen.

“PROB” – This section shows that the probability of the following conditions will change, and to what.

“FM” – Let’s start with FM. Do you remember what this means? FM means From. So from 2:03 Zulu Time, the following weather conditions might happen:

“FM0203 PROB40” – Probability: there is a 40% probability that: Visibility: the visibility will become 5 Statute Miles, and: Rain: there might be light (-) Rain (RA) 

So, to sum this up, from 2:03 Zulu Time, there’s a 40% probability that the minimum visibility will be 5 Statute Miles, and there will be light rain. 

“FM0306 NSW SKC” – More expected changes! This section provides more expected changes about forecasted weather conditions starting from a specific time! From 3:06 Zulu Time.

“NSW” – There are No Significant Weather (NSW) changes! 

“SKC” – SKC: Sky Clear: The sky is expected to be totally clear of clouds.

Great work! I see you’re all a few steps closer to becoming a certified drone pilot. 

Let’s Descent

Great work, everyone!

For Educators: Optional wrap-up activities, games, quizzes, and temperature checks can go here, time-permitting. 

See You Next Time! 

Over and Out.