TAF Generator
Generate a random TAF, work out the timeline, then decode it to check yourself.
Every generated forecast is valid: it is run through the same parser that reads real TAFs, and it always carries at least one change group.
Take this with you.
The WxDecoder app gives you live weather, maps, route weather, saved examples, and quizzes that make aviation weather stick.
How to practise with the TAF generator
Every generated forecast carries a body plus at least one FM group, and often a TEMPO as well. That is the part of a TAF that is genuinely hard, so it is the part worth drilling.
Pick an hour inside the valid period before you decode. Work out what the forecast says for that hour, then press Decode and compare against the timeline.
Choosing an hour first is the habit that matters. Reading a TAF top to bottom and taking the last line as current is the most common way to misread one.
The change groups are the exercise
The single question that resolves most confusion is whether a group replaces the line above it or sits on top of it. FM replaces. TEMPO does not.
So a TEMPO period has two answers: the prevailing conditions and the temporary ones. Both are shown when you decode, because the temporary set is the one your alternate has to clear.
The change group comparison works through each of them, and the TAF abbreviations list covers the forecast-only codes.
Why these forecasts are always readable
The generator is covered by a test that builds hundreds of TAFs and parses each one, checking that the timeline comes back with at least two periods and a plain-English summary. A forecast that did not decode would fail the build.
The values are realistic in range but invented. Do not plan anything against them.
For a real forecast, the TAF decoder takes live TAFs and airport codes, including military ones with icing and turbulence groups.
Frequently asked questions
Do the generated TAFs include TEMPO groups?
Often. Every one has a body and at least one FM group, and roughly half also carry a TEMPO period, because the overlay behaviour of TEMPO is the part of a TAF most worth practising.
Are military TAF groups generated?
Not yet. The generator produces civil TAFs. To practise the military trailer, paste one into the TAF decoder, which reads the turbulence 5-group, the icing 6-group and the QNH group.
How long is the valid period?
Twenty-four hours, written in the standard four-digit day and hour form on both sides. That is the shorter of the two real periods, and it keeps the timeline small enough to work through in your head.
Can I use these to plan a flight?
No. They are invented forecasts for practice only. Use the TAF decoder with a real airport code for anything you intend to act on, and get an official briefing before you fly.