Glidemet

Where’s the ratings?

There aren’t any, nor will there be. I’ll tell you what conditions you can expect where, and it’s up to you to decide how far or fast you can fly in them.

Didn’t that post just change?

I’ll often edit posts for up to an hour after first posting, usually only small changes after I’ve had a bit longer to think.

What’s this forecast for?

Year-round, to forecast which of the two weekend days will be the best to go gliding on. During the soaring season there is a daily soaring forecast for the following day. I will attempt to give as much warning as possible of a very good soaring days coming up, but do not expect long lead times or perfection—-it is hard to accurately forecast soaring conditions more than a day or two ahead.

What area does this forecast cover?

England south of the Pennines, and all of Wales.

What do you forecast for?

Ridge and wave as well as thermals, and general weather for non-soaring days too.

When are the forecasts availabe?

A forecast is made each weekday evening usually by 8.30pm; sometimes a little later. Occasionally a forecast will be missed when I don’t have access to a computer.

In addition, a review of the previous week’s forecasts and an early-outlook is made on Monday.

Why are there no on-the-day forecasts?

I don’t have time in the morning/I don’t wake up early enough! I recommended that pilots check the weather themselves on the day using the links on the left. Very occasionally there’s a morning update.

How are these forecasts produced?

I study and compare the output of the best numerical weather prediction (NWP) models available via the internet. Then I use my knowledge of meteorology, how each model works, and how the data they produce affects gliding, to write a text forecast.

I want to know more about forecasting.

Read this.

What is RASP?

RASP stands for Regional Area Soaring Predictions. It is a WRF model modified specifically to produce soaring forecasts. It was developed by Dr. John W. (Jack) Glendening in the US. A version is run by Paul Scorer for the UK, giving soaring forecasts for up to five days ahead. You can view the output.

What’s so great about RASP?

Previously soaring forecasts were made by looking at forecast soundings from the global GFS model, which has a 36 km grid resolution, and then making educated guesses about what those soundings meant. RASP uses a 12 km grid WRF model to produce forecasts, making it more detailed, it has been tuned specifically for soaring, and it produces charts that are directly relevant to pilots - such as cumulus cloud base and thermal updraft strength. You can read about the main RASP parameters. However, RASP does have limitations.

How often are you wrong?

Find out for yourself!