United Kingdom Advisory Storm Forecasts (UKASF) is a voluntarily-run organisation providing thunderstorm (convective) forecasts for the United Kingdom. The organisation was founded in April 2008 and is run by a small team of experienced meteorologists and meteorology students, with varying backgrounds and locations around the United Kingdom.
Our aim is to provide accurate convective forecasts each and every day, all year round to highlight areas around the United Kingdom that hold potential for thunderstorms, and in some cases severe weather.
Forecasts for thunderstorms are issued each evening and are valid for the whole of the following day. The forecasts are accompanied by a map with each threat level plotted as an overlay onto a zoomable Google map. A detailed text summary highlights the regions at risk of convective weather and explains fully the setup and conditions that may allow convective weather to occur. The threat levels have been specifically created for typical convective setups experienced across the United Kingdom and cater specifically for excessive precipitation, damaging hail, tornadoes and disruptive convectively-induced winds - for more information on the threat levels click here.
Forecasts are issued even on days with little or no convective weather expected and usually address the reasons behind why there will be a lack of convective activity. As the service is voluntary, however, there may be occasions where forecasts are not issued, or issued later than normal. If no forecast is issued it must be assumed that this is due to a lack of forecasters available, and that convective or even severe weather is still possible. This is primarily the reason why we aim to issue forecasts every day, to alert the public both when convective weather is and isn't expected.
It must be noted that although the forecasts may be reliable, it is the responsibility of the Met Office to warn the public of severe weather - you can view the latest warnings issued here.
After careful consultation, it was decided that we will now concentrate solely on just United Kingdom and Ireland, and it's associated islands, and will no longer issue forecasts for North West Europe or surrounding seas (such as the North Sea) since this takes a lot of additional time to study the forecast conditions and then plot onto the map. We apologise for any inconvenience this may cause to those who may have used our forecasts for outside of the United Kingdom previously.
Before the move to Google maps, we previously provided a widget which enabled users of our forecasts to place a small map on their websites with the latest forecast map. We are currently designing a new widget that can incorporate the new implemented forecast system. Many more features for the site are currently planned and will be released over the coming months.
UKASF is a voluntary service, and no funding is provided for either the costs to run the host servers or for the forecasters or web designers who spend some noteworthy time dedicated to producing forecasts and/or designing the website respectively. Therefore, we welcome any donations you may wish to offer. We are currently designing a system to allow users of our services to submit donations.