Weather forecasters can more accurately predict when a tornado is likely to hit the UK thanks to a new tool devised in a partnership between the University of Leeds and the Met Office.
Around 30 tornadoes occur in the UK each year, 40% of which develop on cold fronts – but a lack of forecasting methods for these conditions means they strike without warning, explains a statement.
Now researchers at Leeds and the Met Office have for the first time created a prediction for how likely tornadoes are to occur on cold fronts, meaning a more accurate assessment of tornado risk can be made before a cold front crosses the UK.
Matthew Clark, a Met Office scientist who is currently studying for a PhD at Leeds’s School of Earth and Environment, said: “These findings should help to improve the UK forecasts of localised, intense wind damage associated with these kinds of weather system. This should enable organisations and people to take precautions and minimise damage and risk.”
The researchers identified patterns across weather events, establishing which cold fronts were likely to produce a single tornado, which could produce several, and which would produce none.
The research found that most of these tornadoes form when a region of strong winds approaches the front from the cold side. This creates a bulge in the front which helps to make it sharper, increasing the contrast in wind speed and direction across the front. Where this contrast increases over time, tornadoes are more likely to “spin up” along the front. Occasionally, relatively large outbreaks of tornadoes can occur in this situation.
Clark and Parker also used their findings to create a predictive tool, which is already being used on an experimental basis by the Met Office to pinpoint regions at increased risk of tornadoes.
The tool is currently being tested in the Met Office, and was put to use on 29 February this year, successfully predicting the risk of tornadoes in southeast England, with a tornado occurring in Kent as the cold front swept through during the morning.
Image credit: NOAA