After a rather quiet June, regarding thunderstorm activity in France, since 6 July 2023 several rounds of severe thunderstorms have affected western Europe. 

The most severe thunderstorms so far occurred in central/eastern France on 11 July, producing very large hail, severe wind gusts and flash floods. 

The following map shows a screenshot of the D4Weather interface that provides all kinds of severe weather alerts on a daily basis. The red rectangle encloses the areas affected by very large (>5 cm) and giant hail (>10 cm). Our forecast for hail size was spot on in many affected areas, forecasting hail up to 8.5 cm in diameter in Neulise (42590), west from Lyon, where hail up to 11 cm in diameter was reported.

Our R&D team continues advancing the hail size forecasts, and soon a new product will be launched for post-processing of severe thunderstorms. If you wish to learn more about it, contact-us!