The temperature of the Mediterranean sea is quite high this year. In some ares, temperature at the surface is around 28°C. This is of course due to the hot spring and summer.
This situation is not without consequences :
a medicane was formed close to the Libyan coasts and hit last Friday Greece creating a lot of damages because of the wind and rain
yesterday, in the South of France, because (but not only !) of the intrusion of very warm and humid air from the sea, combined of course with other factors (instability, anomaly in altitude, wind shear), it created a multi cellular thunderstorm which was stationary : each new convective cell (this is why it is a multicellular system) is created in the exact opposite way of the move of the system in altitude because of the wind shear. This creates therefore a stationary thunderstorm which is terrible in terms of rain accumulation because you can get huge quantities of water at the same place during 24h or even more.
This thunderstorm created floating and a lot of damages in France (more than 600mm of rain in 24h)
Unfortunately, other episodes like the ones mentioned above could happen in the coming weeks,...