Mijn hemel. Ze verwachten daar nogal wat. Ik had daar wel willen zitten, om prachtige luchten en bliksems te zien.
During the next couple of hours, convection is forecast to go on over southeastern France and Alpine region. As low-level heating increases, convective cells may root to the boundary-layer. With weak low-level winds and rather strong south-westerly wind aloft, as well as favorable veering profiles, resulting in 20-30 m/s DLS, locally 10 m/s LLS, and 150-250 J/kg SRH, thunderstorms that root to the boundary-layer will rapidly become well-organized and may evolve rotating updrafts. Supercells that form will likely produce (very) large hail. Isolated severe wind gusts are not ruled out with the stronger storms. Given low LCL heights/high low-level moisture, tornadoes are possible in regions where diabatic heating is present, increasing low-level buoyancy. Limiting factor is rather weak low-level vertical wind shear.
During the day, another focus of intense convection is forecast with the second region of strong upper lift. Current thinking is that thunderstorms will likely initiate along/north of the Pyrenees, spreading rapidly northeastward. Given very favorable profiles, and high instability, well-organized convection is expected. Mesoscale convective systems, including bowing lines and embedded supercells are forecast, capable of producing (very) large hail and severe wind gusts. Given locally favorable low-level veering, a few tornadoes are also forecast, especially over southeastern France, where low-level southerly winds will likely increase ahead of the convective system.
Thunderstorms are expected to spread into the Alps, and northern Italy, where large hail, severe wind gusts and a few tornadoes are still expected.
Additionally, severe flash floods and flooding are expected with the stronger storms throughout the period.
Thunder is good, thunder is impressive; but it is lightning that does the work. - Mark Twain -
