Schweizer Sturmforum

A level 2 was issued across parts of CNTRL-France for large to isolated very large hail, severe wind gusts and excessive rain. An isolated tornado event is possible.

A level 1 was issued across NE-Spain to France to the Alps mainly for large hail, excessive rain and severe wind gusts.

... France and NE-Spain ...

Placement beneath a divergent upper-level flow regime ahead of the approaching trough results in a prolonged period of synoptic-scale lift already during the start of the forecast period. Hence, temporarily weakening thunderstorm clusters from the previous night affect W-France before noon. Despite scattered thunderstorms and probably lots of cloud cover, ongoing moisture advection from the SE beneath meager mid-level lapse rates and temporal diabatic heating push SBCAPE to 800-1500 J/kg just ahead of the N/NE-ward moving cluster. Therefore the ongoing activity probably re-strengthen over N-CNTRL France beyond noon and numerous severe thunderstorms are forecast. 15 m/s DLS support organized convection with large to isolated very large hail and strong to isolated severe wind gusts. Lack of stronger 0-3 km flow lowers confidence in bow echo development somewhat, but nevertheless degree of CAPE may assist in swaths of cold pool driven severe wind gusts. Areas with highest confidence in more widespread severe were included into the level 2 area.
A structuring vortex over NW-France increases the risk for slow moving nighttime clusters with excessive rain the main risk. The final magnitude of that risk depends on how fast this vortex strengthens with ongoing large model spread (e.g. IFS showing a weaker solution).

Further E over E-CNTRL France, another day with active thunderstorm development along numerous convergence zones is forecast. More sunshine is expected which results in strong MLCAPE of 1000 - 1500 J/kg with higher values along any convergence zone. With mid-level low improving from the SW during the day, DLS increases to 15-20 m/s, resulting in rather straight but elongated hodographs. Early CI is forecast over E-CNTRL France with excessive rain and large hail the primary threat. Thereafter however, the risk of organized multicells and supercells increases to the S (W of Jura Mountains and N of the Massif Central) as more discrete storms (due to lack of forcing) evolve in an improving kinematic setup. Even a low-end tornado risk evolves during the evening with strengthening LL flow and LCLs of 800-1000m. Large to isolated vey large hail and swaths of strong to severe wind gusts are possible with forward propagating small clusters/bowing line segments. This area was also upgraded to a level 2.

Dominic Kurz hat geschrieben:Estofex hat Level 1 und in Frankreich bis zur Schweizer Grenze Level 2 draußen. Es ist von Sturm heftigem Niederschlag, grosser Hagel, Superzellen sowie von einem möglichen isolierten Tornado die Rede.

Wetterfreak_VBG hat geschrieben:
Tut mir leid dich zu enttäuschen, aber das ist noch der Nowcast von Gestern (Sonntag!)