Schweizer Sturmforum

...S Germany, Alps...

This area lacks any substantial large-scale feature to provide strong synoptic-scale lift. However, along with intensifying diurnal heating, evapotranspiration and steep lapse rates, NWP mesoscale models predict a widespread CI in the afternoon hours over S Germany and W Austria. GFS is more positive and includes whole Alpine area in the zone of locally lowered pressure producing widespread convective precipitation. Small to locally moderate instability (> 1500 J/kg ML CAPE) and low shear will favour slowly moving cells capable of producing heavy precipitation, large hail up to 3-4km and downburst-type severe wind gusts. Thanks to wind field interacting with mountains, a local enhancement in vertical shear and helicity is possible, and thus supercell thunderstorms cannot be ruled out. Convection should fade in the nighttime hours along with disappearing instability.

Michael (Untersee) hat geschrieben:Vorsicht, die kräftigeren Zellen haben Downburst-Potenzial, z. B. die Zelle über dem Neuenburgersee!

Gruss, Michael