Storm Forecast
Valid: Sat 24 Mar 2012 06:00 to Sun 25 Mar 2012 06:00 UTC
Issued: Sat 24 Mar 2012 01:12
Forecaster: VAN DER VELDE

SYNOPSIS and DISCUSSION

Surface high pressure is present throughout Europe, with the main high located over the North Sea. However, a slight upper trough can be found over central and southern Europe, with low values of MLCAPE developing over land in the afternoon yielding isolated thunderstorms. The main dynamic feature is the small upper low/PV max moving from Corsica to Sicily during the period. It has some CAPE associated with it and warm air advection to the east. More than 20 m/s deep layer shear partially overlaps, but the veering winds with height and somewhat enhanced SREH and 0-1 km shear are in the warm sector while CAPE is in the cold air. A waterspout or marginal large hail event is not ruled out, but the threat seems too small for a level 1.
Another low lies near Morocco and Portugal, advecting warm air to the north in which elevated showers/thunderstorms can occur. Over Morocco convection will be surface-based, MLCAPE locally larger than 1000 J/kg and cloud bases higher than 2000m, but shear is quite weak.