Forecast Update
Valid: Sun 20 Nov 2011 14:00 to Mon 21 Nov 2011 06:00 UTC
Issued: Sun 20 Nov 2011 15:53
Forecaster: VAN DER VELDE

A level 1 was issued for parts of southern and eastern Spain, northern Morocco/Algeria and Corsica mainly for excessive convective precipitation.

UPDATE

Thunderstorm probability lines have been altered to reflect better CAPE and convergence distributions seen in various WRF, ECMWF and HiRLAM models. Palma de Mallorca and Murcia 12Z soundings indicate almost 1000 J/kg CAPE. Cagliari 12Z shows potential instability and several models produce storms along the east coast of Sardinia and Corsica.

Within the level 1 areas, low level flow is directed onto the coast where orographic lifting can sustain storms for longer periods of time. Isolated slow-moving storms are expected to occur. Across the east coast of Spain some 10 m/s deep layer shear can be present which enhances regeneration of cells. Bunkers storms motion is around 5 knots only in a large area. Currently steady storms are already occurring in southern and eastern Spain. Local flash floods are likely. Isolated waterspouts may occur as well.