Storm Forecast
Valid: Mon 06 Dec 2010 06:00 to Tue 07 Dec 2010 06:00 UTC
Issued: Mon 06 Dec 2010 08:26
Forecaster: DAHL

A level 1 was issued across the western Iberian peninsula mainly for excessive convective rain and to a lesser extent for severe wind gusts, hail, and tornadoes.

... SYNOPSIS ...

Ahead of an upper low over the E Atlantic, a rather extensive SFC low maintains an influx of warm/moist, and slightly unstable air into Iberia. Otherwise, a deep, large-scale trough filled with cold air is covering the central and northern portions of Europe. The northern extent of the warm air should remain rather stationary and stretch from central France across southern Germany into eastern Europe.

... DISCUSSION ...

... Iberian Peninsula ...

It seems that a few 100 J/kg of CAPE will persist off the Iberian west coast and over the western parts of the peninsula ... gradually diminishing farther inland/east. Peristent QG ascent should maintain convective activity thoughout the period. It seems that the cells may have a tendency to become elevated as they make landfall, so that the primary threat would be excessive convective rainfall. However, quite strong shear profiles remain in place, suggesting that any storms that become rooted in the boundary layer may become organized into line segments or mesocyclones. Though the primary threat with this activity should be marginally severe winds/hail ... low LCL heights along with LLS of order 15 m/s suggest that a few tornadoes could occur as well.