Storm Forecast
Valid: Sat 29 Nov 2008 06:00 to Sun 30 Nov 2008 06:00 UTC
Issued: Fri 28 Nov 2008 19:37
Forecaster: DAHL

SYNOPSIS

A deep and broad upper long-wave trough is covering the western and central parts of Europe. Imbedded vorticity maxima are pivoting about the base of this trough, with one such vort max crossing Iberia, France, and the NW Mediterranean during the period. At low levels, the large-scale trough is accompanied by an extensive SFC-low pressure complex, likewise covering much of western and central portions of Europe.

DISCUSSION

... western Mediterranean regions

Main focus for convective development will exist ahead of the NW Mediterranean vort max and a concomitant plume of warm air ahead of it. Though CAPE is expected to be very weak amidst this plume, strong shear profiles will be in place, and some threat for bowing/line segments as well as mesocyclones exists. Expect marginally severe hail/wind with the strongest cells, and possibly also an isolated tornado or two.

... Extreme W France ... extreme N Spain ...

Polar-air cellular convection should persist over the E Atlantic, including the Gulf of Biscay. Strong LLS over France and N Spain should allow landfalling convection to become briefly organized, before decaying as a result of low-level stabilization. This activity may well produce isolated/short-lived tornadoes, as well as some hail/wind gusts which may briefly attain severe levels.