Storm Forecast
Valid: Sat 07 Feb 2009 08:00 to Sun 08 Feb 2009 06:00 UTC
Issued: Sat 07 Feb 2009 08:08
Forecaster: DAHL

SYNOPSIS

A deep, large-scale trough has settled over western Europe, making only minimal eastward progress during the period. Towards Saturday evening, this trough will close off into an upper cut-off cyclone over the cental Mediterranean. At low levels, the upper trough is accompanied by an extensive but comparatively weak cyclone, covering practically all of Europe. By the end of the period, this low-pressure system will develop a bipolar structure, with one center over S Scandinavia and another one over the N Adriatic region, evolving in response to the cut-off process. The cold front trailing from the SFC low will move across the western and central Mediterranean on Saturday.

DISCUSSION

... western Mediterranean ... Aegean region ...

Along and ahead of the Mediterranean cold front, scattered convective activity persists and should increase during the day. Instability will be quite marginal and comparatively shallow, but deep shear in excess of 25 m/s will likely support isolated severe evolution. Severe wind gusts should be the main threat, but given LLS in excess of 10 m/s over the S Balkan as well as over W Turkey, an isolated tornado or two may also well occur.

In the wake of the front, cellular convection has developed over the western Mediterranean. This activity is rather weakly sheared, though LLS may be greatly enhanced over the Islands, which may hint at a threat for an isolated brief tornado or two, but this threat seems to be too insignificant for a categorical risk.

... N coast of Morocco ...

Between Morocco and Iberia, some thunderstorms are on going but will weaken during the next couple of hours, per model guidance. 12 m/s LLS along the coast of Morocco suggest that land-falling convection may briefly develop low-level mesocyclones with an attendant threat for an isolated tornado or two, but given a lack of DLS, storm organization should be too poor for a robust severe weather threat.

... North Sea ...

Isolated lightning may accompany rather shallow cellular polar-air convection over the North Sea, but the electric activity should remain too isolated for a thunderstorm forecast area.