Storm Forecast
Valid: Sun 19 Aug 2007 06:00 to Mon 20 Aug 2007 06:00 UTC
Issued: Sat 18 Aug 2007 11:27
Forecaster: DAHL

SYNOPSIS

Large-scale upper trough is present over western Europe and will make only little eastward progress during the period. A SFC low is expected over the North Sea on Sunday morning and should slowly weaken on its northward track. Well-pronounced LL frontal boundary will stretch from the N Iberian Peninsula across the N Mediterranean into the Belarus on Sunday 12Z per GFS 06Z.

DISCUSSION

... eastern Europe ... Balkans ...

Focus for convective development will be the main frontal boundary over eastern and central Europe, as well as mesoscale features and orography to its south. CAPE should climb into the 500 to 1000 J/kg range, and deep shear is simulated to be in the 10 to 15 m/s range. Given rather steep lapse rates and dry mid-level environmental air, some storms may develop into weakly organized multicell clusters, capable of strong wind gusts and some hail, but likely not meeting the level-one criteria.

... Benelux States ... W Germany ... E France ...

Along and ahead of a weak cold-frontal boundary trailing from the SFC low expected over the North Sea by Sunday midday, scattered thunderstorms are anticipated over the Benelux countries, E France, and western Germany. CAPE and shear should be quite weak, so the threat for organized severe weather seems to be quite low.

... SW Mediterranean ...

CAPEs in the 500 to 1000 J/kg range, steep mid-level lapse rates and 20 m/s deep-layer shear may be supportive or a few severe thunderstorms over the SW Mediterranean. Main threats should be large hail and severe wind gusts.