Storm Forecast
Valid: Thu 10 Aug 2006 06:00 to Fri 11 Aug 2006 06:00 UTC
Issued: Thu 10 Aug 2006 07:05
Forecaster: GATZEN

SYNOPSIS

Low geopotential remains over Europe ... with centers over the North Sea, Adriatic, and western Russia rotating around each other. During the period ... the Adriatic trough moves into western Black Sea region, while the North Sea trough evades into western Germany. Strong upper jet streaks are expected to spread over British Isles / France as well as eastern Mediterranean / Black Sea at the trough's periphery ... while rather strong upper jet will remain over Mediterranean connecting both jet streaks. At lower levels ... hot and rather dry airmass is present over Iberian Peninsula and Turkey ... while relatively warm/moist airmass has spead over most of Mediterranean ... parts of eastern Europe ... and parts of Scandinavia. Cool Atlantic airmass spreads into northwestern Europe.

DISCUSSION

Southern Balkans, western Black Sea region

Strong upper short-wave trough travels northeastward into western Black Sea region during the period. WAA and DCVA is expected at the eastern flank and QG forcing is forecast by latest model output. Associated deepening surface low pressure system over southern Adriatic moves into northern Aegean and Romania later on. To the east of this low ... easterly surface winds and increasing low-level moisture are forecast by latest model output ... and CAPE is expected to develop over Greece and western Black Sea region. ATTM ... thunderstorms/MCS have reached western Greece moving northeastward. Given strong DLS ... thunderstorms are well-organized and will likely produce severe wind gusts and isolated large hail duirng the next hours. Rather dry airmass over Greece should limit severe potential during the day ... while increasing moisture over Aegean Sea and western Black Sea region should lead to new convective activity during the afternoon/evening/night hours. Limiting factor will be stratiform coulds/rain and rather poor insolation. Given moderate DLS as well as enhanced LLS ... a few mesocyclones may form ... capable of producing large hail and severe wind gusts. Chance for tornadoes should be locally enhanced ... although boundary-layer may be quite stable due to relatively cool low-level airmass. During the night ... increasing LLJ north of the surface low is expected ... and thunderstorms should merge into one or two MCS moving NE-wards with severe wind gusts the main threat ... reaching southern Ukraine late in the period.

Northwestern Italy

A new surface low is forecast to develop over Italy. To the north ... surface winds are likely east and should advect moist low-level airmass into northern Italy. As the upper jet streak approaches ... at lest weak QG forcing is expected. It is not ruled out that convective storms will develop ... and given increasing DLS ... chance for supercells is enhanced ... capable of roducing large hail and severe wind gusts. However ... initiation is questionable given rather poor moisture and expected weak forcing ... and current thinking is that strong/persistent thunderstorms will not develop.