CONVECTIVE FORECAST
VALID Sun 21 Aug 06:00 - Mon 22 Aug 06:00 2005 (UTC)
ISSUED: 20 Aug 21:14 (UTC)
FORECASTER: DAHL

There is a slight risk of severe thunderstorms forecast across Italy and the extreme NW Balkan States.

SYNOPSIS

Mediterranean upper low is expected to continue its slow eastward track ... being centered over the N Adriatic Sea by Monday 06Z. NRN stream trough will cross the Baltic Sea ... with its SRN tip closing off into a small upper low over the Baltic States late in the period. SFC high is progged to build over Finland ... and weak cyclogenesis is expected over the N Mediterranean in response to DCVA at the E side of the Mediterranean upper low.

DISCUSSION

...Italy ... NW Balkan States...
Weakly unstable air mass ... with MLCAPEs of a few hundred J/kg ... is present E of the Mediterranean upper low ... though theta-e fields suggest that dry/cool air will advect across central portions of Italy in the evening hours. Large-scale ascent should aid in TSTM development along the cold front as well as over Italy and the Balkans ahead of the front. DLS on the order of 20 to 25 m/s should support line segments and a few mesocyclones ... capable od producing severe wind gusts ... large hail and possibly a brief tornado or two.

...S Germany...
Scattered TSTMS should also form across Germany in weakly capped and weakly unstable air mass. Though deep shear seems to remain quite marginal ... LLS will increase over the SRN half of Germany per MM5 ... which should promote an isolated severe wind/hail event and possible a brief/weak tornado or two. Organized severe threat should be too low for a SLGT.

...SE Finland ... N Baltic States ... extreme W Russia...
Weak instability is simulated to develop ahead of NRN stream trough across SE Finland ... the N Baltic States and extreme W Russia. 15 m/s deep-layer shear should be in place ... which will likely support muticellular structures ... maybe capable of producing a marginally severe wind/hail event. Allover severe threat should be rather low however.

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