CONVECTIVE FORECAST
VALID Tue 04 Oct 17:00 - Wed 05 Oct 06:00 2005 (UTC)
ISSUED: 04 Oct 16:44 (UTC)
FORECASTER: DAHL

SYNOPSIS

Upper block pattern persisting across Europe ... with quasi-stationary upper cut-off low covering the NRN and WRN Mediterranean Sea ... and an EWD building upper high over NRN Europe. Large SFC high ... expected to be centered over the Baltic-Sea region by Wednesday 06Z ... is covering most of Europe ... weak low pressure areas analyzed over the central Mediterranean and the Black-Sea region.

DISCUSSION

...central Mediterranean...
Ascent E of the Mediterranean upper low overspreading weakly unstable air mass should continue to support convective activity through Tuesday evening/night. Deep shear should be in the 15 to 20 m/s range ... with increasing low-level shear towards eary Wednesday morning per MM5. Kinematic and thermodynamic setup should be marginally supportive of isolated severe evolution ... though threat should decrease towards late evening with the loss of diurnal heating. Expect an isolated severe wind/hail event ... though an isolated tornado cannot be discounted given weak low-level capping and low LCL heights as well as increasing shear late in the period. Threat is too conditional for a SLGT however.

Convection in the center of the upper low in deep/modified polar air should diminish over Italy and adjacent isles with diurnal cooling ... but may persist over the NW Mediterranean Sea and along the coasts. Though convection may be rather shallow and weakly electrified ... an isolated waterspout or two could occur.

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