CONVECTIVE FORECAST
VALID 06Z SAT 17/04 - 06Z SUN 18/04 2004
ISSUED: 16/04 20:51Z +++ CORRECTED 17/04 12:22Z +++
FORECASTER: DAHL

General thunderstorms are forecast across central and eastern Mediterranean.

General thunderstorms are forecast across Poland.

SYNOPSIS

Atlantic upper long-wave trough is progged to dig SE ... and reach W Europe by the end of the FCST period. Southern frontal zone is stretching across the S and E Mediterranean ... ingesting the upper cut-off low over the W Mediterranean Sea during the first half of this period. Weak upper cut-off low will linger over Poland during the period. Intense SFC low ahead of the Mediterranean upper low ... is progged to weaken and to move east into the W Balkan States.

...Central and eastern Mediterranean...
TSTMS are currently present over the Ionian Sea along the cold front curving into the W Mediterranean SFC low. Available soundings do not sample the narrowing warm-sector air mass ... and model fields suggest no CAPE at all over this region. Nonetheless ... models agree on weakening the theta-e plume during Saturday ... which may be an indication of generally decreasing TSTM threat. However ... at least scattered TSTMS should persist along and in the wake of the main cold front ...and maybe develop E of it within low-level WAA regime. 0-6 km Shear will likely be on the order of 20 m/s across the S portions of the TSTMS area ... and given the Saharan history of the warm-sector air mass and associated suspected steep mid-level lapse rates ... a few strong wind gusts may occur. Later observations ... especially of the thermodynamic fields ... will have to be awaited to specify actual convective threat.

...Poland...
Expect scattered weak/shallow diural TSTMS in weakly capped air mass beneath the upper cold pool over Poland. Some stronger wind gusts may occur given rather deep/dry boundary layers ... but organized severe TSTM threat is pretty low.

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