CONVECTIVE FORECAST
VALID Sun 23 Oct 07:00 - Mon 24 Oct 06:00 2005 (UTC)
ISSUED: 23 Oct 07:08 (UTC)
FORECASTER: DAHL

SYNOPSIS

As upper trough ... currently over Spain closes off into an upper cut-off low moving into the SW Mediterranean Sea ... seasonably strong meandering zonal upper flow is establishing over central and northern portions of Europe. Embedded trough and associated cold front are expected to affect N-central and NE Europe until Monday 06Z.

DISCUSSION

...north-central into NE Europe...
Two frontal boundaries are analyzed over central Europe ATTM ... with rather moist and weakly unstable air over SRN portions of Germay ... and somewhat cooler air N of it ... which also happens to be slighly unstable given current convective activity over NW Germany and Holland ... though soundings do not reveal this convective potential. Given increasing large-scale UVVs associated with the approaching upper trough ... and mesoscale ascent along the frontal boundaries ... precip with imbedded convective cells/TSTMS should continue through the period. Though CAPE is minimal ... rather strong shear profiles are in place ... with 10 to 15 m/s shear expected in the lowest km. This may support an isolated/brief tornado/damaging-wind event ... though shallow nature of convection may limit lightning activity. Threat should be quite low however ... and a categorical risk is not necessary ATTM.

...Mediterranean...
CAPE up to 1000 J/kg should be present across the Mediterranean. Capping is minimal and BL is nearly saturated ... which could cupport a few waterspouts. Deep shear of about 15 m/s is in place over the W Mediterranean ahead of the developing cut-off low ... so that a few multicellular storms with marginally severe hail and strong wind gusts may occur. LLS should be somewhat stronger over the Ionian Sea and the SW coast of the SRN Balkans ... so that tornado threat will be enhanced there ... though deep shear should be rather weak and storms may struggle to organize ... yielding rather localized/brief severe threat ... altogether not warranting a SLGT.

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