Storm Forecast
Valid: Wed 13 Apr 2011 06:00 to Thu 14 Apr 2011 06:00 UTC
Issued: Tue 12 Apr 2011 21:56
Forecaster: PUCIK

No threat levels have been issued.

SYNOPSIS and DISCUSSION

A rather complex synoptic scenario is forecast over Europe with prevailing low geopotentials covering most of Central and Eastern parts of the continent. Several smaller-scale ridges/short-wave troughs or lows are simulated within this broad region. Low geopotentials are associated with rather cold and dry airmass, that has overspread these regions, behind the cold front, that is advancing towards southeast. As of Wednesday 06 UTC, it will be stretching from Central Italy to Northern Romania. This frontal system with shallow surface low is interconnected with a short-wave trough located at mid-levels of troposphere, providing necessary lift at its forward flank with PVA during its advance to the southeast. This short-wave trough along with a cold front will serve as the dominant features regarding the thunderstorm development during the day.

Models tend to agree on the general lack of thunderstorm activity over Europe, given by the advection of rather dry and cold airmass on the forward flank of the surface high over Western Europe. Even ahead of the cold front, meager instability is forecast, mainly because of the low dew points over Southeastern Europe. The exceptions might be the eastern coastal areas of the Adriatic Sea, Eastern Bulgaria/ Southeastern Romania and Western Black Sea where at least marginal CAPE is simulated by GFS and ECMWF. Nevertheless, isolated thunderstorms might form anywhere along the front especially thanks to the strong forcing provided by the short-wave trough with activity spreading overnight into the western Aegean Sea. Small degree of instability, often lacking the overlap with the zones of high wind shear, precludes the severe threat with thunderstorms, thus no level is introduced.