Storm Forecast
Valid: Thu 17 Dec 2009 06:00 to Fri 18 Dec 2009 06:00 UTC
Issued: Wed 16 Dec 2009 18:28
Forecaster: GATZEN

A level 2 was issued for western Greece and south-western Turkey mainly for excessive rain.

SYNOPSIS

At the southern edge of a deep polar trough centered over Europe, a strong westerly jet affects the Mediterranean. An embedded short-wave trough moves into the Balkans late in the period. At lower levels, an intense low pressure system propagates into the Aegean Sea, advecting a tongue of moist maritime air into Greece and Turkey.

DISCUSSION

Greece, Aegean, Turkey

Strong lift is expected in the range of the warm sector of the approaching low across the east Mediterranean. Affected air mass is rather moist at low-levels, while the cold mid-level air and continuing lift will likely lead to further destabilization. During the night, latest model output suggests more than 500 J/kg CAPE. Given the strong lift especially along the western coasts of Greece and Turkey, initiation of thunderstorms is likely. Given the strong deep layer vertical wind shear of about 15-20 m/s, storms are forecast to organize, and multicells will likely lead to excessive precipitation. Additionally, strong low-level vertical wind shear of 15 m/s in the lowest 3 km is likely in the warm sector, and given favorable veering profiles, embedded mesocyclones may produce tornadoes. Severe wind gusts are not ruled out given the strong low-level winds.

Southern Mediterranean

To the south of a cold front that moves into northern Africa late in the period, a tongue of moist air mass is present over the south Mediterranean Sea. Given rather cold mid-levels, weak instability is forecast to develop, and some thunderstorms are forecast. Given rather strong low-level vertical wind shear, an isolated tornado is not ruled out with these storms.