CONVECTIVE FORECAST
VALID 06Z TUE 25/01 - 06Z THU 27/01 2005
ISSUED: 25/01 22:52Z
FORECASTER: GROENEMEIJER

There is a slight risk of severe thunderstorms forecast across western Greece and southern Albania

General thunderstorms are forecast across parts of the western Mediterranean Sea, the Tyrrhenean Sea, southern Italy, the Ionean Sea and the southern Adriatic Sea, the southern and eastern Balkans, Greece and parts of Turkey.

SYNOPSIS

Wednesday at 06 UTC...a blocked flow pattern is expected over Europe. A high pressure system at mid-tropospheric levels is located 500 km west of Ireland, and a low just south of the Cote d'Azur. Between the systems a strong northeasterly jet is forecast from the North Sea to northern Spain and another jet is expected south of the low from southern Tunesia to southern Greece.

DISCUSSION

...western Greece, Albania...
A few 100s of J/kg MUCAPE are expected to form north of the axis of the jet. A trough located over Tunisia at 06Z is expected to move rapidly downstream and induce strong mesoscale rising motions over the area in the late afternoon and early evening. It is expected that widespread thunderstorms form that will likely evolve into an MCS. As 0-6 km shear and 0-1 km shear are expected to be around 20-25 m/s and 15 m/s respectively, storms can well become severe and pose a threat, chiefly of severe gusts and secondly of isolated tornadoes and marginally severe hail as well as abundant snowfall inland. The storms activity will probably diminish after the passage of the shortwave trough, but continue at lower intensity into Thursday.

...western Turkey and northeastern Greece...
Rising motionins in a rather strongly sheared environement will likely cause a couple of thunderstorms to form during Wednesday afternoon. Given that low-level shear is strong (20 m/s in the 0-1 km layer) a threat of severe wind gusts and parhaps even a tornado or some marginally large hail will exist. The threat is expected to be lower than across western greece as forcing for upward vertical motion will probably be smaller across this area.

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