Storm Forecast
Valid: Sun 08 Feb 2009 06:00 to Mon 09 Feb 2009 06:00 UTC
Issued: Sat 07 Feb 2009 22:21
Forecaster: SCHLENCZEK
SYNOPSIS
On Sunday, the main feature for convective activity is a large upper trough over central / southern Europe. Ahead of this trough, moist air is advected into parts of southeastern Europe. A frontal boundary stretches from Libya via Greece towards the northern Balkans and will move eastward while weakening. Southeast of the frontal boundary, an intense 80 m/s upper jet streak stretches from the central Mediterranean towards the Aegean Sea.
Some weakly electrified convection is expected over southern Scandinavia and the Norwegian Sea / northern North Sea. Weak instability and shear should preclude severe weather.
During the second half of the forecast period, an unstable wave west of Iberia will develop into an intense cyclone. This feature should be monitored in the following forecast period as shallow but organized convection may develop along the cold front, leading to an enhanced risk of damaging gusts. The evolution of this low pressure system is rather uncertain but at least isolated severe gusts should be expected on Monday / Tuesday over parts of France and Iberia.
DISCUSSION
...SE Greece, Aegean Sea, Bosporus region, W Turkey...
On Sunday morning, some hundred J/kg of CAPE should be available in parts of the Aegean Sea. In the same area, the left exit region of a strong 45 m/s jet streak at 500hPa is forecast to move northeastward. Associated vorticity maxima should provide enough forcing for convective initiation. 20 - 30 m/s deep layer shear should be in place and storms should organize into mesoscale systems and some supercells, capable of producing severe gusts and isolated large hail. In a small region, more than 400 J/kg SRH will overlap with strong LLS and some instability. Isolated tornadoes, even a strong one (F2 - F3), may develop along the western coast of Turkey and the eastern Bosporus region. Limited instability and a small area with good conditions for severe weather will result in a level-one threat.
After the first upper level disturbance has passed the region, another strong upper vort-max will arrive at southwestern Greece on early Monday morning. Until 06 UTC on Monday, the chances for severe weather will be rather low.
