Storm Forecast
Valid: Thu 19 Feb 2009 06:00 to Fri 20 Feb 2009 06:00 UTC
Issued: Wed 18 Feb 2009 19:34
Forecaster: GATZEN

SYNOPSIS

A trough covers central and eastern Europe, where cold air masses are present and chances for thunderstorms are pretty low. Along the southern flank of this trough, a strong jet streak is present over the Mediterranean that points towards the southern Aegean. Over western Europe, the ridge of an Atlantic high leads to the advection of mild maritime air masses.

DISCUSSION

Southern Aegean to southern Turkey

A strong jet streak moving across the Mediterranean will provide some DCVA across the central Aegean. At low levels, the model guidance and also the latest surface observations indicate that rather moist air masses will advect northward, and QG forcing is likely over the central Aegean. A surface low is predicted to intensify over this region, its cold front will likely cross the Aegean Sea until noon and will go on into southern Turkey in the afternoon and evening hours.

Focus of convective activity is the warm air mass just ahead of this cold front. With low-level lapse rates of 8K/km between 2 and 4 km and surface dewpoints around 10°C, models indicate an EL temperature of -30°C. Weak CIN and quite strong low-level forcing along the cold front will likely assist convective development, and thunderstorms are forecast.

Moderate deep layer vertical wind shear will likely lead to organization along the cold front, a line of convection is likely. Best potential for some linear segments with strong wind gusts is expected in the southern portions, where deep layer vertical wind shear is strongest. Later in the period, convection will spread into Turkey, where severe potential is expected to remain rather weak, although a tornado is not ruled out given some veering winds along the coast ahead of the front as well as quite rich low-level moisture and associated low-level buoyancy.