Storm Forecast
Valid: Thu 21 Jan 2010 06:00 to Fri 22 Jan 2010 06:00 UTC
Issued: Wed 20 Jan 2010 17:06
Forecaster: GATZEN

A level 1 was issued for southern Italy and the southern Aegean mainly for severe wnd gusts and excessive precipitation.

SYNOPSIS

To the east of a ridge building over western Europe, a broad and deep polar trough is placed across central and eastern Europe. Along the periphery of this trough, a short-wave trough travels across the central Mediterranean Sea during the period. The associated mid-level jet streak will point into the southern Aegean at the end of the period. At low levels, cold and dry polar air masses dominate most of the forecast region. A tongue of moist low-level air spreads into the Bay of Biscay ahead of new frontal systems over the Atlantic. Rather moist air is also present in the range of a low moving eastward across the central Mediterranean.

DISCUSSION

Southern Mediterranean to southern Aegean

As a short-wave trough amplifies across the central Mediterranean, a surface low is expected to deepen as is moves across southern Italy. Rather strong lift is expected to result in widespread precipitation. In the warm sector of the low, a tongue of rich low-level moisture spreads north-eastward into the Greece region and southern Aegean, where rather cold mid-level temperatures are present. Neutral to slightly unstable lapse rates will likely evolve due to continuing lift in the warm air advection regime. Along the cold front, showers and thunderstorms will likely develop and may organize into a convective line. Given rather strong vertical wind shear, bowing lines are not ruled out, capable of producing severe wind gusts. Additionally, a brief tornado is not ruled out given favorably veering profiles especially across southern Greece in the evening hours. Late in the period, the convective activity spreads into central Greece and southern Turkey, where instability will decrease significantly. Embedded convection will be likely, though, capable of producing excessive rain until the morning hours.