Storm Forecast
Valid: Sun 09 Dec 2012 06:00 to Mon 10 Dec 2012 06:00 UTC
Issued: Sun 09 Dec 2012 05:58
Forecaster: VAN DER VELDE

A level 1 was issued for western Turkey mainly for local excessive precipitation.

A level 1 was issued for western Greece, Albania and Ionian Sea for waterspout type tornadoes.

SYNOPSIS

A strong northerly flow advects arctic unstable air deep into Europe. Two low pressure areas are the focus for convection. The first moves from the Shetland Islands to eastern Germany and has strong pressure gradients over the western and southern North Sea. Initially a warm front lies over Germany and a cold front will reach the Netherlands around 12Z, occluding. The cold unstable air will move into Germany but is likely not so active over land. Its mid level cold front could trigger some isolated lightning mainly in the Alps during early Monday morning.
The second low dwells around Greece and Turkey with cold air advection over the warm Mediterranean over Italy and a plume of warmer unstable air being advected for quite a long time into southern Greece, Bulgaria and western Turkey, especially, where large 0-2 km convergence signals are produced in GFS, Vertical wind shear where it overlaps with CAPE seems to be moderate and at low levels only enhanced by friction over land. This seems not sufficient for tornadoes although an isolated one cannot be ruled out. The airmass is not quite humid enough to cause a high precipitation efficiency in storms, but backbuilding storms will likely produce local excessive rain events, best chances in the south of the level 1 area. Another level 1 was drawn for western Greece, Albania and Ionian Sea for waterspout type tornadoes. This potential exists due to steep low level lapse rates and a slow storm motion environment close to the center of the mid level cold pool.