Storm Forecast
Valid: Tue 02 Feb 2010 06:00 to Wed 03 Feb 2010 06:00 UTC
Issued: Tue 02 Feb 2010 00:46
Forecaster: KOROSEC

A level 1 was issued for WSW Turkey and southern Aegean Sea mainly for large hail, severe wind gusts, excessive rainfall and isolated tornadoes.

SYNOPSIS

A sharp trough with well defined frontal system over North Sea moves towards SE where deep surface depression takes place over Denmark (central pressure near 985hPa). Polar airmass overspreads the North Sea with quite steep mid level lapse rates. Shallow convection seems likely, mostly over the sea. However, as the front rapidly shifts SE-wards, locally strong winds will be possible.

Over SE Europe/eastern Mediterranean sea, a powerful trough exits our forecast area during the late morning hours and moves eastwards. The rest of Europe stays cool/cold and stable.

An interesting low pressure system with some characteristics of a tropical (subtropical) storm has developed over 1-2°C warmer SSTs off the coast of Africa during the last days and was already in effect over Canary Islands yesterday. The system is expected to move NE-wards towards extreme SW-ern Iberian Peninsula, affecting southern Portugal by Wednesday morning. Deep convection with heavy rain and strong winds episodes can be expected around the main vortex, but as it stays mostly over the open waters, a threat level was not issued.

... WSW Turkey and southern Aegean Sea ...

A quite powerful trough and frontal system, which was in effect during the previous day/night, slowly moves eastwards across southern Turkey. In the morning hours, storms activity will be still on going from southern Aegean Sea towards SW Turkish coast. A well pronounced surface front will be the main focus for deep convection placed under the left jet exit region, where strong QG forcing will support rather robust environment. Near 20m/s of deep layer shear will be in place across the warm sector ahead of the front, overlaping with moderate MLCAPE. A few well organized multicells and supercells should form as well. There, threat for large hail, strong winds and an isolated tornado or two will be possible, given the high LL shear/SREH up to 15m/s, enhanced especially along the SW Turkish coast. A cluster of storms is possible as well, which could allow additional convective rainfall threat inland into W Turkey. In combination of persisting SW flow ahead of the front, models do agree that a flash flood risk exists. Later during the day, activity will be moving east along the frontal system and along the southern Turkish coast, where similar conditions will favor severe storms as well.

Behind the system, a very steep lapse rates (near or below -35°C at 500hPa) overspreads Aegean sea which should allow numerous isolated showers and thunderstorms to form. A couple of waterspouts will be possible given the quite high LL CAPE in place and only weak winds behind the front.