Storm Forecast
Valid: Fri 26 Nov 2010 06:00 to Sat 27 Nov 2010 06:00 UTC
Issued: Thu 25 Nov 2010 15:32
Forecaster: TUSCHY

A level 1 was issued for an area west of the Strait of Gibraltar mainly for heavy rainfall.

A level 1 was issued for the east coast of the Adriatic Sea and parts of the Ionian Sea mainly for heavy rainfall.

A level 1 was issued for the NE Aegean Sea mainly for heavy rainfall.

SYNOPSIS and DISCUSSION

A cold and extensive upper trough is placed over Europe, assisting in the advection of a cold and dry air mass, which covers all of Europe (beside the southern most parts). Any convective activity will be bound either to some moisture source (oceans) or to spots where a combination of favorable diurnal heating, some BL moisture and very cold mid-levels exist.

The central Mediterranean will see an active day with widespread showers and isolated to scattered thunderstorms with a gradually developing depression. With some moisture advection from the south, modest CAPE may build up over the Tyrrhenian Sea, the Ionian Sea and the Adriatic Sea. Despite CAA atop warm SSTs of the Mediterranean (some LL CAPE forecast), LL wind field starts to respond to the strengthening depression over Italy with increasing shear throughout the day. That's not the best environment for long-lived/well structured convergence zones and an attendant waterspout risk. Nevertheless an isolated event can't be ruled out. Heavy rain accompanies that activity along coastal areas, especially along the east coast of the Adriatic and Ionian Sea.

We went with a level 1 for heavy rainfall over the NE Aegean Sea with repeatedly developing thunderstorms. The same for the Strait of Gibraltar and to the west.

Otherwise, an extensive low probability thunderstorm area was issued for a few short-lived thunderstorms over parts of NW Europe.