Storm Forecast
Valid: Mon 25 Oct 2010 06:00 to Tue 26 Oct 2010 06:00 UTC
Issued: Sun 24 Oct 2010 15:14
Forecaster: TUSCHY

A level 2 was issued for S-Greece and W-Crete mainly for large to very large hail, severe wind gusts, excessive rainfall and a few tornadoes.

A level 1 was issued for most parts of the east-central Mediterranean mainly for heavy rainfall, isolated large hail and strong to severe wind gusts.

SYNOPSIS and DISCUSSION

A major trough amplifies over Europe and assists in extensive pressure falls over the central Mediterranean. A potent short wave rotates around this trough, moving off the coast of Tunisia during the start of the forecast period towards the northeast. This upper wave induces a gradually developing surface low/open wave, which crosses the Ionian Sea during the forecast.

A strong LLJ ahead of this surface depression, influx of moist air from the south and some upper-level forcing all indicate a potential heavy rainfall event unfolding for the highlighted area, but progressive nature of this event keeps rainfall risk confined. We expect a large mass of convection ongoing already during the morning hours over Sicily, moving towards the east/northeast thereafter. Main attention of this complex will be its southern part, where ~ 1500 J/kg MLCAPE and 20 m/s DLS overlap, so well organized multicells/isolated supercells are forecast. Greece was upgraded due to the impressive veering of the 0-3 km wind field and overlap of modest CAPE/speed shear. Large to isolated very large hail, strong to severe wind gusts, a few tornado events and excessive rainfall accompany severe storms.

The level 1 was expanded well to the north due to the heavy rainfall risk.

Main cyclogenesis over the western Mediterranean may produce scattered thunderstorms during the late night hours, but available BL moisture will be quite meager, so CAPE will be the limiting ingredient. Enhanced 0-3 km CAPE may foster an isolated waterspout event.