Storm Forecast
Valid: Sun 31 Oct 2010 06:00 to Mon 01 Nov 2010 06:00 UTC
Issued: Sun 31 Oct 2010 05:48
Forecaster: SCHLENCZEK

A level 1 was issued for E Spain and the W Mediterranean mainly for severe wind gusts and to a lesser extent for tornadoes.

A level 1 was issued for S France and most parts of Italy mainly for excessive rainfall and to a lesser extent for severe wind gusts.

A level 1 was issued for Corsica, Sardinia and NW to S-central Italy for excessive rainfall, severe wind gusts and tornadoes.

SYNOPSIS / DISCUSSION

Between high pressure over the eastern parts of Europe and a low pressure system over the British Isles, a strong (south-) westerly upper level flow has established over the W Mediterranean. In the wake of the trough, showers and thunderstorms are likely to occur but weak directional shear and speed shear should preclude severe weather.

At this moment, GFS suggests a chance for isolated severe weather over E Spain and the Balearic Islands where some hundred J/kg CAPE and 20 - 30 m/s deep layer shear tend to overlap. Strong LL shear and low LCL heights combined with low CIN over the W Mediterranean may allow an isolated tornado event but the main risk should be severe wind gusts due to strong 20 - 25 m/s winds at 850 hPa.

The cold front associated with a developing surface low over the Gulf of Lion is not very strong but due to high amounts of effective precipitable water, excessive rainfall is expected in a broad area from S France to NE Italy. Especially a small region between S-central Italy and Sardinia may get an enhanced tornado risk as SRH, LLS and BL moisture are favourable for tornadoes but due to the limited amount of CAPE, overall risk should be below the level 2 threshold.