Storm Forecast
Valid: Mon 05 Nov 2012 06:00 to Tue 06 Nov 2012 06:00 UTC
Issued: Sun 04 Nov 2012 23:54
Forecaster: SCHLENCZEK

A level 1 is issued along the coastal regions of the Adriatic Sea for excessive convective precipitation, severe wind gusts and tornadoes.

SYNOPSIS / DISCUSSION

A baroclinic zone is found along a line from N Morocco via the Balearic Islands towards E Czech and Poland. The associated cold front separates warm and moist air over the Mediterranean from cool polar air over W Europe. At the northeastern tip of the frontal zone, cyclogenesis is expected during Monday, leading to a low pressure system with a minimum SFC pressure around 980 hPa forecast for Tuesday evening. Deep moist convection is not expected with this low pressure system, but isolated severe wind gusts may occur due to the gradient flow.

The setup over the central Mediterranean looks more interesting as strong vertical wind shear overlaps with some hundred J/kg CAPE along an almost stationary frontal boundary. It is well possible that multicellular storms will move onshore and pose a threat of heavy rainfall. This threat is supported by strong LL convergence and high effective PWAT along the entire LVL1 area. Towards the north, the convective fraction of the total precipitation may be questionable but nevertheless, a significant rainfall event is forecast. Low LCL heights as well as enhanced 150 - 200 m²/s² SRH3 plus locally > 10 m/s LL shear may also allow an isolated tornado event, especially near the coastline. Strong winds at lower levels may also lead to some severe wind gusts. The highest threat of severe convective weather will move across the LVL1 from NW to SE during the day and will reach Albania in the evening hours.

In the wake of the cold front, some low-end instability is forecast over parts of France and Benelux during the late morning and afternoon hours. Due to very low LCL heights and weak background winds, a slight chance of spout-type tornadoes will exist.