Valid: Mon 17 Dec 2012 06:00 to Tue 18 Dec 2012 06:00 UTC
Issued: Sun 16 Dec 2012 22:55
A level 1 was issued for W France mainly for isolated severe wind gusts and tornadoes.
SYNOPSIS / DISCUSSION
Low geopotential heights are present in most parts of western and S-central Europe and a strong WNWerly jet stream stretches from W France to W Turkey. Most of the convection will occur in the vicinity of the upper low centers over the British Isles and over the Tyrrhenian and Adriatic Sea. Due to low LCL heights, strong (locally > 15 m/s) 0-1 km shear, augmented SRH and approx. 20 m/s background flow at 850 hPa, both tornadoes and severe wind gusts may occur in the coastal regions of W France.
Ahead of the low pressure system which will affect Turkey, strong 20 - 25 m/s deep layer shear and some hundred J/kg CAPE are in place. Some of the storms could become organized and may produce isolated severe wind gusts but the overall threat is too low for a LVL1.