Storm Forecast
Valid: Tue 09 Dec 2008 06:00 to Wed 10 Dec 2008 06:00 UTC
Issued: Tue 09 Dec 2008 04:41
Forecaster: VAN DER VELDE

SYNOPSIS

Low pressure and unstable conditions prevail over the western Mediterranean Sea. In the northern flow to the east of an Atlantic high pressure area, advection of cold airmass leads to wintry showers. Occasional thunder is possible around southwestern Norway where a cut-off upper low drifts southward, low chances exist for the English Channel region through Denmark.

DISCUSSION

...northern Mediterranean...

A marginal level 1 is issued as significant values of SREH (250-500 m2/s2) occur at the leading edge of the unstable airmass, as a result of warm air advection. If the storms tap from the SREH, they have the potential of becoming supercells. Towards the end of the period the situation appears the most critical as the Italian coast will be affected. Deep layer shear is forecast to reach a moderate 15 m/s, and low level shear (0-1 km) is highest in coastal regions, over Italy this could reach over 15 m/s which is supportive of tornadoes. Marginally large hail may occur as well.