Storm Forecast
Valid: Thu 08 Jan 2009 06:00 to Fri 09 Jan 2009 06:00 UTC
Issued: Wed 07 Jan 2009 19:10
Forecaster: GATZEN

SYNOPSIS

Europe is dominated by cold air masses that spread into south-western Europe and western Mediterranean in the range of a developing cut-off low centered over the Iberian Peninsula and north-easterly low-level winds at the southern flank of a central European high. To the south-east of the cut-off low, a south-westerly jet is present over northern Africa that spreads across the southern and eastern Mediterranean Sea.

DISCUSSION

Mediterranean

A rather weak short-wave trough moves north-eastward into southern Mediterranean associated with some lift across the central Mediterranean. At lower levels, a low pressure system located over Tunisia will be associated with some warm air advection into the central Mediterranean.

The warm air mass is characterized by rather steep lapse rates in the lowest 2 km, while boundary-layer moisture over the sea has reached about 6-7 g/kg. Latest soundings already indicate weak CAPE and thunderstorms were also detected.

On Thursday, weak instability seems to be likely over the central Mediterranean. Given weak lift in the range of the upper trough as well as low-level convergence in the range of the frontal boundary moving northward during the period, convection will likely develop. EL temperatures are expected to be cold enough, and thunderstorms are forecast. Given weak instability. low-level convergence and only moderate vertical wind shear, severe thunderstorms are not forecast. Later in the period, more thunderstorms are possible further west given some low-level warm air advection with easterly surface winds, but low-level moisture seem to be rather weak, and thunderstorms are not that likely as over the central Mediterranean.