Storm Forecast
Valid: Wed 23 Jan 2008 06:00 to Thu 24 Jan 2008 06:00 UTC
Issued: Tue 22 Jan 2008 18:57
Forecaster: GATZEN

SYNOPSIS

Subtropical ridge over western Europe evades into Central Europe. To the north-west, intense long-wave trough over the northern Atlantic propagates eastward into Scandinavia. Over east Mediterranean, an amplified upper trough is present. At lower levels, cold and dry air mass over Europe spreads into central, and eastern Mediterranean, while warm air mass is advected into Iberian Peninsula and British Isles. West of a cold front that is expected to reach the British Isles at the end of the forecast period, an air mass characterized by neutral lapse rates and relatively rich boundary-layer moisture is expected in the range of the Atlantic trough.

DISCUSSION

Greece region/Aegean

Amplified upper trough moves into east Mediterranean. QG forcing is expected as a mid-level southerly jet streak curves around the troughs base. However, it seems to be quite questionable that instability will really develop. Current thinking is that more stratiform clouds will develop in response to large scale lift, while embedded convection will be elevated mostly. Best chances for surface-based thunderstorms seems to exist over southern Aegean, where models indicate rather rich low-level moisture. Intense precipitation is expected, while chance for severe convection seems to be rather low.

Northwest British Isles

Along the frontal boundary that reaches north-west British Isles late in the period, strong vertical wind shear is forecast. However, instability is rather questionable, but will not rule out a few embedded tornadoes along the leading gust front. Chance seems to be relatively weak, but will include a level 1 along the cold front where tornadoes seem to be most likely due to model-based CAPE on Thursday morning. At the end of the period, unstable maritime air mass in the range of the trough will affect the north-western regions, and thunderstorms are expected. Given moderate to strong vertical wind shear, a few severe wind gusts are not ruled out in the range of the thunderstorms, but overall threat is expected to be too low for a level 1.