Storm Forecast
Valid: Thu 02 Jan 2014 06:00 to Fri 03 Jan 2014 06:00 UTC
Issued: Wed 01 Jan 2014 23:41
Forecaster: GATZEN

SYNOPSIS / DISCUSSION

A weak long-wave trough is situated across eastern Europe. Along the southern edge, a short-wave trough is situated across Turkey and will travel east during the period. Rather cool and dry air masses dominate the continental regions, whereas better boundary-layer moisture is located across the Mediterranean Sea. Steep lapse rates are mostly limited to a shallow layer above the sea surface, but latest Thessaloniki ascend indicates the chance of at least weak CAPE near the troughs base. Weak vertical wind shear limits the storm organization and severe storms are not likely although convection can contribute to the threat of excessive precipitation locally. Additionally, waterspouts may develop with the best potential across the Aegean Sea on Thursday morning.

Across western Europe, a new intensification of the northern Atlantic cyclonic activity is increasingly affecting the flow. A short-wave trough will move east across Germany during the day. In its wake, a strong mid-level jet streak will spread into the British Isles and an intense low pressure system will move to a position to the north of Ireland. The cold front of the storm will be located ahead of the following jet streak and reaches the North Sea soon after midnight. Therefore, only shallow instability is expected in the warm air mass of the low-level jet ahead of the cold front, and thunderstorms are not likely. A weak tornado is not ruled out in the range of the narrow cold frontal rain band due to the strong low-level vertical wind shear. In the wake of the cold front, rather dry air masses will limit the potential of thunderstorms. A few storms may develop, but the contribution of deep moist convection to the occurrence of severe wind gusts is expected to be weak.