Storm Forecast
Valid: Wed 13 Jan 2016 06:00 to Thu 14 Jan 2016 06:00 UTC
Issued: Wed 13 Jan 2016 22:53
Forecaster: GATZEN

SYNOPSIS / DISCUSSION

Long-wave trough is located across Europe, the polar jet extends from France over the northern Mediterranean and into southern Turkey. Embedded vort-maxima travel eastwards over Turkey, from northern France into Germany, from the Bay of Biscay towards the north-central Mediterranean, and from the northern Atlantic towards the British Isles. Ridging affects the central and east Mediterranean for most of the period. At lower levels, cold maritime air masses spread into western Europe in the wake of a low. Cold air will also affect northern and central Europe. Warmer air masses are advected into the Mediterranean ahead of a cold front that enters Spain and the west Mediterranean late in the period. A strong low-level jet evolves ahead of this cold front and spreads into the Balkans until Friday morning.

Limited low-level moisture is expected to suppress convective activity over northern and eastern Europe. Better moisture is located over France and the North Sea ahead of the approaching cold front that advects drier air into the British Isles and later on in to France. Rich moisture is also located over the west and south Mediterranean.

Lapse rates are poor over the Mediterranean. Weak CAPE may be possible that is released along the cold front late in the period, but warm equilibrium level temperatures will be unfavourable for thunderstorms. Best potential is expected across the central Mediterranean late in the period, but some embedded storms may even form as warm and moist air masses are advected with the strong low-level jet into the Balkans. Excessive rain along the western slopes of the Dinaric mountains will be mostly non-convective, so a level 1 is not issued. Some thunder can be also expected across the North Sea near the vort-max center, where better lapse rates overlap with relatively high moisture. Another region with some thunderstorms is the western British Isles, where some storms can form as the warm sea surface leads to steep low-level lapse rates within the cold air mass.

Marginal instability together with limited forcing will keep severe potential on a low level on Thursday. A level 1 is not issued therefore.