Storm Forecast
Valid: Thu 21 Dec 2017 06:00 to Fri 22 Dec 2017 06:00 UTC
Issued: Thu 21 Dec 2017 00:29
Forecaster: GATZEN

A level 1 was issued for the south Mediterranean mainly for excessive rain.

SYNOPSIS / DISCUSSION

Low geopotential extends from eastern Europe to Algeria. A ridge axis to the north will disappear as a north Atlantic trough amplifies into northern and central Europe. It merges to the northern portions of the east-European trough whereas the southern portions form a cut-off across northern Africa. Ahead of the forming cut-off, warm African air spreads into the south Mediterranean, overlapping with rich maritime moisture so that CAPE forms. Cyclogenesis ahead of the cut-off trough leads to quasi-stationary excessive precipitation over the Sea that is partly due to deep moist convection. Most of the convective activity will be to the south of the forecast domain, though.