Storm Forecast
Valid: Thu 14 Dec 2017 06:00 to Fri 15 Dec 2017 06:00 UTC
Issued: Thu 14 Dec 2017 00:14
Forecaster: GATZEN

SYNOPSIS / DISCUSSION

A European long-wave trough expands from western to central Europe and also amplifies into the north Mediterranean. A strong mid-level jet curves around its southern flank, and several vort-maxima travel eastward. A deeply-mixed polar air mass spreads across much of western and central Europe. Steep lapse rates are expected within this air mass party due to stretching and partly due to a history of low-level warming over the sea surface. Although low-level moisture is limited, some weak CAPE is expected by latest models that show skinny CAPE profiles but EL temperatures below -20°C over large regions. Showers are expected to form that may also produce thunder. Greatest potential is expected below the cyclonically sheared flank of the mid-level jet. Given the weak CAPE, severe storms are not expected. However, severe wind gusts can occur that are mostly due to the strong large-scale pressure gradient.

Over the Mediterranean, also CAPE is expected to form due to better low-level moisture overlapping with low-level steep lapse rates. EL temperatures will mostly stay warmer than -20°C, however, a few storms are not ruled out late in the period. Although vertical wind shear is strong, favourably veering profiles are not expected. Severe weather is forecast to be rather unlikely although severe wind gusts can occur.