Storm Forecast
Valid: Thu 05 Nov 2015 06:00 to Fri 06 Nov 2015 06:00 UTC
Issued: Thu 05 Nov 2015 06:02
Forecaster: GATZEN

SYNOPSIS and DISCUSSION

Weak mid-level flow is present across Europe. A broad but weak trough has entered the western and central Mediterranean. It will slowly move east and weakens further. It is connected to a more intense short-wave trough that crosses central Europe today. Nevertheless, the broad ridge remains from eastern Europe to the North Sea. The weather situation will change at the end of the forecast period, when a strong mid-level jet enters Europe from the west.

At lower levels, weak lapse rates and limited low-level moisture are dominant. Best moisture can be found across the Atlantic Ocean west of Iberia, spreading into the Bay of Biscay ahead of the new Atlantic trough and associated jet stream. Stable lapse rates at the anticyclonically sheared flank of this jet will not allow for deep moist convection.

Better chances are expected across the central Mediterranean. Latest soundings indicate steep low-level lapse rates at around 800 hPa and rich moisture at low levels of 12 g/kg. This allows for CAPE in the order of 500 J/kg. Both decreasing moisture from the north and mid-level ridging from the west will lead to weakening CAPE during the day, and thunderstorms that are actually ongoing are forecast to spread south-east and weaken. Given weak vertical wind shear, organized thunderstorms are not forecast. Main threat will be waterspouts with the main potential in the morning hours.