Storm Forecast
Valid: Sat 05 Dec 2015 06:00 to Sun 06 Dec 2015 06:00 UTC
Issued: Fri 04 Dec 2015 21:45
Forecaster: DAFIS

SYNOPSIS and DISCUSSION

Most of Europe will be under either dry or stable conditions, exception being the West Mediterranean, where an axis of low 500 hPa geopotential stretches from Germany to NE Spain. This shortwave trough contributes to somewhat steeper mid-level lapse rates and surface observations show dewpoints between 11 and 13°C over the area. Some scattered and unorganised DMC is forecast among the areas where some marginal MLCAPE is forecast, which is juxtaposed with DLS under the upper-air cut-off low that will form according to NWP models. Given the rather weak low-level moisture (mixing ratios less than 8 g/kg) and CAPE (less than 300 J/kg), potential of excessive precipitation is too marginal for a level one. Some waterspouts are not ruled out as weakly-sheared updrafts may form over the local convergence zones.

Western Norway, Ireland and the UK will be affected by the strong south-westerly flow with embedded frontal systems through-out the period. During the day, heavy downpours and gale force wind gusts are expected near the centre of a mid-level vort-max, but the convective contribution is very unlikely to issue any threat level.