Storm Forecast
Valid: Sat 20 Dec 2008 06:00 to Sun 21 Dec 2008 06:00 UTC
Issued: Fri 19 Dec 2008 22:11
Forecaster: DAHL

SYNOPSIS

Strong upper westerlies are stretching across the N Atlantic and via Scandinavia into extreme N Russia, which an upper-low complex persisting over the central Mediterranean and the Balkans. During the period, a trough imbedded in the northern westerly flow will phase with the SE European system, resulting in a deep/intense northwesterly flow from the North Sea into the southern Mediterranean by the end of the peroid. At low levels, a weakening -- though initially quite intense -- SFC low will move from S Scandinavia into the Baltic Sea, while a sturdy/deep high-pressure area persists over the western half of Europe.

DISCUSSION

... central Mediterranean ... Aegean region ... Turkey ... southern Black Sea ...

It seems that the only focus for scattered lightning will exist over the Ionian/Aegen regions in a virtually neutrally stratified air mass. Some 20 m/s DLS are simulated over the very southeastern extension of the unstable air mass, though slightly offset from the region where convection will be deepest. This seems to limit the severe threat ... though an isolated marginally severe hail/wind event or two could occur. Also, a slight threat for waterspouts exists given rather steep low-level lapse rates and a nearly saturated maritime boundary layer. However, the severe threat does not seem to be robust enough for a categorical outlook.

... N Germany ... Denmark ...

Along the cold front of the Scandinavian low-pressure system, a narrow line of shallow convection may occur in a region of strong mesoscale ascent. This activity will mainly affect N Germany and Denmark early on Saturday. Current indications are that EL's will be too warm for appreciable lightning activity. However, expect local augmentations of the low-level winds in association with this line. The severe threat should be too low for the introduction of a threat area.