Storm Forecast
Valid: Thu 05 Oct 2006 07:00 to Fri 06 Oct 2006 06:00 UTC
Issued: Thu 05 Oct 2006 07:02
Forecaster: GATZEN

SYNOPSIS

Weakening trough over western/central Mediterranean becomes narrow as subtropic Atlantic high ridges into western Europe. While last strong jet streak travels northward over Balkans ... rather weak jet streaks are expected to curve around the periphery of the long-wave trough today ... yielding some DCVA. At the eastern flank of the trough ... a frontal boundary remains quasistationary ... with very warm African air mass spreading into Black Sea and southern Ukraine. Soundings do indicate that well-developed EML is not present in the range of this air mass any more ... and given dry boundary-layer ... CAPE is not expected over a broad region. To the west ... EML is present in the range of the frontal boundary over southern Italy ... and given rich low-level moisture, rather high CAPE was present. Further west ... long-wave trough is filled with cool air mass ... and latest soundings indicate steep low-level lapse rates and locally strong low-level buoyancy. Another focus of expected convective acticity is a short-wave that travels eastward over Denmark today.

DISCUSSION

Sicily, southern Italy, south-western Balkans

In the range of the frontal boundary ... quite high instability can be expected today ... indicated by latest soundings showing steep mid-level lapse rates and rich boundary-layer moisture. Surface cold-front has moved quite far eastward leading to low-level convergence east of the upper jet ... and given rather weak vertical wind shear ... expect that thunderstorms that form will be non-severe. Intense precip is likely, though. However ... storms that form west of the surface cold front will be affected by strong DLS in the range of the jet. Given westerly surface winds ... SRH seems to be not favorable for mesocyclones. Best potential exist during the next couple of hours in the range of southern Adriatic. In the afternoon, threat is expected to weaken.

Northern Mediterranean

In the range of the trough axis ... steep low-level lapse rates and locally strong low-level buoyancy is likely. While low-level northerly winds are quite strong over western Mediterranean ... weak winds are forecast over northern Italy ... where chance for a few waterspouts is expected to be slightly higher. However ... only isolated events are expected ATTM ... and a level 1 is not forecast.

Denmark

A weak upper trough travels eastward over southern North Sea /Baltic Sea today ... yielding DCVA. Affected air mass is rather unstable as indicated by latest soundings due to steep low-level lapse rates and rather moist boundary-layer. In the range of the trough ... cool mid-levels are expected ... and CAPE should reach about 100 J/kg locally. Expect that thunderstorms form during the day moving eastward over southern North Sea, Denmark, and southern Baltic Sea. As vertical wind shear is quite weak ... severe thunderstorms are not likely. However ... a jet streak spreads eastward in the wake of the trough ... and increasing vertical wind shear and QG forcing is forecast during the afternoon hours ... and an isolated wind event is not ruled out with the stronger storms.