Storm Forecast
Valid: Thu 09 Nov 2006 13:00 to Fri 10 Nov 2006 06:00 UTC
Issued: Thu 09 Nov 2006 13:19
Forecaster: DAHL

SYNOPSIS

Strongly meandering and intense upper NWLY flow has established across the N Atlantic and Europe ... with a trough currently over central Europe ... digging into the N Balkans towards the end of the FCST period. Associated SFC cold front should extend from central France across S Germay towards the W Belarus by 18Z ... merging with the SFC low which is tracking from N Poland into W-central Russia during the remainder of the FCST period.

DISCUSSION

...North Sea ... Germany ... Poland ...

Strong NWLY flow is advecting mixed polar air into central portions of Europe in the wake of the cold front ... having resulted in cellular convection which is now mainly affecting the North Sea and Germany. Though shear profiles are quite strong ... relatively shallow nature of the convection ... and lack of mesoscale focus for ascent seem to limit severe threat. Nonetheless ... an isolated severe wind gusts ... and maybe even a brief funnel cloud or a tornado could occur given low LCLs and strong LLS. However ... chances are rather low and a categorical risk is not necessary. Indications are that convection will continue to be only weakly electrified ... and will thus refrain from issuing a TSTM forecast as well.

... N Adriatic Sea ... Tyrrhenian Sea ...

Weak CAPE is expected to develop in the lee of the Alps over the N Adriatic Sea. As strong DCVA-forced ascent should be in place ... expect a couple of TSTMS to develop in the 00Z to 06Z time frame. TSTMS may even spread across the Tyrrhenian Sea early Friday morning. LLS should be rather weak ... but about 20 m/s DLS may support isolated severe TSTMS. It does not seem that coverage of TSTMS will be very large based on QPF fields ... maybe tied to lack of strong low-level mesoscale ascent. Will thus not introduce a level one ATTM.