Storm Forecast
Valid: Mon 13 Oct 2008 06:00 to Tue 14 Oct 2008 06:00 UTC
Issued: Sun 12 Oct 2008 17:39
Forecaster: DAHL

SYNOPSIS

Weakly defined omega flow pattern persists over S Europe at mid/upper levels while strong, meandering zonal flow is present over the N Atlantic and the northern parts of Europe. Ahead of an imbedded upper trough, a frontal wave will travel from S Norway into the Baltics during the period. Ahead of the associated cold front, low level warm advection will be present across much of central Europe. Quiescent synoptic conditions will prevail over the southern parts of Europe.

DISCUSSION

... Portugal ... Spain ... France ... S Benelux ... W Germany ... Switzerland ... extreme NW Italy ...

Scattered thunderstorms are likely to develop amidst plume of weakly capped subtropical air in a strip from Iberia across France into Germany. CAPE should be quite weak and current model guidance suggests that shear will be quite modest also, suggesting that severe evolution is unlikely. Towards N Germany and Poland, cloud tops should be rather shallow with EL temperatures of about -20°C, and lightning may be too sporadinc for an inclusion of these regions in a thunderstorm forecast area.

Strongest kinematic fields will likely exist over S Spain with about 15 m/s DLS, which may suffice for an isolated marginally severe hail/wind wvent, but threat should be too low to necessitate a categorical risk.