Storm Forecast
Valid: Sun 23 Dec 2007 06:00 to Mon 24 Dec 2007 06:00 UTC
Issued: Sat 22 Dec 2007 19:35
Forecaster: DAHL

SYNOPSIS

Residual quasi-stationary large-scale upper trough is covering SW Europe and the W Mediterranean, with weak DCVA at its eastern periphery, maintaining a weak cyclonic circulation at the surface over the W Mediterranean and the Maghreb States. The main, meandering upper frontal zone is stretching from the N Atlantic across N Europe, with a small cut-off cyclone expected to develop over N Germany on Sunday afternoon. An imbedded Atlantic longwave trough is slowly making progress towards Europe, so that the attendant extensive Atlantic SFC low complex will as well spread into W and N Europe during the period. Exensive/cold high-pressure area keeps sprawling across the eastern half of Europe.

DISCUSSION

... western Mediterranean ...

Weakly unstable profiles should persist over the W Mediterranean ... and scattered to widespread thunderstorms are anticipated. Though kinematic/thermodynamic profiles will largely be quite unimpressive, GFS does hint at moderately strong LLS over Sicily and the S Tyrrhenian Sea. The storms will likely fall apart as they make landfall, but especially near the coasts, convection should benefit from the enhanced LLS ... and a brief spin-up of a tornado or two cannot be ruled out, especially as LCL height will likely be quite low. However, the cells themselves are unlikely to be particularly long-lived and intense given weak CAPE/DLS, and the allover threat for severe weather is likely to remain below level-one thresholds.