Storm Forecast
Valid: Sun 14 Jan 2007 06:00 to Mon 15 Jan 2007 06:00 UTC
Issued: Sat 13 Jan 2007 21:04
Forecaster: DAHL

SYNOPSIS

Progressive upper flow pattern continues, with upper trough digging from north central Europe into the Ukraine/Black-Sea region during the period. Upstream perturbation will affect the N British Isles, the northern North Sea and central parts of W Norway late Sunday evening/night. Both upper features are accompanied by seasonably strong SFC low-pressure systems.

DISCUSSION

... Germany ... Poland ... Baltic States ... Belarus ...

Convective scenario remains utterly challenging to predict. GFS 700 hPa LIs remain positive in the subtropical air mass advecting northwards E of the central-European upper trough. However, potential instability will exist ahead of and along the cold front per GFS, and the question of the day will be whether or not CAPE will develop. As of Saturday evening, significant convection failed to form along the front despite the GFS simulating weak potential instability in the presence of strong forcing for upward motion. Will thus not introduce a categorical risk ATTM, but the cold front should be monitored for possible convective development. Shear remains very favorable for severe outflow winds as well as shallow mesocyclones.

... western Norway ...

Similar scenario may be expected with the next perturbation affecting W Norway late in the period. It seems that especially in the upslope flow regime at the Norwegian W coast, scattered TSTMS may occur. This convection could augment the already severe back-ground flow. However, activity should be too isolated to warrant a categorical risk.