Storm Forecast
Valid: Wed 28 Oct 2009 06:00 to Thu 29 Oct 2009 06:00 UTC
Issued: Tue 27 Oct 2009 19:23
Forecaster: TUSCHY

SYNOPSIS

Anticyclonic flow covers SW Europe. Active pattern offshore - over the NE Atlantic - causes periodically batches of enhanced WAA, carrying the ridge and keep it more or less stationary during the forecast. A sharp trough over Scotland during the morning hours decays thereafter as geopotential heights increase downstream of an approaching depression. Meanwhile, a deep trough digs southwards over N/E-Europe and causes the advection of cold air at all levels. A weak trough over the south-central Mediterranean moves to the south while gradually degenerating.

DISCUSSION

... Ukraine ...

A cold front crosses the Ukraine from NW to SE during the forecast as a strong mid-level streak is placed over Poland/SW Ukraine. This constellation is favorable for upper divergence with augmented convective chances during the day. Despite the fact that moisture pooling along the front remains marginal at best, showers/isolated thunderstorms are possible. No significant wind maximum at lower levels is forecast and hence, isolated severe wind gusts are possible but too limited for a level 1. Marginal hail risk is present as WBZ continues to decrease. Overall risk elapses during the early evening hours as BL becomes more stable.

... SE / E Mediterranean ...

Scattered showers/thunderstorms occur beneath weakening trough. Shear remains weak but modest CAPE could cause marginal hail and strong wind gusts. Best LL CAPE is displaced to the south/east of our forecast area, so overall funnel/waterspout risk remains low.

A concern is the SW coast of Turkey, where slow moving convection could locally cause augmented rain amounts, but weak winds below 3km and hence limited inflow strength keep this risk below the level 1 threshold.