Storm Forecast
Valid: Tue 10 Jan 2012 06:00 to Wed 11 Jan 2012 06:00 UTC
Issued: Mon 09 Jan 2012 20:44
Forecaster: TUSCHY

SYNOPSIS and DISCUSSION

There is not much change to talk about compared to the past 24 hours. A quasi-stationary longwave trough stalls over E/SE Europe with a weak surface depression along its SE fringe, leaving Crete to the east. A more zonal flow pattern evolves over NW Europe with strong CAA north of Ireland and Scotland. For SW/CNTRL Europe, the high pressure dominates and suppresses any deeper convection.

During the morning hours, scattered showers and thunderstorms are still forecast just east of Crete. The surface depression shifts slowly eastwards. The attendant cold front gradually speeds up until noon and abandons our forecast area to the E/SE. We expanded the thunderstorm area northwards to cover sporadic initiation in the postfrontal, cold air mass. We did not add the Aegean Sea, as some fetch length is needed for adequate BL moisture recovery.

Another cold upper low enters the Adriatic Sea around noon and the Tyrrhenian Sea after 18 Z. Beneath that feature, isolated thunderstorms are forecast. The BL flow is weaker compared to yesterday, so conditions may become more conducive for waterspout development. However only marginal LL CAPE build-up is forecast, which precludes the issuance of a level 1. Sleet and marginal hail will be the primary risk.

Further north /east of Iceland/ a deepening low travels from Iceland to the ENE to NE with very cold mid-level temperatures advecting eastwards. SSTs of 5-7°C well offshore, up to 9°C near the Norwegian coast and 500 hPa temperatures below -40°C assist in enough temperature spread for deep convection....also fostered by cold EL temperatures. Scattered thunderstorms are forecast with a rare 50-% probability thunderstorm area that far to the north. Main risk will be severe wind gusts with winds of 20-25 m/s at 850 hPa.