Storm Forecast
Valid: Tue 23 Oct 2012 06:00 to Wed 24 Oct 2012 06:00 UTC
Issued: Mon 22 Oct 2012 22:01
Forecaster: KOROSEC

A level 1 was issued for W-CNTRL Mediterranean mainly for excessive rain, marginal hail/wind threat and a waterspout threat.

A level 1 was issued for Portugal mainly for intense rain, strong to severe winds and tornado threat.

SYNOPSIS

High over low pattern across much of Europe on Tuesday, with an extensive ridge extending towards north-central and western Europe, while a shallow upper low wobbles over western Mediterranean sea. Another upper low is west of Iberia, slowly progressing east with a frontal system. The third upper low is located over SE Europe.

DISCUSSION

... W-CNTRL Mediterranean and SE Europe ...

Two upper lows will be a focus activity in the Mediterranean and scattered showers and thunderstorms are expected. The lack of wind shear precludes organized storms, although locally some slow moving cells could spark flash floods threat. Positive SSTs of Mediterranean sea will support high dewpoints and therefore moderate instability. Locally even high LLCAPE, which could support waterspout-type tornadoes.

... SW Iberia / Portugal ...

A large upper low slowly approaches from the west where activity seems likely along the cold front. Rather impressive shear profiles and quite warm sea temp should maintain strong WAA with SSW-erly LLJ towards Iberia. Once the front pushes through (this seems limited to 2nd half of the forecast period and overnight to WEdnesday), storms should also fire near Portugal coastal areas and slightly inland. A level 1 seems warranted given the conditions in place, as storms will be capable of producing a excessive rain and strong/severe winds and even a tornado, given the good veering winds with height in the lowest levels.