CONVECTIVE FORECAST
VALID 06Z SUN 28/11 - 06Z MON 29/11 2004
ISSUED: 27/11 20:55Z
FORECASTER: DAHL

General thunderstorms are forecast across the central Mediterranean Sea including the Aegean Sea.

General thunderstorms are forecast across extreme W Portugal.

SYNOPSIS

Broad WNWLY upper flow persisting across Europe ... with two embedded short-wave troughs expected over the central Mediterranean Sea and over the UK respectively by Sunday morning. The latter trough is progged to close off into an upper cut-off low over France late in the period. Another upper cut-off low is lingering W of the Iberian Atlantic coast.

DISCUSSION

...central Mediterranean regions...
TSTMS will likely continue ahead of the Mediterranean vort max ... BL air mass is nearly saturated ... with quite low LFC heights ... so that a few waterspouts could occur. Deep-layer shear is progged to weaken during the day ... with shear magnitudes being too small for organized severe TSTM threat.

...W Portugal...
Convection ahead of the Atlantic cut-off low will likely persist ... and may spread into W Portugal during the day. MM5 progs a narrow band of enhanced low-level shear over W Portugal ... and TSTMS developing in this environment may acquire rotation and pose a severe threat. However ... threat is too uncertain for a categorical risk ATTM.

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