VALID 06Z FRI 15/11 - 06Z SAT 16/11 2002
ISSUED: 15/11 00:01Z
FORECASTER: GROENEMEIJER

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN ITALY, SOUTHEASTERN FRANCE AND THE WESTERN MEDITERRENEAN

GENERAL THUNDERSTORMS ARE FORECAST ACROSS PARTS OF THE BRITISH ISLES, FRANCE, THE IBERIC PENINSULA, THE WESTERN MEDITERRANEAN INCLUDING THE ADRIATIC.

SYNOPSIS

A DEEP TROUGH IS LOCATED OVER WESTERN EUROPE WITH ITS BASE OVER THE IBERIAN PENINSULA. BAROCLINIC WAVES ARE TRAVELLING ALONG JET ON SOUTHEASTERN FLANK OF THIS SYSTEM. THE AIR MASS OVER THE WESTERN MEDITERRANEAN IS MARGINALLY UNSTABLE.

DISCUSSION

...WESTERN MEDITERRANEAN, SOUTHEASTERN FRANCE, NORTHERN ITALY...
NEW BAROCLINIC WAVE DEVELOPING IS EXPECTED TO FORM DURING THE AFTERNOON OVER THE WESTERN MEDITERRENEAN. STRONG DIRECTIONAL AND SPEED SHEAR IN THE LOWER LEVELS WILL RESULT IN HIGH 0-3KM S.R.HELICITY IN WARM ADVECTION REGIME ON EASTERN AND NORTHEASTERN FLANK OF THE SYSTEM. LIMITING FACTOR TO THIS SEVERE EVENT IS INSTABILITY. CAPE WILL GENERALLY BE LESS THAN 600 J/KG. GIVE HIGH HELICITY VALUES A TORNADO OR TWO MAY OCCUR, THOUGH MAIN THREAT WILL BE STRONG /UP TO 65 KT/ GUSTS.

...SOUTHERN ALPINE REGION...
STRONG UPSLOPE WINDS AND ADVECTION OF WARM MOIST AIR IN COMBINATION WITH LOW STABILITY WILL CAUSE VERY HIGH RAINFALL AMOUNTS TO ACCUMULATE DURING THE WHOLE OF THE FORECAST PERIOD. SOME FLOODING PROBLEMS ARE LIKELY.

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