VALID 14Z SAT 09/11 - 06Z SUN 10/11 2002
ISSUED: 09/11 13:57Z
FORECASTER: GATZEN

GENERAL THUNDERSTORMS ARE FORECAST ACROSS EASTERN MEDITERRANEAN

SYNOPSIS

LONG-WAVE TROUGH COVERING MOST OF EUROPE PROPAGATES SLOWLY EASTWARD. NEAR IT'S CENTER, INTENSE SHORT-WAVE TROUGH HAS REACHED NORTHERN CENTRAL EUROPE. ANOTHER SHORT-WAVE TROUGH ROTATING ALONG LONG-WAVE TROUGH'S PERIPHERY IS CROSSING THE EASTERN MEDITERRANEAN.

DISCUSSION

...EASTERN MEDITERRANEAN...
MARITIME POLAR AIRMASS HAS DISPLACED MARITIME SUBTROPICAL AIR OVER EASTERN MEDITERRANEAN ON THE BACK SITE OF A COLD FRONT SITUATED ALONG THE FRONT OF EUROPEAN LONG-WAVE TROUGH. WITHIN NORTHWESTERLY CURRENT SEVERAL VORT-MAX TRAVEL EASTWARD. IN THE RANGE OF THE TROUGH AFFECTED AIRMASS SHOWS QUITE STABLE LAYERING WITH RELATIVELY COLD BOUNDARY LAYER IN COMBINATION WITH CAPPING INVERSION ABOVE 800 HPA. TO THE EAST, WARMER BOUNDARY LAYER IS STILL IN PLACE, WITH STEEP LAPSE RATES IN THE LOWEST KILOMETERS. WITHIN THIS ENVIRONMENT, SOME THUNDERSTORMS HAVE FORMED ALONG EASTWARD TRAVELING VORT-MAX. ACTUAL SHEAR-PROFILES LOOK QUITE GOOD WITH SOUTHERLY TO EASTERLY SURFACE-WINDS AND STRONG SOUTH-SOUTHWESTERLY FLOW ABOVE ... WITH 30 TO 40 KN WINDSHEAR IN THE LOWEST TWO KILOMETERS. THUNDERSTORMS ARE NOT WELL ORGANISED AT THIS TIME ...HOWEVER... STRONG LOW-LEVEL SHEAR PROFILES GIVE REASON TO ALLOW SOME UPDRAFTS TO ROTATE ... AND SHALLOW SHORT-LIVING MESOCYCLONES SHOULD BE POSSIBLE. WITHIN THIS CONVECTION ... SMALL HAIL AND STRONG WINDGUSTS UP TO 50 KN COULD OCCUR ... SEVERE THREAT SHOULD BE TOO ISOLATED TO WARRANT A SLIGHT RISK THOUGH.

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