DAY 1 CONVECTIVE OUTLOOK
VALID 17Z WED 08/01 - 06Z THU 09/01 2003
ISSUED: 08/01 16:52Z
FORECASTER: HAVEN

GENERAL THUNDERSTORMS ARE FORECAST ACROSS PARTS OF IBERIAN PENINSULA, BAY OF BISCAY, LARGE PARTS OF WESTERN MEDITERRANEAN SEA, CENTRAL AND SOUTHERN ITALY, ADRIATIC SEA AND PARTS OF EXTREME WESTERN BALKAN STATES

SYNOPSIS

ON SOUTHERN FLANK OF UPPER LEVEL LOW OVER FRANCE, THE JETSTREAM REMAINS CYCLONICAL CURVED OVER EXTREME NORTHWEST AFRICAN CONTINENT AND WESTERN HALF OF THE MEDITERRANEAN. LEFT EXIT REGION OF JETSTREAK IS SITUATED JUST NORTH OF MAROCCO AND CONTINUES NORTHEAST, EXPECTED OVER EXTREME SOUTHERN ADRIATIC SEA THURSDAY AT 06Z. ASSOCIATED SURFACE LOW CURRENTLY NEAR SARDINIA, ARRIVES OVER CENTRAL ADRIATIC BY THEN. OTHER UPPER SPEED MAXIMUM, SOUTH OF PORTUGAL, CAN BE SEEN CLEARLY IN WATERVAPOUR IMAGERY AND CONTINUES EAST. THIS FEATURE IS ANOTHER FOCUS FOR DYNAMIC LIFT AND THEREBY THUNDERSTORM DEVELOPMENT.

DISCUSSION

...THYRRENIAN SEA, CENTRAL AND SOUTHERN ITALY INTO CENTRAL ADRIATIC SEA...
MARGINAL TO LOW UNSTABLE PROFILES, TOGETHER WITH SUFFICIENT UPPER FORCING HAS LEAD TO THE FORMATION OF SCATTERED THUNDERSTORMS OVER PARTS OF WESTERN MEDITERRANEAN AND IBERIAN PENINSULA. SHEAR OVER S-PART OF THE WESTERN MEDITERRANEAN ISN STRONG ENOUGH TO SUPPORT WINDGUSTS WITH THIS ACTIVITY, WHICH COULD BE ISOLATED SEVERE. NEAR COLDFRONT, CURRENTLY SITUATED NNE-SSW OVER WESTERN THYRRENIAN SEA, THE THREAT FOR SEVERE GUSTS IS ENHANCED. BACKING SURFACE WINDS, JUST EAST OF THIS FRONT, COULD RESULT IN HELICAL INFLOWS/EMBEDDED MESOCYCLONES, WITH PERHAPS A SHORT-LIVED TORNADO OR TWO. HOWEVER, ALL OVER THREAT SEEMS TOO LOW FOR ISSUING A SLIGHT RISK. ACTIVITY WILL SPREAD NORTHEAST DURING THE EVENING AND NIGHT OVER CENTRAL ITALY COASTAL AREAS AND ADRIATIC SEA LATER.

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