CONVECTIVE FORECAST
VALID 06Z FRI 25/04 - 06Z SAT 26/04 2003
ISSUED: 24/04 16:37Z
FORECASTER: GATZEN

GENERAL THUNDERSTORMS ARE FORECAST ACROSS EASTERN AND SOUTHEASTERN EUROPE, WESTERN EUROPE, PARTS OF THE MEDITERRANEAN

SYNOPSIS

LONG-WAVE RIDGE AMPLIFIES OVER WESTERN CENTRAL EUROPE. EAST OF IT, ARCTIC AIRMASS FLOODS SOUTHWARD INTO EASTERN EUROPEAN TROUGH AND DISPLACES UNSTABLE AIRMASS. WEST OF BUILDING RIDGE ... EASTERN ATLANTIC LONG-WAVE TROUGH EXPANDS EASTWARD. SEVERAL SHORT WAVES EFFECTS WESTERN EUROPE WITHIN THE FORECAST PERIODE.

DISCUSSION

...EASTERN AND SOUTHEASTERN EUROPE...
SOUTH OF ADVANCING COLD FRONT, THUNDERSTORMS WILL FORM DURING THE DAY. THUNDERSTORM ACTIVITY MAY BE ENHANCED ALONG PROGGED CONVERGENCE LINE JUST SOUTH OF THE COLDFRONT. STRONG THUNDERSTORMS ARE NOT LIKELY DUE TO RELATIVELY WEAK INSTABILITY, VERTICAL WIND SHEAR AND WEAK SYNOPTIC-SCALE FORCING. HOWEVER ... STORMS MAY PRODUCE SOME HAIL AND/OR STRONG WIND GUSTS.

...WESTERN EUROPE...
STRENGTHENING CYCLONIC ACTIVITY IS FORECAST OVER EASTERN ATLANTIC. SOUTHWESTERLY FLOW SPREADS OVER WESTERN EUROPE. WAVY FRONTAL BOUNDARY WILL MOVE EASTWARD INTO BENELUX/WESTERN GERMANY ... SOUTHWESTERN FRANCE ... CENTRAL SPAIN ON SATURDAY MORNING. WARM AIR ADVECTION IS FORECAST EAST OF IT. IN THE RANGE OF FRONTAL BOUNDARY ... STRATIFORM RAIN BAND SEEMS TO BE PLAUSIBLE, SOME EMBEDDED THUNDERSTORMS ARE NOT RULED OUT THOUGH. WEST OF THE COLD FRONT ... SHOWERS AND THUNDERSTROMS MAY FORM WITHIN THE COLD AIRMASS. INSTABILITY SHOULD BE RELATIVELY WEAK AND STRONG THUNDERSTORMS ARE NOT FORECAST.

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