VALID 16Z TUE 15/10 - 06Z WED 16/10 2002
ISSUED: 15/10 13:52Z
FORECASTER: VAN DER VELDE

GENERAL THUNDERSTORMS ARE FORECAST ACROSS SW NORTH SEA, E BELGIUM, W/C GERMANY, W SIDE OF ALPS, NW SPAIN, FAR E MEDITERRANEAN

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS S ENGLAND

SYNOPSIS

VIGOROUS SFC LOW (988 HPA) WAS SITUATED OVER CORNWALL TUE 12Z WITH STRONG WINDS OVER BRETAGNE AND NORMANDY. OCCLUSION POINT WITH AVN INDICATED UPPER LEVEL DIVERGENCE WITH SOME LIGHTNING ACTIVITY MOVES EAST FROM E BELGIUM OVER W CENTRAL GERMANY. AN OLDER DEPRESSION IS SITUATED OVER THE BALTIC SEA AND THE BALTIC STATES WITH ONLY SHALLOW CONVECTIVE ACTIVITY. CONVECTIVE ACTIVITY ASSOCIATED WITH DISTURBANCES OVER THE ATLANTIC BEHIND THE COLD FRONT WILL REACH NW SPAIN IN WED EARLY MORNING.

DISCUSSION

...S ENGLAND, SW NORTH SEA...
CONVECTIVE ACTIVITY IS ALREADY PRESENT. MOST INSTABILITY, ASSOCIATED WITH THE CORE, WILL REACH THE RELATIVELY WARM NORTH SEA WATERS IN THE EVENING AND CONTINUE GENERATE THUNDERSTORMS. STORMS DEVELOPING UNDER THE HIGH LOW LEVEL WIND SHEAR (40 KTS AT 850 HPA) COULD DEVELOP ROTATING UPDRAFTS AND BRIEF TORNADOES, WARRANTING A SLGT RISK.

...CENTRAL GERMANY...
LIGHTNING ACTIVITY CONTINUES WITHOUT DISCRETE CELLS IN THE PRECIPITATION NEAR THE OCCLUSION. HOWEVER, THERE IS MODERATE SHEAR WITH 60 KTS WINDS AT 700 HPA PRESENT IN THE UCCLE SOUNDING. SHEAR BELOW 700 HPA IS NOT AS HIGH, SUGGESTING LOW POTENTIAL FOR TORNADOGENESIS.

...BALTIC SEA...
SHALLOW CONVECTION WILL BE CAPABLE OF PRODUCING WATERSPOUTS, DUE TO LITTLE WIND SHEAR, HIGH LOW LEVEL MOISTURE AND INSTABILITY PRESENT.

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