VALID 06Z THU 17/10 - 00Z FRI 18/10 2002
ISSUED: 16/10 17:29 Z
FORECASTER: HAVEN

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS S-GERMANY...ALPINE COUNTRIES...NRN ITALY...INTO EASTERN EUROPE

GENERAL THUNDERSTORMS ARE FORECAST ACROSS THE AREA SURROUNDING THE SLIGHT RISK AREA

GENERAL THUNDERSTORMS ARE FORECAST ACROSS WESTERN MEDITERRANEAN SEA

GENERAL THUNDERSTORMS ARE FORECAST ACROSS NORTH SEA AND SURROUNDING LAND AREAS

SYNOPSIS

UPPER FLOW OVER EUROPE CHANGES TO A MORE MERIDIONAL PATTERN AS THERMAL TROUGH ENTERS NORTHWESTERN EUROPE. VORT MAX OVER BALTIC SEA/GERMANY CONTINUES E-NE, WHILE ANOTHER OVER CNTRL FRANCE/SPAIN WILL AFFECT THE ALPINE COUNTRIES, NORTHERN-ITALY AND THE WESTERN MEDITERRANEAN SEA. AT LOWER LEVELS...COLDFRONT FROM BALTIC SEA TO W-ALPES TO ERN SPAIN CONTINUES EAST, WHILE FRONTAL ZONE OVER BALTIC SEA AND BALTIC STATES IS SUBJECT TO STRONG FRONTOGENESIS. MODELS INDICATE PRESSURE FALLS OVER NRN NORTH SEA IN RESPONSE TO APPROACHING THERMAL TROUGH/LEE CYCLOGENESIS.

DISCUSSION

...S-GERMANY...ALPINE COUNTRIES...NRN ITALY...INTO EASTERN EUROPE...
DAY-1 ACTIVITY WILL SHIFT E-NE AND STRENGTHEN DURING THE DAY WITH DAILY CYCLE. STRONG UVM DUE TO APPROACHING VORT MAXIMA WILL OCCUR. INSTABILITY WILL BE LOW WITH CAPE GENERALLY BELOW 250 J/KG OVER THE WHOLE AREA. HOWEVER...DEEP LAYER SHEAR, IN EXCESS OF 60 KTS WILL BE SUPPORTIVE FOR ORGANIZED STRONG/SEVERE STORMS. THESE WILL BE LIKELY ARRANGED INTO LINES WITH DAMAGING WINDS THE MAIN THREAT. OVER NRN ITALY INTO SLOVENIA AND LATER INTO FORMER YUGOSLAVIA... VERY STRONG 0-1 KM SHEAR /30-40 KTS/ WILL CREATE HIGH SRH-VALUES, WHICH WILL BE FAVORABLE FOR TORNADOGENESIS. PERHAPS THIS AREA NEEDS UPGRADING TOMORROW.

...NORTHERN NORTH SEA...
COLD AIR (BELOW -30C) IS ADVECTED OVER WARM SEA WATERS, CREATING AN UNSTABLE ATMOSPHERE WITH A FEW HUNDRED J/KG OF CAPE. SHOWERS AND THUNDERSTORMS ARE EXPECTED, ESPECIALLY NEAR FORMING SFC TROUGH/LOW. WEAK SHEAR PROFILES WILL KEEP SEVERE THREAT FAIRLY LOW.

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