DAY 2 CONVECTIVE OUTLOOK
VALID 06Z SAT 29/03 - 06Z SUN 30/03 2003
ISSUED: 28/03 19:03Z
FORECASTER: DAHL

GENERAL THUNDERSTORMS ARE FORECAST ACROSS THE SW MEDITERRANEAN SEA.

GENERAL THUNDERSTORMS ARE FORECAST ACROSS EASTERN EUROPE.

GENERAL THUNDERSTORMS ARE FORECAST ACROSS THE NORTHERN ATLANTIC.

SYNOPSIS

MAIN UPPER FRONTAL ZONE WILL STRETCH ACROSS THE NORTHERN EUROPEAN PARTS OVER THE FCST PERIOD. WEAKER FRONTAL ZONE IS EVIDENT OVER THE SOUTHERN REGIONS OF THE FORECAST AREA. WEAK UPPER CUT-OFF LOW SLOWLY PUSHING EAST ACROSS POLAND AT THE SOUTHERN FRINGE OF THE NORTHERN UPPER JET. SURFACE PRESSURE FIELD REFLECTS THE ABSENCE OF UPPER FEATURES ACROSS CENTRAL EUROPE ... LEAVING MOST PARTS OF EUROPE IN SYNOPTICALLY QUIESCENT CONDITIONS. RAOBS AND NUMERICAL ANALYSES INDICATE THAT AIRMASS ACROSS MOST OF CENTRAL AND SOUTHERN EUROPE IS CHARACTERIZED BY ESSENTIALLY NEUTRAL LAPSE RATES.

DISCUSSION

...EASTERN EUROPE...
TSTMS SHOULD DEVELOP DURING THE AFTERNOON BENEATH THE UPPER CUT-OFF LOW OVER POLAND ... WHERE PLUME OF WEAKLY UNSTABLE AIRMASS IS WRAPPING AROUND THE ASSOCIATED SURFACE LOW CENTER. THOUGH TSTMS SHOULD GENERALLY BE QUITE ISOLATED AND WEAK ... SMALL HAIL MAY OCCUR WITH THE STRONGER CELLS. GIVEN SLOW STORM MOTION ... AMOUNTS OF PRECIP MAY LOCALLY BE RATHER HIGH.

FARTHER WEST ... AIRMASS WILL LIKELY BECOME SLIGHTLY UNSTABLE DURING THE DAY ACROSS PORTIONS OF EASTERN FRANCE AND WESTERN GERMANY WITHIN WEAK 850 HPA THETA-E PLUME. SUBTLE WAA AT THE EASTERN EDGE OF THIS FEATURE IS PROMOTING WEAK LOW-LEVEL ASCENT ATTM ... AND A FEW POSSIBLY ELEVATED SHOWERS HAVE FORMED. THIS ACTIVITY SHOULD BE MAINTAINED/STRENGTHEN OVER THE NIGHT/EARLY MORNING BUT CONFIDENCE THAT TSTMS FORM IS RATHER LOW. DURING THE DAY ... DEGREE OF LOW-LEVEL UPWARD FORCING APPEARS TO BE TOO LOW TO INITIATE THUNDERSTORMS. HOWEVER ... WEAK OROGRAPHIC FORCING MAY PROVE SUFFICIENT TO SUPPORT FORMATION OF ISOLATED TSTMS DURING THE AFTERNOON. AREAL COVERAGE IS EXPECTED TO BE TOO LOW THOUGH TO WARRANT A GEN THUNDERSTORM AREA BUT CENTRAL EUROPE MAY BE INCLUDED IN A GEN THUNDER AREA WITH TOMORROW'S OUTLOOK.

...SOUTH-CENTRAL AND EASTERN MEDITERRANEAN...
ILL-DEFINED LOBES OF WEAK CVA EXPECTED TO BE PRESENT ACROSS THE MEDITERRANEAN REGIONS AT THE PERIPHERY OF A WEAKENING SOUTHERN STREAM TROUGH. GIVEN UNCERTAINTY ABOUT DEVELOPING INSTABILITY OF THE AIRMASS ACROSS THE MEDITERRANEAN ... WILL NOT OUTLOOK THUNDERSTORMS ACROSS THE MEDITERRANEAN AS WELL ... AND LATER OBSERVATIONS HAVE TO BE AWAITED TO SPECIFY THREAT OF THUNDERSTORM DEVELOPMENT.

...SW MEDITERRANEAN ...
SUBTROPICAL AIRMASS IS EXPECTED TO ADVECT INTO THE SOUTHWESTERN MEDITERRANEAN REGIONS AHEAD OF ANOTHER SRN STREAM TROUGH ... UPPER SUPPORT WILL LIKELY BE FAIRLY WEAK THOUGH ... AND THUNDERSTORMS SHOULD BE RATHER UNLIKELY. BEST POTENTIAL FOR A FEW ELEVATED THUNDERSTORMS APPEARS TO EXIST AT THE NOSE OF THE THETA-E PLUME OVER THE SOUTHWEST MEDITERRANEAN SEA IN REGION OF ENHANCED LOW-LEVEL WAA LATE SUNDAY NIGHT.

#