DAY 2 CONVECTIVE OUTLOOK
VALID 06Z SAT 11/01 - 06Z SUN 12/01 2003
ISSUED: 10/01 14:35Z
FORECASTER: GROENEMEIJER

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS EXTREME SOUTHERN ITALY, WESTERN ALBANIA, MUCH OF GREECE AND EXTREME WESTERN TURKEY

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EXTREME SOUTHERN ITALY, WESTERN ALBANIA, MUCH OF GREECE AND EXTREME

GENERAL THUNDERSTORMS ARE FORECAST ACROSS MUCH OF THE MEDITERRANEAN, THE NORTHERN COAST OF SPAIN AND SOUTHWESTERN FRANCE

SYNOPSIS

A NORTHEAST-SOUTWEST ORIENTED LONG-WAVE TROUGH IS PRESENT OVER CENTRAL EUROPE. A STRONG WESTERLY JET IS BLOWING OVER THE SOUTHERN MEDITERRANEAN AND NORTHERN AFRICA. A VERY INTENSE /130 KT @ 300 HPA/ JET STREAK IS EXPECTED ROUND THE BASE OF THE TROUGH.

DISCUSSION

...SOUTHERN ITALY, WESTERN ALBANIA, GREECE, EXTREME WESTERN TURKEY...
AS JET LIFTS OUT OF ALGERIA/TUNESIA STRONG SURFACE CYCLOGENESIS IS FORECAST NEAR SICILY. AHEAD OF DEVELOPING COLD FRONT, STRONG WARM ADVECTION WILL TAKE PLACE. LOW-LEVEL WIND WILL BE MODERATE AND EXHIBIT SUBSTANTIAL VEERING, RESULTING IN HIGH 0-3 KM STORM-RELATIVE HELICITIES ON THE ORDER OF 300 - 600 M2/S2. WHILE INSTABILITY WILL BE INITIALLY BE MARGINAL, STRONG WARM ADVECTION AHEAD OF COLD FRONT IS EXPECTED TO PRODUCE A BAND OF CONSIDERABLE LATENT INSTABILITY / UP TO 1500 J/KG SBCAPE. MAIN SEVERE THREAT WILL BE ALONG THE COLD FRONT WHERE DEVELOPMENT OF SUPERCELLS SEEMS LIKELY. THERE IS A CHANCE FOR LARGE HAIL AND DAMAGINGS WINDS WITH THESE STORMS. THERE IS ALSO A CHANCE OF TORNADOES, ESPECIALLY NEAR AND JUST SOUTH OF THE WARM FRONT WHERE LOW-LEVEL WINDS ARE MOST BACKED. FURTHER SOUTH...BACKING OF LOW-LEVEL WINDS DUE TO OROGRAPHIC INFLUENCES MAY AID IN TORNADO DEVELOPMENT. THE COLD FRONT WILL AFFECT WESTERN GREECE/ALBANIA IN THE EARLY EVENING HOURS AND MOVE INLAND DURING THE EVENING. SEVERE THREAT WILL BE SOMEWHAT REDUCED INLAND AS INSTABILITY WILL BE LESS DUE TO DRIER AND COLDER AIR PRESENT OVER LAND. THE AEGEAN SEA AND POSSIBLY NORTHEASTERN GREECE AND WESTERN TURKEY WILL BE AFFECTED OVERNIGHT. A POST-FRONTAL TROUGH /BACK-BENT OCCLUSION/ WILL ALSO POSE A MINOR THREAT OF SEVERE THUNDERSTORMS. HERE, INSTABILITY WILL BE LOWER AND SHEAR UNIDIRECTIONAL, BUT STRONG. DEVELOPMENT OF A LINEAR CONVECTIVE SYSTEM IS EXPECTED. MAIN THREAT WITH THIS ACTIVITY ARE SEVERE GUSTS.

...SICILY AND SOUTHERN ITALY...
VERY STRONG RISING MOTIONS ARE EXPECTED ALONG THE WARM FRONT AND NEAR THE CYCLONE CENTER, WHERE VERY HIGH PRECIPITATION RATES ARE EXPECTED. TOTAL AMOUNTS WILL BE NEAR 100 MM OVER SICILY AND SOMEWHAT LESS ELSEWHERE.

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