DAY 2 CONVECTIVE OUTLOOK
VALID 06Z MON 06/01 - 06Z TUE 07/01 2003
ISSUED: 05/01 11:17Z
FORECASTER: GROENEMEIJER

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN PARTS OF THE WESTERN AND CENTRAL MEDITERRANEAN

GENERAL THUNDERSTORMS ARE FORECAST ACROSS NORTHWESTERN IBERIA AND THE WESTERN AND CENTRAL MEDITERRANEAN

SYNOPSIS

A STRONG ZONAL JET STREAM IS LOCATED OVER THE MEDITERRANEAN. AN INTENSE JET STREAK WILL TRACK RAPIDLY EASTWARD OVER THE MEDITERRANEAN REGION. THE AIR-MASS IS STABLE OVER MUCH OF CONTINENTAL EUROPE. SOME MARGINAL INSTABILITY WILL BUILD OVER THE MEDITERRENEAN. LEFT EXIT REGION OF JET STREAK WILL BE PRESENT NEAR SOUTHEASTERN SPAIN AT THE BEGINNING OF THE FORECAST PERIOD.

DISCUSSION

...CENTRAL ITALY AND THE ADRIATIC...
A DEEPENING SURFACE CYCLONE IS PRESENT OVER THE WATERS EAST OF CATALONIA WITH A WARM FRONT EXTENDING SOUTHEAST WARD TO SOUTHERN SARDINIA. THERE ARE THREE AREAS WHERE SEVERE CONVECTION MIGHT DEVELOP....ALONG THE WARM FRONT...ALONG THE COLD FRONT...AND NEAR A DEVELOPING POST-COLD FRONTAL TROUGH. ALONG THE WARM WARM SEVERE THREAT WILL INITIALLY BE SMALL. INSTABILITY ALONG THE WARM FRONT WILL BE MARGINAL...A FEW HUNDREDS OF CAPE AT MOST. HOWEVER...SHEAR PROFILES WILL BE INCREASINGLY FAVOURABLE FOR ROTATING UPDRAFTS AFTER 15Z WHEN WARM FRONT MOVES NORTHWARD OVER ITALY AND THE ADRIATIC. DIRECTLY ALONG WARM FRONT A FEW ROTATING UPDRAFTS/EMBEDDED SUPERCELLS ARE EXPECTED TO FORM WITH A CHANCE OF MARGINALLY SEVERE HAIL AND SEVERE GUSTS. THERE IS A SMALL CHANCE THAT A TORNADO OR TWO WILL FORM.

...SOUTHERN ITALY AND ADJACENT WATERS...
COLD FRONT EXTENDS SOUTHWARD OVER THE WESTERN BALEARES AT THE BEWGINNING OF THE PERIOD. LINEAR FORCING ALONG THE COLD FRONT WILL LIKELY CAUSE THE DEVELOPMENT OF A FAST MOVING SQUALL-LINE. MAIN THREAT WITH THIS ACTIVITY WILL BE SEVERE GUSTS THOUGH SOME MARGINALLY SEVERE HAIL IS ALSO POSSIBLE. DEVELOPMENT OF ROTATING UPDRAFTS AND TORNADOES IS QUITE UNLIKELY INITIALLY. SEVERE THREAT WILL INCREASE SOMEWHAT AFTER 18Z OVER EXTREME SOUTHERN ITALY AND ADJACENT WATERS AS JET STREAK OVER NORTHERN AFRICA WILL REACH FRONTAL ZONE. SURFACE WINDS AHEAD OF THE FRONT WILL BACK AND INSTABILITY WILL INCREASE SLIGHTLY. A FEW SUPERCELLS ARE EXPECTED TO FORM THAT MAY HAVE SOME LARGE HAIL, DAMAGING WINDS AND ALSO A CHANCE OF TORNADOES.

...WESTERN MEDITERRANEAN...
BEHIND THE COLD FRONT AN INTENSE SURFACE TROUGH WILL FORM. DEEP CONVECTION WILL FORM NEAR THE TROUGH AS THE ATMOSPHERE IS MARGINALLY UNSTABLE. SUSTAINED WINDS OF NEAR 50 KTS WILL LIKELY DEVELOP WEST AND SOUTHWEST OF THE SURFACE LOW AFFECTING THE BALEARES AND NORTHERN AFRICA. GUSTS OF UP TO 70 KTS /135 KMH/ ARE POSSIBLE WITH THIS ACTIVITY.

#