DAY 2 CONVECTIVE OUTLOOK
VALID 06Z FRI 24/01 - 06Z SAT 25/01 2003
ISSUED: 23/01 14:26Z
FORECASTER: GROENEMEIJER

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS A SMALL PART OF THE CENTRAL MEDITERRANEAN INCLUDING EASTERN SARDINIA AND EXTREME WESTERN SICILY.

GENERAL THUNDERSTORMS ARE FORECAST ACROSS MUCH OF THE SOUTH-CENTRAL MEDITERRANEAN REGION

SYNOPSIS

A SOUTHWEST-NORTHEAST ORIENTED RIDGE IS PRESENT FROM WEST OF IBEARIA TO NEAR THE BRITISCH ISLES AT THE BEGINNING OF THE FORECAST PERIOD. OVER THE ALPINE REGION AN UPPER LOW IS MOVING SOUTHWARD. A DEEPENING SURFACE CYCLONE IS MOVING SLOWLY SOUTHWARD OVER THE THYRRENEAN SEA. A DEEP MESOSCALE BAROCLINIC LOW IS RAPIDLY MOVING EATWARD OVER THE ATLANTIC. IT IS FORECAST TO AFFECT THE BRITISH ISLES AFTER THIS PERIOD.

DISCUSSION

...THYRRENEAN SEA AREA...
SURFACE CYCLONE OVER THE THYRREANEAN SEA IS EXPECTED TO MOVE GRADUALLY SOUTHWARD WHILE DEEPENING. STRONG MESOSCALE WIND FIELD WILL BUILD ON THE WESTERN AND SOUTHWESTERN FLANKS OF THIS SYSTEM. NEAR AND WEST OF THE SYSTEM INSTABILITY WILL LIKELY BECOME QUITE SUBSTANTIAL, WITH SURFACE-BASED LIFTED INDICES NEAR -4 FORECAST BY MM5 MODEL. WHERE AREAS OF SLIGTLY HIGHER PV ARE ADVECTED AROUND THE SYSTEM, CONVECTION WILL ORGANIZE INTO LINEAR STRUCTURES. SOME SEVERE WIND GUSTS ARE THE MAIN THREAT. HOWEVER A FEW LOCALIZED ROTATING UPDRAFTS/MINI-SUPERCELLS CAN NOT BE RULED OUT SOME DISTANCE AWAY FROM THE UPPER LOW CENTRE, WHERE MODERATE DEEP-LAYER WIND SHEAR IS PRESENT. IF THESE OCCUR, STRONG BOUNDARY-LAYER WIND SHEAR AND LOW LCL-HEIGHTS INDICATE THAT TORNADOES ARE POSSIBLE. SOME HAIL NEAR SEVERE LIMITS IS ALSO POSSIBLE.

#