The Good Friday Severe Weather Outbreak of April 10, 2009

Heavy Rainfall in the East Wednesday; Hot Temperatures Continue in Coastal Southern California

Heavy to excessive rainfall may lead to flooding Wednesday over southwest Pennsylvania into northern West Virginia, and western Maryland. Flood Watches have been issued. An extended period of hot weather will continue for parts of coastal southern California including Los Angeles through Thursday. Heat Advisories remain in effect. Read More >

MESOSCALE DISCUSSION 0432 NWS STORM PREDICTION CENTER NORMAN OK 0229 PM CDT FRI APR 10 2009 AREAS AFFECTED...NRN AND CNTRL GA CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 101929Z - 102100Z STORMS ARE EXPECTED TO DEVELOP EWD INTO NRN AND CNTRL GA LATER THIS AFTERNOON AND EVENING. THREAT WILL EXIST FOR SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL AND TORNADOES...A FEW OF WHICH COULD BE STRONG. DAMAGING WIND WILL ALSO BE POSSIBLE WITH SOME OF THE STORMS. A WW WILL LIKELY BE NEEDED BY 20-21Z. PRE-FRONTAL LINE OF MOSTLY DISCRETE SUPERCELLS EXTENDS FROM MIDDLE TN SSWWD THROUGH NRN AL MOVING EAST AT 40-45 KT. A CONVECTIVELY ENHANCED BOUNDARY EXTENDS FROM NRN SC THROUGH NE GA INTO ERN TN. SOUTH OF THESE FEATURES...OTHER PRE-FRONTAL CONVERGENCE BOUNDARIES MANIFESTED BY CLOUD STREETS EXIST OVER MUCH OF THE WARM SECTOR ACROSS CNTRL AL EXTENDING INTO WRN GA. LATEST OBJECTIVE ANALYSIS AND THE 18Z RAOB FROM BIRMINGHAM AND ATLANTA INDICATES MINIMAL TO NO CAP IN WARM SECTOR. THEREFORE...DESPITE A TENDENCY FOR THE STRONGER DEEP FORCING ASSOCIATED WITH THE EWD ADVANCING SHORTWAVE TROUGH TO REMAIN FARTHER NORTH OVER THE TN VALLEY...CONVECTIVE INITIATION MAY OCCUR AS FAR SOUTH AS NORTH CNTRL GA AS THE BOUNDARY LAYER DESTABILIZES EWD WITH TIME. THE COUPLED LOW-MID LEVEL JET STRUCTURE ATTENDING THE SHORTWAVE TROUGH WILL MAINTAIN FAVORABLE WIND PROFILES WITH BULK SHEAR 50+ KT AND 0-1 KM STORM RELATIVE HELICITY FROM 200-300 M2/S2 INTO THE EARLY EVENING. THIS ENVIRONMENT WILL SUPPORT ORGANIZED STORMS INCLUDING SUPERCELLS CAPABLE OF PRODUCING VERY LARGE HAIL AND TORNADOES. ..DIAL.. 04/10/2009 ATTN...WFO...GSP...FFC...BMX... LAT...LON 34948457 34638398 34378351 34148286 33278350 32848474 33498564 34758503 34948457