The SPC is forecasting ...severe thunderstorms expected over parts of the eastern gulf states this afternoon.... Please read the latest public statement about this event.
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SPC AC 032000 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0300 PM CDT SUN MAY 03 2009 VALID 032000Z - 041200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS EASTERN AL AND WESTERN/NORTHERN GA... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL GULF COAST REGION/SOUTHEAST STATES... ...SOUTHEAST STATES... WITH A WARM/MODERATELY UNSTABLE AIRMASS DOWNSTREAM...WELL-ORGANIZED FAST MOVING DERECHO /WITH A LONG LIVED HISTORY OF WIND DAMAGE/ SHOULD CONTINUE TO POSE A WIDESPREAD DAMAGING WIND/ISOLATED TORNADO THREAT AS IT PROGRESSES EAST-NORTHEASTWARD ACROSS THE REMAINDER OF EAST-CENTRAL/SOUTHEAST AL INTO WESTERN/NORTH GA THROUGH EARLY EVENING. SEE LATEST WATCHES/MESOSCALE DISCUSSIONS FOR THE MOST CONTEMPORARY SHORT TERM DETAILS. ASIDE FROM WIDESPREAD DAMAGING WINDS...PRIMARY TORNADO THREAT OVER THE NEXT SEVERAL HOURS SHOULD REMAIN WITH LEADING QUASI-DISCRETE SUPERCELLS AND/OR NEAR THE INTERSECTION OF THE BOW ECHO AND A MODIFYING/NORTHWARD LIFTING SOUTHWEST-NORTHEAST ORIENTED OUTFLOW BOUNDARY FROM CENTRAL AL INTO WEST CENTRAL/NORTHERN GA. BUT...RELATIVELY MODEST 0-1 KM SRH PER BIRMINGHAM WSR-88D VWP/18Z SPECIAL OBSERVED RAOB...AMPLE DRY AIR ALOFT PER 18Z BMX RAOB...AND AN OBSERVED TREND OF A GRADUALLY DRYING BOUNDARY LAYER DOWNSTREAM OF THE BOW SUGGESTS DAMAGING WIND GUSTS WILL REMAIN THE PRIMARY RISK...WITH ONLY AN ISOLATED/BRIEF TORNADO THREAT OVER THE NEXT FEW HOURS. FARTHER WEST ACROSS THE GULF COAST REGION...IN THE WAKE OF THE BOW ECHO/PARENT SHORTWAVE TROUGH ALOFT...PRIMARY HAZARD WILL TREND TOWARD HEAVY RAINFALL...ALTHOUGH AN ISOLATED DAMAGING WIND/HAIL RISK WILL REMAIN WITH THE STRONGEST TSTMS...MAINLY THROUGH AROUND SUNSET. ...NC/VA... ISOLATED SEVERE /MAINLY DAMAGING WIND/ THREAT MAY CONTINUE OVER THE NEXT FEW HOURS ALONG/JUST SOUTH OF SURFACE FRONTAL ZONE ACROSS SOUTHERN VA/NORTHERN NC. ...NORTHERN INTERMOUNTAIN WEST... REFERENCE MESOSCALE DISCUSSION 689 FOR AFTERNOON/EARLY EVENING ISOLATED SEVERE RISK. ..GUYER.. 05/03/2009 .PREV DISCUSSION... /ISSUED 1129 AM CDT SUN MAY 03 2009/ ..GULF STATES... MATURE AND INTENSE MCV AND ASSOCIATED DERECHO IS MOVING ACROSS MS AT ROUGHLY 60KT AND WILL SOON MOVE INTO AL BEFORE APPROACHING THE GA BORDER BY MID-LATE AFTERNOON. THERE WILL BE A HIGH LIKELIHOOD OF DAMAGING WINDS ACCOMPANYING THE BOWING LINE OF CONVECTION INTO AL OVER THE NEXT FEW HOURS...ESPECIALLY ALONG OLD OUTFLOW BOUNDARY DRAPED IMMEDIATELY AHEAD OF APEX. DOWNSTREAM...AIR MASS EAST TO GA/SC SHOULD BECOME INCREASINGLY UNSTABLE GIVEN DIURNAL HEATING AND EXPECT THIS INSTABILITY TO CONTINUE TO FUEL INTENSE STORM UPDRAFTS ALONG THE LEADING EDGE OF THE ADVANCING COLD POOL AND ALONG THE SOUTHERN TRAILING EDGE OF THIS COMPLEX WHERE LOW LEVEL MOISTURE FLUX WILL BE MAXIMIZED AND LARGE SCALE UPPER LEVEL DYNAMICS WILL CONTINUE TO SUPPORT ASCENT AND STRONG SHEAR. 00Z WRF-NMM SIMULATED REFLECTIVITY FORECAST WAS ABOUT 3H TOO SLOW WITH MCS EVOLUTION ACROSS THE SOUTH. WHEN MODEL FORECAST IS ADJUSTED TO CURRENT TIME AND COMPARED WITH LATEST MOSAIC RADAR ACROSS MS/AL...THE SIMILARITIES ARE QUITE REMARKABLE. USING THAT GUIDANCE...IT APPEARS SIGNIFICANT WIND POTENTIAL WILL CONTINUE EAST ACROSS GA THROUGH LATE AFTERNOON BEFORE SYSTEM BEGINS TO OUTRUN LARGE SCALE SUPPORT. EVEN SO...MESOSCALE VORT WILL LIKELY BE MAINTAINED WITHIN THIS COMPLEX...POSSIBLY ENHANCING CONVECTIVE POTENTIAL EAST INTO SC. TRAILING PORTIONS OF MCS WILL EXTEND WSWWD...JUST NORTH OF IMMEDIATE GULF COAST...FROM SRN MS INTO SERN TX. ONGOING E-W BAND OF STRONG STORMS MAY BEGIN TO SAG SWD LATER IN THE DAY AS COLD POOL NUDGES BOUNDARY TOWARD THE COAST. LARGE HAIL SHOULD BE THE PRIMARY SEVERE THREAT WITH THIS ACTIVITY...THOUGH STRONG WINDS MAY ALSO ACCOMPANY A FEW STORMS. CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z