Strong to severe thunderstorms may produce heavy to excessive rainfall over portions of the Central/Southern Plains and Mississippi Valley today. There is a Slight Risk (Level 2 of 4) for Excessive Rainfall and a Slight Risk (Level 2 of 5) for severe thunderstorms today. Elevated fire weather conditions are possible over parts of western Florida today. Read More >
ZCZC SPCSWOD48 ALL ACUS48 KWNS 240850 SPC AC 240850 DAY 4-8 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0350 AM CDT SUN APR 24 2011 VALID 271200Z - 021200Z ...DISCUSSION... WIDESPREAD CONVECTIVE/SEVERE WEATHER EVENT -- ONGOING FROM THE DAY 3 /TUE. 4-26/ PERIOD -- IS LIKELY TO CONTINUE SPREADING EWD ACROSS THE OH/TN VALLEYS AND GULF COAST STATES DAY 4 /WED. 4-27/...AS MEDIUM-RANGE MODELS BOTH FORECAST EWD PROGRESSION OF THE LARGE CENTRAL U.S. TROUGH. AS THE COLD FRONT SHIFTS EWD TOWARD THE APPALACHIANS THROUGH THE AFTERNOON AND EVENING...PRE-FRONTAL WARM SECTOR FEATURING MODERATE INSTABILITY AND STRONG DEEP-LAYER SHEAR WILL SUPPORT CONTINUATION/REDEVELOPMENT OF SEVERE STORMS INTO THE AFTERNOON AND EVENING. POTENTIAL FOR SUBSTANTIAL SEVERE WEATHER -- INCLUDING HAIL/WIND AND ISOLATED TORNADOES -- SUPPORTS CONTINUATION OF A LARGE SEVERE WEATHER THREAT AREA FOR DAY 4. MODEL TIMING WITH RESPECT TO THE SURFACE FRONT AND ASSOCIATED UPPER TROUGH BEGINS TO DIFFER MORE SUBSTANTIALLY DAY 5 /THU. 4-28/...THUS CASTING SOME UNCERTAINTY WITH RESPECT TO LOCATION AND DEGREE OF THREAT E OF THE APPALACHIANS DAY 5. THEREFORE...WHILE POTENTIALLY SEVERE CONVECTION WILL LIKELY SPREAD ACROSS THE ATLANTIC COAST STATES SOMEWHERE BETWEEN LATE IN THE DAY 4 PERIOD AND THE AFTERNOON AND EVENING OF DAY 5...WILL NOT HIGHLIGHT A SPECIFIC THREAT AREA THIS FORECAST. WITH THE FRONT EXPECTED TO HAVE SWEPT OFFSHORE BY THE START OF DAY 6 /FRI. 4-29/...FOCUS SHIFTS WWD AS THE NEXT SYSTEM SHIFTS ACROSS/OUT OF THE ROCKIES. MODELS ARE IN MORE SUBSTANTIAL DISAGREEMENT WITH THE EVOLUTION AND PROGRESSION OF THIS FEATURE...AND THUS WILL NOT HIGHLIGHT ANY LONGER-RANGE THREAT AREAS THIS FORECAST. ..GOSS.. 04/24/2011 CLICK TO GET WUUS48 PTSD48 PRODUCT