The SPC is forecasting ...Severe thunderstorms expected over parts of the lower Mississippi and Tennessee Valleys this afternoon and tonight....   Please read the latest public statement about this event.  View What is a Watch? clip.

   SPC AC 281646

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1146 AM CDT MON APR 28 2014

   VALID 281630Z - 291200Z

   ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY
   TONIGHT ACROSS PARTS OF MS...AL..TN...

   ...THERE IS A SLGT RISK OF SVR TSTMS AROSS A LARGE AREA FROM THE
   LOWER/MID MS VALLEY EWD TO THE SRN APPALACHIANS AND CAROLINAS...

   ...SUMMARY...
   A SEVERE WEATHER OUTBREAK IS FORECAST TODAY INTO TONIGHT FROM PARTS
   OF THE LOWER MISSISSIPPI VALLEY INTO THE TENNESSEE VALLEY AND
   CENTRAL GULF COAST STATES. NUMEROUS TORNADOES ARE EXPECTED...SOME OF
   WHICH COULD BE INTENSE. VERY LARGE HAIL AND DAMAGING STRAIGHT LINE
   WINDS ARE ALSO LIKELY.

   ...SYNOPSIS...
   A CLOSED/OCCLUDED LOW OVER ERN NEB WILL WOBBLE EWD ACROSS IA/NRN MO
   AS SERIES OF EMBEDDED SPEED MAXIMA ROTATE AROUND THE SRN AND ERN
   PERIPHERY OF THE LOW.  AT THE SURFACE...THE WARM SECTOR EXTENDS AS
   FAR N/NW AS CENTRAL IL AND SRN IA...THOUGH THE RICHER MOISTURE AND
   GREATER BUOYANCY WILL BE CONFINED TO THE LA/MS/AL AREA TODAY.  THE
   MAIN SEVERE THREATS THIS AFTERNOON WILL BE CONFINED TO TWO CORRIDORS
   - A SUPERCELL/TORNADO RISK FROM MS ACROSS NW AL/SRN MIDDLE TN...AND
   AN ARC OF STORMS WITHIN THE DRY SLOT FROM SRN IA TO CENTRAL IL.

   ...MS/AL/TN THIS AFTERNOON THROUGH TONIGHT...
   MORNING STORMS HAVE BEEN WEAKENING...LEAVING AN OUTFLOW BOUNDARY
   THAT IS BETTER-DEFINED ACROSS SRN MIDDLE TN...AND MORE DIFFUSE WITH
   SWWD EXTENT ACROSS NW MS TO NE LA.  CLEARING OF THE MORNING CLOUD
   DEBRIS IS ALSO ALLOWING STRONGER SURFACE HEATING TO COMMENCE FROM LA
   INTO SW MS...WITH ADDITIONAL CLEARING EXPECTED BY EARLY AFTERNOON
   ACROSS NE MS AND NW AL.  BY EARLY AFTERNOON...WEAKENING OF
   CONVECTIVE INHIBITION SHOULD ALLOW RENEWED STORM DEVELOPMENT ALONG
   OR JUST E OF THE RESIDUAL OUTFLOW BOUNDARY FROM NE LA NEWD ACROSS MS
   AND NW AL TO SRN MIDDLE TN BY EARLY-MID AFTERNOON.  THE STORM
   ENVIRONMENT WILL BE CHARACTERIZED BY MLCAPE NEAR 2000
   J/KG...EFFECTIVE BULK SHEAR OF 50-60 KT...EFFECTIVE SRH OF 200-300
   MS2/S2...AND A MOIST BOUNDARY LAYER.  GIVEN THE SUBTLE FORCING FOR
   ASCENT...A DISCRETE OR CLUSTER SUPERCELL MODE APPEARS LIKELY...WITH
   THE POTENTIAL FOR SEVERAL STRONG AND LONG-TRACK TORNADOES THIS
   AFTERNOON/EVENING FROM CENTRAL MS NEWD TO NW AL.  THIS AREA WILL BE
   MONITORED CAREFULLY FOR A HIGH RISK UPGRADE IN A NARROW CORRIDOR BY
   20Z.

   BY LATE EVENING AND OVERNIGHT...CONVECTION SHOULD EVOLVE INTO A BAND
   OF STORMS WITH EMBEDDED SUPERCELLS AND BOWING SEGMENTS...WITH A
   CONTINUED RISK FOR A FEW TORNADOES...DAMAGING WINDS...AND LARGE HAIL
   WELL INTO THE OVERNIGHT HOURS ACROSS ERN TN...NW GA...AL AND
   CENTRAL/SRN MS. 

   ...ERN MO/WRN IL INTO SRN IA THIS AFTERNOON...
   A BROKEN ARC OF THUNDERSTORMS WILL FORM THIS AFTERNOON ALONG THE
   SURFACE FRONT FROM ERN MO NWD AND NWWD INTO SRN IA...WITH STORMS
   EXPECTED TO SPREAD INTO W CENTRAL IL DURING THE LATE
   AFTERNOON/EVENING.  SOME LOW-TOPPED SUPERCELLS WILL BE POSSIBLE IN
   AN ENVIRONMENT WITH VERY STEEP LAPSE RATES AND MARGINALLY FAVORABLE
   SHEAR...WHICH WILL SUPPORT A RISK FOR LARGE HAIL/DAMAGING WINDS AND
   A COUPLE TORNADOES.

   ...SRN NC/NRN SC THIS AFTERNOON...
   ISOLATED STRONG/SEVERE STORM DEVELOPMENT WILL BE POSSIBLE ALONG THE
   STALLED FRONT THIS AFTERNOON...WHERE LOW-MIDLEVEL VERTICAL SHEAR
   WILL BE SUFFICIENT FOR ORGANIZED CLUSTERS.  MODERATE INSTABILITY
   ALONG THE FRONT AND SEA BREEZE WILL SUPPORT A RISK FOR LARGE
   HAIL/DAMAGING WINDS.

   ..THOMPSON/EDWARDS.. 04/28/2014

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z