The SPC is forecasting ...severe thunderstorms expected over parts of the ozarks into lower mississippi valley this afternoon and tonight....   Please read the latest public statement about this event.  View What is a Watch? clip.

   SPC AC 271629

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1129 AM CDT SUN APR 27 2014

   VALID 271630Z - 281200Z

   ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT FOR
   AR AND ADJACENT AREAS OF ERN OK...NE TX...AND SRN MO...

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM E TX AND NRN LA NWD TO THE
   MIDDLE MO AND MS RIVER VALLEYS...

   ...SUMMARY...
   SEVERE THUNDERSTORMS WILL AFFECT ARKANSAS AND ADJACENT AREAS OF
   SOUTHERN MISSOURI...EASTERN OKLAHOMA...AND EXTREME NORTHEAST TEXAS
   THIS AFTERNOON INTO TONIGHT.  THE GREATEST TORNADO RISK WILL BE
   CENTERED ON ARKANSAS...WHERE A FEW STRONG AND LONG-TRACK TORNADOES
   WILL BE POSSIBLE THROUGH TONIGHT.  OTHERWISE...A BAND OF SEVERE
   THUNDERSTORMS WILL MOVE ACROSS MISSOURI AND IOWA THIS AFTERNOON WITH
   DAMAGING WINDS...LARGE HAIL...AND A FEW TORNADOES.  MORE ISOLATED
   SEVERE STORMS WILL BE POSSIBLE THIS AFTERNOON ACROSS CENTRAL
   NEBRASKA.

   ...SIGNIFICANT SEVERE WEATHER EPISODE STILL EXPECTED THIS
   AFTERNOON/TONIGHT CENTERED ON AR...WHERE A FEW STRONG/LONG-TRACK
   TORNADOES WILL BE POSSIBLE...

   ...SYNOPSIS...
   A STRONG MIDLEVEL SHORTWAVE TROUGH IS EVOLVING INTO A CLOSED LOW AS
   THE SYNOPTIC SYSTEM OCCLUDES OVER THE CENTRAL HIGH PLAINS.  THE
   ASSOCIATED SURFACE CYCLONE APPEARS TO HAVE REACHED PEAK
   INTENSITY...AND IT WILL VERY SLOWLY WEAKEN WHILE MOVING EWD NEAR THE
   KS/NE BORDER THROUGH EARLY TONIGHT. A TRAILING COLD FRONT/DRYLINE
   WILL MOVE SLOWLY EWD ACROSS ERN KS/OK AND N TX.  THE PRIMARY SEVERE
   RISKS WILL BE WITH THE MORNING PRE-FRONTAL CONVECTION FROM KS/OK
   INTO MO/IA...AND WITH ADDITIONAL WARM SECTOR SUPERCELL DEVELOPMENT
   FROM SE OK/NE TX INTO AR.

   ...ARKLATEX NEWD ACROSS MUCH OF AR/SRN MO...
   THE RICHEST MOISTURE IN THE WARM SECTOR IS SPREADING INTO SRN AR AND
   NE TX BENEATH STEEP MIDLEVEL LAPSE RATES PER 12Z SOUNDINGS.  STRONG
   SURFACE HEATING EXPECTED ACROSS NRN LA AND SRN AR THROUGH THE
   AFTERNOON...WHERE UPPER 60S BOUNDARY LAYER DEWPOINTS AND AFTERNOON
   TEMPERATURES NEAR 80 F WILL SUPPORT MLCAPE OF 2500-3000 J/KG.  THE
   N/NE EDGE OF THE STRONGER BUOYANCY /SW OF THE ONGOING WAA STORMS
   OVER E AND NE AR THIS MORNING/ WILL COINCIDE WITH STRONG LOW-LEVEL
   SHEAR AND A 40-50 KT LLJ.  IT APPEARS THAT THE EARLY PRE-FRONTAL
   CONVECTION IN NE TX/ERN OK WILL EVENTUALLY EVOLVE INTO WARM SECTOR
   SUPERCELLS THIS AFTERNOON...AS DESTABILIZATION PROCEEDS AND AS
   VERTICAL SHEAR PROFILES IMPROVE WITH PASSAGE OF THE LEAD SHORTWAVE
   TROUGH THIS MORNING.

   A FEW STRONG/LONG-TRACK TORNADOES WILL BE POSSIBLE WITH THESE
   SUPERCELLS...GIVEN EFFECTIVE SRH OF 300-400 M2/S2...MODERATE
   BUOYANCY...AND MOIST LOW LEVELS.  A DISCRETE OR CLUSTER SUPERCELL
   MODE WILL LIKELY CONTINUE FROM THIS AFTERNOON THROUGH TONIGHT ACROSS
   AR...PROLONGING THE TORNADO AND SEVERE THUNDERSTORM RISK.

   ...CENTRAL NEB TO SRN IA/ERN KS/MO THROUGH THIS EVENING...
   THE FORECAST SITUATION HAS BEEN COMPLICATED SUBSTANTIALLY BY AN
   EXPANSIVE BAND OF MORNING CONVECTION ALONG AND AHEAD OF THE PACIFIC
   COLD FRONT/DRYLINE FROM ERN OK NWD ACROSS ERN KS TO SE NEB.  THIS
   CONVECTION HAS PROPAGATED WELL E OF THE SURFACE COLD FRONT/DRYLINE
   AND IS ASSOCIATED WITH ASCENT ABOVE THE SURFACE PRECEDING THE
   INITIAL SPEED MAX ROTATING AROUND THE DEVELOPING MIDLEVEL LOW NEAR
   THE KS/CO BORDER.  THE PRIMARY SEVERE THREAT FROM ERN KS INTO MO/IA
   WILL BE WITH A CONTINUATION OF THIS ONGOING CONVECTION.  SOME
   DESTABILIZATION WILL OCCUR IN ADVANCE OF THIS CONVECTION...THOUGH
   WIDESPREAD CLOUDS WILL HINDER SURFACE HEATING SOME.  ALSO...THE
   CONVECTIVE MODE IS ALREADY MESSY/COMPLEX AND MAY REMAIN SO THROUGH
   THE AFTERNOON GIVEN THE PRONOUNCED BACKING OF MID-UPPER FLOW NOTED
   IN KS/MO VWP/S.  A MIX OF EMBEDDED BOWS AND SUPERCELLS WILL BE
   CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING GUSTS...AS WELL AS A
   FEW TORNADOES.
     
   BOUNDARY LAYER DEWPOINTS REMAIN IN THE 58-60 F RANGE NEAR AND BEHIND
   THIS INITIAL CONVECTION...SUCH THAT ADDITIONAL STORM DEVELOPMENT
   WILL BE POSSIBLE ALONG THE SURFACE BOUNDARY AND WITHIN THE MIDLEVEL
   DRY SLOT THIS AFTERNOON ACROSS CENTRAL NEB AS SOME CLEARING OCCURS
   FROM THE S.  SUPERCELLS WILL BE POSSIBLE IN THIS EXPECTED ARC OF
   CONVECTION...WITH A COUPLE OF TORNADOES...LARGE HAIL...AND A FEW
   DAMAGING GUSTS POSSIBLE THIS AFTERNOON.

   ..THOMPSON/DEAN.. 04/27/2014

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