SPC AC 191728
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1228 PM CDT SUN MAY 19 2013
   
   VALID 201200Z - 211200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS OK...SERN KS...EXTREME
   NWRN AR...AND SWRN MO...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
   SWRN TX TO THE UPPER GREAT LAKES...
   
   ...SOUTHERN PLAINS TO MID MS VALLEY...
   
   SECONDARY MID LEVEL SPEED MAX...ON THE ORDER OF 60KT AT 500 MB...IS
   EXPECTED TO EJECT ACROSS THE SRN ROCKIES INTO NRN OK BY 21/00Z. 
   WHILE LATE DAY1 CONVECTION MAY DISTURB LOW LEVEL WIND FIELDS ACROSS
   PORTIONS OF SERN KS INTO MO...IT APPEARS LARGE SCALE INFLUENCE OF
   APPROACHING SPEED MAX SHOULD SHARPEN SYNOPTIC FRONT ACROSS OK BY
   PEAK HEATING.  THIS WILL BE THE PRIMARY FOCUS FOR RENEWED SEVERE
   THUNDERSTORM DEVELOPMENT ACROSS THE MDT RISK REGION.
   
   THUNDERSTORMS...A FEW SEVERE WITH A THREAT OF HAIL...MAY BE ONGOING
   AT THE BEGINNING OF THE PERIOD ACROSS SERN KS/MO ALONG THE NOSE OF
   VEERED LLJ.  THIS CONVECTION MAY TEMPORARILY DISPLACE THE SYNOPTIC
   FRONT OR PERHAPS EVEN PRODUCE OUTFLOW THAT BECOMES A FOCUS FOR
   AFTERNOON CONVECTIVE DEVELOPMENT.  STRONGEST BOUNDARY LAYER HEATING
   IS EXPECTED ACROSS WEST TX INTO SWRN OK WHERE SFC TEMPERATURES
   SHOULD SOAR INTO THE 90S.  ALONG/NORTH OF THE MAIN MID LEVEL JET
   CORE MID LEVEL TEMPERATURES SHOULD COOL SUCH THAT DEEP CONVECTION
   WILL EASILY DEVELOP ALONG AFOREMENTIONED CONVECTIVE OUTFLOW BOUNDARY
   INTO MO AND SHARPENING COLD FRONT/DRYLINE FARTHER WEST.  IN
   FACT...TSTMS MAY DEVELOP BY 20-21Z ACROSS OK WHERE SBCAPE IS
   EXPECTED TO BE IN EXCESS OF 3000 J/KG.  FORECAST DEEP LAYER
   SHEAR...IN EXCESS OF 50KT THROUGH 6KM...AND THE PROSPECT FOR A VERY
   MOIST WARM SECTOR FAVOR NUMEROUS SUPERCELL STRUCTURES...AT LEAST
   THROUGH MID EVENING OF THE CONVECTIVE CYCLE.  VERY LARGE HAIL AND
   TORNADOES ARE POSSIBLE WITH SUPERCELLS AND WITH TIME ONE OR MORE
   MCS/S SHOULD EVOLVE ALONG NOSE OF STRENGTHENING LLJ OVER OK.  AMPLE
   MID LEVEL FLOW WILL EXTEND ALONG THE DRYLINE INTO THE EDWARDS
   PLATEAU OF TX SUPPORTIVE OF ISOLATED SUPERCELL STRUCTURES CAPABLE OF
   PRODUCING AT LEAST LARGE HAIL AND DAMAGING WINDS.
   
   
   ...UPPER MS VALLEY/GREAT LAKES...
   
   LATEST MODEL GUIDANCE SUGGESTS A MID LEVEL SHORT WAVE TROUGH/SPEED
   MAX WILL ROTATE NEWD ACROSS IA/IL INTO MN/WI DURING THE AFTERNOON
   HOURS.  THIS FEATURE WILL SERVE TO INCREASE UVV ACROSS A FAIRLY
   MOIST/UNSTABLE BOUNDARY LAYER SOUTH OF SHARP WARM FRONT THAT WILL
   EXTEND FROM LOW NEAR THE ND/SD/MN BORDER...EWD INTO NRN WI AT PEAK
   HEATING.  WHILE SHORT WAVE TROUGH WILL INFLUENCE/SUPPORT DEEP
   CONVECTION...STRONG BOUNDARY LAYER HEATING WILL PROVE INSTRUMENTAL
   IN DESTABILIZATION ACROSS MN/WI AND SBCAPE COULD EASILY RISE TO NEAR
   2000 J/KG.  DISCRETE SUPERCELL STRUCTURES MAY EVOLVE WITHIN THIS
   AIRMASS AND WITH RELATIVELY LOW CLOUD BASES ISOLATED TORNADOES...IN
   ADDITION TO LARGE HAIL MAY BE OBSERVED.
   
   ..DARROW.. 05/19/2013
   
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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z