SPC AC 160733

   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0233 AM CDT SUN AUG 16 2015

   VALID 181200Z - 191200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM IA SWWD TO THE SRN HIGH
   PLAINS...

   ...THERE IS A MRGL RISK OF SVR TSTMS FROM THE UPPER MS VALLEY/UPPER
   GREAT LAKES REGION SWWD TO THE CENTRAL AND SRN HIGH PLAINS...

   ...SUMMARY...
   SHOWERS AND THUNDERSTORMS ARE FORECAST ACROSS MUCH OF THE EASTERN
   TWO-THIRDS OF THE COUNTRY TUESDAY...FROM ROUGHLY THE HIGH PLAINS
   EASTWARD.  PRIMARY SEVERE RISK WILL LIKELY RESIDE ACROSS THE CENTRAL
   PART OF THE COUNTRY FROM THE MID-MISSISSIPPI VALLEY SOUTHWEST TO THE
   SOUTHERN HIGH PLAINS

   ...SYNOPSIS...
   A LARGE UPPER TROUGH IS FORECAST TO CONTINUE TO EVOLVE/STRENGTHEN
   ACROSS THE CENTRAL U.S. THIS PERIOD...WITH WEAK RIDGING EXPECTED
   ALONG BOTH THE W AND E COASTS.  AS THE MAIN TROUGH EVOLVES...A
   SURFACE COLD FRONT IS FORECAST TO SHIFT SEWD ACROSS THE PLAINS...AND
   SHOULD EXTEND FROM THE IL VICINITY SWWD ACROSS CENTRAL AND W TX BY
   THE END OF THE PERIOD.  THIS FRONT SHOULD FOCUS AN AXIS OF
   CONVECTION AND ASSOCIATED/ISOLATED SEVERE POTENTIAL THROUGH THE
   PERIOD.

   ...MID MO VALLEY SWWD TO THE SRN HIGH PLAINS...
   FAIRY SIZABLE DIFFERENCES EXISTS AMONGST VARIOUS DETERMINISTIC MODEL
   RUNS ATTM REGARDING EVOLUTION/LOCATION OF THE SURFACE COLD FRONT AND
   ASSOCIATED SURFACE LOW PRESSURE.  THESE DIFFERENCES -- DRIVEN BY
   MORE SUBTLE DIFFERENCES IN MID-LEVEL SHORT-WAVE EVOLUTION WITHIN THE
   LONGER-WAVELENGTH TROUGH -- CAST CONSIDERABLE UNCERTAINTY UPON THE
   CONVECTIVE/SEVERE FORECAST FOR TUE. 8-19.

   ATTM...IT APPEARS THAT STORMS WILL BE WIDESPREAD/ONGOING ACROSS THE
   CENTRAL PLAINS VICINITY AT THE START OF THE PERIOD -- I.E. ACROSS
   MUCH OF THE RISK AREA.  THE GFS WOULD SUGGEST ROBUST STORM
   REDEVELOPMENT ALONG THE COLD FRONT DURING THE AFTERNOON FROM THE IA
   VICINITY SWWD ACROSS KS.  MEANWHILE...THE NAM DEPICTS WHAT APPEARS
   TO BE A CONVECTIVELY-INFLUENCED BOUNDARY MUCH FARTHER E -- I.E. INTO
   NRN IL...AND AS SUCH A MUCH MORE STABILIZED AIRMASS FARTHER W NEARER
   THE MAIN UPPER TROUGH AXIS.

   WHILE THE OVERALL UNCERTAINTY REGARDING LOCATION AND DEGREE OF
   SEVERE RISK IS SURPRISINGLY LARGE ATTM...WILL MAINTAIN A SLIGHT RISK
   FROM IA SWWD TO THE SRN HIGH PLAINS ALONG WITH FAIRLY BROAD MRGL
   RISK AREA INTO IL GIVEN THE LATEST NAM DEPICTION OF THE SURFACE
   PATTERN.  FROM A BROAD PERSPECTIVE...INCREASING MID-LEVEL FLOW FIELD
   ACROSS THE CENTRAL U.S. AROUND THE FAIRLY STRONG UPPER SYSTEM SHOULD
   SUPPORT AREAS OF STRONGER/LOCALLY SEVERE STORMS CAPABLE OF LOCALLY
   DAMAGING WINDS AND HAIL.

   ..GOSS.. 08/16/2015

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   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z