SPC AC 250651

   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0151 AM CDT SUN AUG 25 2013

   VALID 271200Z - 281200Z

   ...NO SVR TSTM AREAS FORECAST...

   ...UPPER MS VALLEY/GREAT LAKES...

   MODEL GUIDANCE IS IN GENERAL AGREEMENT REGARDING THE DOMINANT UPPER
   HIGH THAT HAS SETTLED INTO THE MID SECTION OF THE U.S.  DIFFERENCES
   ARISE AMONG THE NAM/GFS/ECMWF REGARDING THE RIDGE-TOPPING SHORT-WAVE
   TROUGH LATE MONDAY AND ITS ULTIMATE MOVEMENT DOWNSTREAM.  00Z NAM
   ALLOWS FOR A BIT MORE DIGGING ACROSS THE GREAT LAKES THAN EITHER THE
   GFS/ECMWF WHICH RESULTS IN SFC FRONT SAGGING SWD ACROSS MN/WI/LOWER
   MI DURING THE PERIOD.  OTHER SHORT-RANGE GUIDANCE IS MUCH SLOWER
   WITH THIS SWD PUSH DUE TO SHORT-WAVE POSITION.

   LATE DAY2 CONVECTION AND ITS STRENGTH/ORGANIZATION WILL CERTAINLY
   INFLUENCE SWD PUSH OF SYNOPTIC FRONT ACROSS THE GREAT LAKES.  GIVEN
   THE UNCERTAINTY OF THIS BOUNDARY HAVE OPTED TO INTRODUCE 5 PERCENT
   SEVERE PROBS TO ACCOUNT FOR VARIANCES IN FRONTAL POSITION AND
   ATTENDANT CONVECTIVE THREAT.  STRONG HEATING WILL BE INSTRUMENTAL IN
   TSTM DEVELOPMENT AS SFC TEMPERATURES SOAR WELL INTO THE 90S WHERE
   LOW LEVEL FLOW VEERS JUST AHEAD OF THE FRONT.  STORMS THAT DEVELOP
   NEAR THIS BOUNDARY WILL DO SO WITHIN MODEST DEEP LAYER SHEAR AND
   ADEQUATE INSTABILITY ENVIRONMENT FOR AT LEAST ISOLATED DAMAGING
   WINDS AND PERHAPS SOME HAIL.

   ..DARROW.. 08/25/2013

   CLICK TO GET WUUS03 PTSDY3 PRODUCT

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