SPC AC 020707

   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0207 AM CDT TUE SEP 02 2014

   VALID 041200Z - 051200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS WI AND THE U.P. OF MI...

   ...SUMMARY...
   ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS WISCONSIN AND THE
   U.P. OF MICHIGAN THURSDAY.

   ...UPPER GREAT LAKES...

   A CONDITIONAL SEVERE THUNDERSTORM THREAT IS EXPECTED ACROSS THE
   UPPER GREAT LAKES REGION DURING THE DAY3 PERIOD.  LATEST SHORT-RANGE
   MODEL GUIDANCE DEPICTS A STRONG MID-LEVEL SPEED MAX THAT WILL EJECT
   ACROSS THE NRN PLAINS INTO THE ARROWHEAD OF MN BY 05/00Z WITH A
   CORRIDOR OF 70KT+ 500MB FLOW EXPECTED TO EXTEND ACROSS NRN MN INTO
   NWRN ONTARIO.  WHILE CONCENTRATED UVV WILL BE NORTH OF THE
   INTERNATIONAL BORDER...PRONOUNCED SFC FRONT IS EXPECTED TO ADVANCE
   INTO WRN WI BY EARLY AFTERNOON.  ADDITIONALLY...STOUT CAP IS
   EXPECTED TO EXTEND ACROSS THE CNTRL PLAINS INTO WCNTRL WI WHERE A
   PLUME OF VERY WARM 700MB AIR WITH TEMPERATURES AOA 12C ARE EXPECTED
   AT DAYBREAK.  THUNDERSTORMS MAY STRUGGLE TO INITIATE ACROSS THE WARM
   SECTOR BUT MODELS SUGGEST FORCING ALONG COLD FRONT...AND LATE DAY
   MID-LEVEL COOLING...COULD BE SUFFICIENT FOR THUNDERSTORM DEVELOPMENT
   ROOTED IN THE BOUNDARY LAYER.  BOTH THE NAM AND GFS SUGGEST SBCAPE
   SHOULD EXCEED 3000 J/KG WITH SFC DEW POINTS AOA 70F.  DEEP SWLY FLOW
   AND 40-50KT AT 500MB SUGGEST ANY STORMS THAT DEVELOP COULD
   ORGANIZE...MOVING QUICKLY DOWNSTREAM WITHIN A REGIME FAVORABLE FOR
   DAMAGING WINDS AND LARGE HAIL.  SWRN EXTENT OF WARM SECTOR
   CONVECTION SHOULD BE NEAR THE WI/IA BORDER WITH ANY TRAILING STORMS
   LIKELY EVOLVING WITHIN A POST-FRONTAL ENVIRONMENT ACROSS THE CNTRL
   PLAINS.

   ..DARROW.. 09/02/2014

   CLICK TO GET WUUS03 PTSDY3 PRODUCT

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