SPC AC 280457

   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1157 PM CDT TUE AUG 27 2013

   VALID 291200Z - 301200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN ND INTO NWRN WI...

   ...NRN PLAINS TO UPPER GREAT LAKES...

   UPPER RIDGE AXIS IS EXPECTED TO RETROGRADE ACROSS THE HIGH PLAINS
   DURING THE DAY2 PERIOD WITH CENTER OF UPPER ANTICYCLONE FORECAST TO
   BE POSITIONED OVER CO BY 20/12Z.  THIS WWD SHIFT TO UPPER RIDGE
   SHOULD PROVE MORE FAVORABLE FOR RIDGE-TOPPING SHORT-WAVES TO DIG
   INTO THE UPPER MS VALLEY/GREAT LAKES REGION LIKELY INSTIGATING
   THUNDERSTORM CLUSTERS FROM PORTIONS OF ERN ND INTO WI.

   LATEST SHORT-RANGE MODEL GUIDANCE IS FAIRLY CONSISTENT REGARDING THE
   LIKELIHOOD FOR EARLY MORNING CONVECTION WITHIN WARM ADVECTION ZONE
   OVER ND/MN.  THIS ELEVATED TSTM ACTIVITY MAY NOT DISSIPATE DURING
   THE DAY BUT RATHER PROPAGATE EWD AND POSSIBLY INTENSIFY AS LLJ
   SHIFTS INTO MN BY PEAK HEATING.  NAM/GFS BOTH AGREE THAT WEAK SFC
   BOUNDARY WILL ADVANCE TO A POSITION ALONG THE ND/MN BORDER...SWWD
   THROUGH A WEAK SFC LOW INTO THE NEB PANHANDLE BUT A POTENTIALLY MORE
   SIGNIFICANT NW-SE ORIENTED WARM FRONT SHOULD EXTEND ACROSS MN/WI. 
   CONVERGENCE SHOULD BE MAXIMIZED DOWNSTREAM OF SFC LOW AND THIS IS
   THE LIKELY FOCUS FOR POTENTIAL ROBUST ORGANIZED DEVELOPMENT.  NAM
   FORECAST SOUNDINGS NEAR THE WARM FRONT ARE QUITE BUOYANT AND
   STRONGLY SHEARED...SFC-6KM BULK SHEAR ON THE ORDER OF 40KT...WITH
   THE POTENTIAL FOR MUCAPE AOA 2000 J/KG.  WHILE SEVERAL WARM
   ADVECTION CLUSTERS OR AN MCS MAY BE THE DOMINANT STORM MODE THERE IS
   REASON TO BELIEVE A FEW SUPERCELLS COULD EMERGE ACROSS THIS REGION. 
   AS A RESULT HAVE INCREASED SEVERE PROBS WITHIN THE WARM ADVECTION
   ZONE WHERE STRONG HEATING WILL IMPINGE ON BOUNDARY ENHANCING THE
   RISK FOR NEAR-SFC BASED UPDRAFTS THAT COULD ROTATE.  HAIL/WIND ARE
   THE PRIMARY THREATS WITH THIS ACTIVITY.

   ...ELSEWHERE...

   SCT-NUMEROUS SHOWERS/THUNDERSTORMS WILL AGAIN BE NOTED ACROSS AZ
   INTO PORTIONS OF THE GREAT BASIN WITHIN FAVORABLE SELY DEEP LAYER
   FLOW ALONG WRN HEMISPHERE OF ANTICYCLONE.  SCT CONVECTION IS ALSO
   ANTICIPATED ACROSS THE NWRN U.S. AHEAD STRONG SHORT-WAVE TROUGH.  IF
   SUFFICIENT BUOYANCY CAN EVOLVE ACROSS THE NRN ROCKIES THERE MAY BE A
   NEED FOR LOW SEVERE PROBS GIVEN THE STRENGTHENING FLOW ALOFT.

   ..DARROW.. 08/28/2013

   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z