MESOSCALE DISCUSSION 1825
   NWS STORM PREDICTION CENTER NORMAN OK
   0610 PM CDT MON AUG 01 2011
   
   AREAS AFFECTED...PORTIONS DAKOTAS
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 713...
   
   VALID 012310Z - 020115Z
   
   CORRECTED FOR UPDATED GUST
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 713
   CONTINUES.
   
   EXISTING ACTIVITY OVER PORTIONS WRN SD MAY EXPAND UPSCALE AFTER
   ENCOUNTERING MORE FAVORABLE MOISTURE/INSTABILITY AND EVOLVE INTO
   MCS.  PORTIONS CENTRAL/ERN DAKOTAS WILL BE MONITORED FOR ADDITIONAL
   WW ISSUANCE.
   
   SFC MESOANALYSIS SHOWS LOW INVOF ND/SD BORDER...SPECIFICALLY
   CORRESPONDING TO CONVERGENCE ZONE EVIDENT IN LOW-LEVEL REFLECTIVITY
   ANIMATIONS ALONG MCPHERSON/MCINTOSH COUNTY LINE.  WARM FRONT IS
   ANALYZED OVER SARGENT COUNTY ND THEN SEWD OVER SWRN MN.  OCCLUDED
   FRONT IS ANALYZED NWWD ACROSS N-CENTRAL SD TO SERN SK... COLD FRONT
   EXTENDS SWD ACROSS PORTIONS STANLEY/PENNINGTON COUNTIES..BEING
   OVERTAKEN BY OUTFLOW ACROSS BADLANDS AND BLACK HILLS REGIONS. 
   COMBINED FRONT/OUTFLOW SHOULD CONTINUE TO MOVE SEWD ACROSS DAKOTAS
   THROUGH REMAINDER EVENING WHILE LOW MOVES EWD ALONG FRONT TO ERN ND.
   
   OUTFLOW-PRODUCING TSTM CLUSTER IS MOVING EWD ABOUT 25-30 KT ACROSS
   ZIEBACH COUNTY ATTM...HAVING PRODUCED SVR GUST OF 69 KT AT D07 AT
   2226Z.  ACTIVITY MAY CATCH UP TO COLD FRONT AND ENTER MORE ROBUST
   MOISTURE JUST E OF MO RIVER.  OTHER/ISOLATED TSTMS HAVE BEEN
   DEVELOPING IN POST COLD-FRONTAL REGIME OVER WRN SD...WHERE AIR MASS
   REMAINS WEAKLY CAPPED AND FAVORABLY UNSTABLE DESPITE PRESENCE OF
   VEERED SFC WINDS AND CAA...AS WELL AS ALONG CONFLUENCE LINE E OF
   OCCLUDED FRONT OVER NERN ND.  PLUME OF ENHANCED SFC MOISTURE...WITH
   DEW POINTS MID 70S TO LOW 80S F...WAS EVIDENT NEAR LOW AND WARM
   FRONT.  MEANWHILE VERTICAL SHEAR WILL REMAIN STRONGEST ALONG/N OF
   WARM FRONT WHERE SFC WINDS ARE WEAK BUT RELATIVELY BACKED.  AS
   LOW-LEVEL WINDS JUST ABOVE SFC INCREASE WITH ONSET OF BOUNDARY-LAYER
   DECOUPLING...SUPPORT FOR TSTMS AND SVR MAY INCREASE OVER ERN
   DAKOTAS.  CONVECTIVE/BOUNDARY/INSTABILITY TRENDS WILL BE MONITORED
   ACCORDINGLY FOR POSSIBILITY OF ADDITIONAL WW.
   
   ..EDWARDS.. 08/01/2011
   
   
   ATTN...WFO...FGF...ABR...BIS...UNR...
   
   LAT...LON   44389974 44140270 44510388 45700335 47740123 48979824
               48799719 47509729 45279848 44509946 44389974