MESOSCALE DISCUSSION 1456
   NWS STORM PREDICTION CENTER NORMAN OK
   0955 PM CDT FRI JUL 17 2015

   AREAS AFFECTED...SOUTHEASTERN NORTH DAKOTA...NORTHEASTERN SOUTH
   DAKOTA...AND WESTERN MINNESOTA

   CONCERNING...SEVERE THUNDERSTORM WATCH 430...

   VALID 180255Z - 180400Z

   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 430
   CONTINUES.

   SUMMARY...OVERALL SEVERE THREAT DECREASING ACROSS A LARGE PART OF WW
   430.  PARTS OF THIS WATCH MAY BE CANCELLED.

   DISCUSSION...STORMS OVER NORTHEASTERN SOUTH DAKOTA EARLIER HAVE NOW
   MERGED INTO A LINE STRETCHING FROM NEAR STEVENS COUNTY MINNESOTA TO
   NEAR HAMLIN COUNTY SOUTH DAKOTA.  A DAMAGING WIND AND LARGE HAIL
   THREAT WILL CONTINUE WITH THESE STORMS AS THEY CONTINUE TO
   FORWARD-PROPAGATE INTO AN UNSTABLE AIR MASS WITH AOA 3000 J/KG
   MLCAPE AND 40 KNOTS OF DEEP SHEAR SUFFICIENT FOR CONTINUED
   ORGANIZATION.  THESE STORMS SHOULD MOVE OUT OF SOUTHERN PARTS OF WW
   430 OVER THE NEXT HOUR.

   FARTHER NORTH...CONVECTIVE OVERTURNING HAS LESSENED THE SEVERE
   THREAT OVER THE REMAINDER OF NORTHEASTERN SOUTH DAKOTA.  A FEW
   THUNDERSTORMS ARE ALSO LINGERING ACROSS EAST CENTRAL NORTH
   DAKOTA...BUT THE SEVERE THREAT WITH THESE STORMS IS COMPARATIVELY
   WEAKER COMPARED TO STORMS IN THE SOUTHERN PART OF THE WW DUE TO
   LESSER INSTABILITY.  SOME REDEVELOPMENT IS POSSIBLE LATER GIVEN THE
   APPROACHING MID-LEVEL WAVE OVER FAR SOUTHERN SASKATCHEWAN...BUT
   CONFIDENCE IN THIS SCENARIO IS LOW.  LARGE PARTS OF WW 430 MAY BE
   CANCELLED.

   ..COOK/MEAD.. 07/18/2015


   ATTN...WFO...MPX...FGF...FSD...ABR...BIS...

   LAT...LON   46269793 45229972 44669986 44389956 44299840 44379723
               44699660 45259617 45829588 46159606 46359678 46289758
               46269793