MESOSCALE DISCUSSION 0685
   NWS STORM PREDICTION CENTER NORMAN OK
   0906 PM CDT SUN MAY 22 2016

   AREAS AFFECTED...CENTRAL AND EASTERN ND/NORTH-CENTRAL AND NORTHEAST
   SD

   CONCERNING...SEVERE THUNDERSTORM WATCH 192...

   VALID 230206Z - 230400Z

   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 192
   CONTINUES.

   SUMMARY...SEVERE WEATHER THREAT REMAINS LIKELY ACROSS THE SOUTHERN
   AND EASTERN PORTIONS OF WW 192...WITH LOCAL WFO EXTENSION IN AREA
   INTO EASTERN ND POSSIBLE.  MEANWHILE...STORMS WILL CONTINUE TO
   DEVELOP ALONG THE EASTWARD-MOVING COLD FRONT WITH SOME INCREASE IN
   STORM COVERAGE AS THIS FRONT SPREADS INTO CENTRAL ND AND
   NORTH-CENTRAL SD.  HAIL AND DAMAGING WINDS REMAIN THE PRIMARY
   THREATS.

   DISCUSSION...TRENDS IN MOSAIC RADAR IMAGERY AND LIGHTNING DATA SINCE
   THE ISSUANCE OF WW 192 HAVE INDICATED THE GREATEST TSTM COVERAGE IN
   VICINITY OF A PRE-FRONTAL CONVERGENCE ZONE EXTENDING TO THE
   NORTHEAST FROM NEAR PHILIP SD THROUGH NORTH-CENTRAL SD TO THE
   NORTHEAST CORNER OF ND.  THE PRESENCE OF MODERATE INSTABILITY AND
   EFFECTIVE BULK SHEAR ORIENTED NEARLY PARALLEL TO THE SURFACE
   BOUNDARY HAS RESULTED IN RATHER MESSY STORM MODES AS CLUSTERS HAVE
   EVOLVED THIS EVENING ACROSS THE EASTERN PART OF WW 192 IN ND. 
   HOWEVER...STORM ORGANIZATION HAS BEEN SUPERCELLULAR AT TIMES...GIVEN
   EFFECTIVE BULK SHEAR OF 40-50 KT.  IN ADDITION TO A POTENTIAL THREAT
   FOR DAMAGING WIND GUSTS WITH THE STRONGEST STORMS...STEEP MIDLEVEL
   LAPSE RATES /AROUND 7.5 C/KM PER 00Z BIS SOUNDING/ AND THE AVAILABLE
   INSTABILITY AND SHEAR SUGGEST HAIL OF AT LEAST 1 INCH IN DIAMETER
   WILL REMAIN A THREAT.  

   MEANWHILE...STORMS HAVE BEEN STRUGGLING TO BE SUSTAINED ALONG AND
   JUST AHEAD OF A COLD FRONT AS IT ADVANCES EASTWARD FROM WESTERN INTO
   CENTRAL ND AND TOWARD NORTH-CENTRAL SD.  HOWEVER...RECENT RADAR
   IMAGERY SUGGESTS STORMS FROM OLIVER TO MCHENRY COUNTIES ND MAY BE
   ATTAINING SOME ORGANIZATION AS THEY ENCOUNTER STRONGER INSTABILITY
   AND EFFECTIVE BULK SHEAR OF 50 KT ACROSS CENTRAL ND.  HAIL AND
   DAMAGING WINDS WILL BE THE PRIMARY THREATS WITH THIS ACTIVITY AS
   WELL.  SIMILARLY...NEW STORMS HAVE FORMED IN NORTH-CENTRAL SD /DEWEY
   TO EASTERN CORSON AND WESTERN CAMPBELL COUNTIES/ AS FORCING FOR
   ASCENT WITH THE APPROACHING SHORTWAVE TROUGH AND COLD FRONT MOVE
   INTO THIS REGION.

   ..PETERS.. 05/23/2016


   ATTN...WFO...FGF...FSD...ABR...BIS...UNR...

   LAT...LON   44680106 45580187 46730163 47820196 48960191 49049792
               48849745 47919742 46719735 45849775 44649776 44289880
               43949913 44089963 44839972 44680106