MESOSCALE DISCUSSION 1878
   NWS STORM PREDICTION CENTER NORMAN OK
   0713 AM CDT FRI JUL 18 2003
   
   AREAS AFFECTED...NRN/CNTRL ND
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL 
   
   VALID 181213Z - 181415Z
   
   WW IS NOT ANTICIPATED.
   
   FAIRLY VIGOROUS SHORT WAVE TROUGH CONTINUES TO PROGRESS EASTWARD
   ACROSS THE CENTRAL CANADIAN PROVINCES. STRONGER MID/UPPER FORCING
   FOR UPWARD VERTICAL MOTION ASSOCIATED WITH THIS FEATURE...WHICH
   SUPPORTED CLUSTER OF INTENSE THUNDERSTORMS OVER SOUTHEAST
   SASKATCHEWAN EARLIER THIS MORNING...IS RAPIDLY SHIFTING INTO
   SOUTHERN MANITOBA.  HOWEVER...ZONE OF ENHANCED LOW-LEVEL WARM
   ADVECTION EAST OF LOW/MID-LEVEL TROUGH IN ITS WAKE HAS SUPPORTED NEW
   INTENSE CONVECTIVE DEVELOPMENT PAST COUPLE OF HOURS ON SOUTHWESTERN
   FLANK OF CONVECTIVE CLUSTER...NORTHEAST OF WILLISTON.  THIS ACTIVITY
   WILL LIKELY DEVELOP EAST SOUTHEASTWARD WITH STRONGER LOW-LEVEL
   FORCING THROUGH THE MID MORNING HOURS...INTO AREAS NORTH/NORTHEAST
   OF BISMARCK.
   
   INFLOW FROM NARROW TONGUE OF MOISTURE AHEAD OF LOW-LEVEL TROUGH IS
   SUPPORTING CONVECTIVE DEVELOPMENT...WHICH MODEL FORECAST SOUNDINGS
   SUGGEST IS BASED IN THE 850 TO 700 MB LAYER...WITH CAPE POSSIBLY IN
   EXCESS OF 1000 J/KG.  WITH MODERATE NORTHWESTERLY FLOW ON SOUTHERN
   FRINGE OF STRONGER WESTERLIES ENHANCING SHEAR PROFILES...AND LOW
   RELATIVE HUMIDITIES IN THE SUB CLOUD LAYER...POTENTIAL STILL EXISTS
   FOR HAIL AND STRONG WIND GUSTS..PARTICULARLY AS LOW-LEVELS BEGIN TO
   WARM WITH DAYTIME HEATING.  THREAT...HOWEVER IS EXPECTED TO REMAIN
   CONFINED TO AN ISOLATED STRONGER CELL OR TWO.
   
   ..KERR.. 07/18/2003
   
   
   ATTN...WFO...BIS...
   
   48660223 48500125 48000019 47729989 47230109 47510184
   47870227 48130268