MESOSCALE DISCUSSION 1644
   NWS STORM PREDICTION CENTER NORMAN OK
   0634 PM CDT SUN JUL 17 2011
   
   AREAS AFFECTED...SERN ND...NERN SD
   
   CONCERNING...TORNADO WATCH 652...
   
   VALID 172334Z - 180030Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 652 CONTINUES.
   
   ISOLATED LONG-LIVED TORNADIC SUPERCELL...LOCATED OVER LAMOURE COUNTY
   ND...IS PROPAGATING SSEWD AT ROUGHLY 20KT.  THIS STORM IS A BIT
   DEVIANT TO FORECAST STORM MOTION AND BASED ON CURRENT SPEED/MOVEMENT
   SHOULD SPREAD ACROSS DICKEY COUNTY ND INTO BROWN/MARSHALL COUNTY SD
   BEFORE 01Z.  THIS MAY NECESSITATE A NEW TORNADO WATCH OVER NERN SD
   AS ENVIRONMENTAL CONDITIONS ARE QUITE UNSTABLE AND MORE THAN
   ADEQUATELY SHEARED FOR SUPERCELLS/TORNADOES.
   
   ..DARROW.. 07/17/2011
   
   
   ATTN...WFO...FGF...ABR...BIS...
   
   LAT...LON   46749856 46239680 45559627 45059672 45019797 45969931
               46749856