MESOSCALE DISCUSSION 1159
   NWS STORM PREDICTION CENTER NORMAN OK
   0123 PM CDT TUE JUN 16 2009
   
   AREAS AFFECTED...NW-N CENTRAL SD AND SW-S CENTRAL ND
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 161823Z - 162000Z
   
   ISOLATED TORNADOES ARE POSSIBLE OVER NW-N CENTRAL SD AND SW-S
   CENTRAL ND DURING THE AFTERNOON. THE AREA WILL BE MONITORED FOR A
   WW.
   
   AT 18Z...A SURFACE LOW WAS LOCATED JUST TO THE NW OF MBG NEAR THE
   SD/ND BORDER. THIS SURFACE LOW WAS POSITIONED IMMEDIATELY BENEATH A
   RELATIVELY COLD /-14 TO -15 DEG C PER 12Z UPPER AIR ANALYSIS/ MID
   LEVEL VORTEX. STEEP LOW LEVEL LAPSE RATES /DUE TO PARTIAL CLEARING/
   ARE NOSING NWD INTO THE REGION BENEATH THE MID LEVEL COLD POOL...AND
   MAY CONTRIBUTE TO ENHANCED LOW LEVEL DESTABILIZATION...CHARACTERIZED
   BY BUOYANCY FOCUSED IN THE LOWEST FEW KM/S /0-3 KM CAPE AOA 100 J
   PER KG/. IN ADDITION...THE LOW LEVEL CYCLONIC FLOW REGIME IS
   RESULTING IN RELATIVELY LARGE AMBIENT CYCLONIC VERTICAL VORTICITY.
   THESE FACTORS MAY CONTRIBUTE TOWARD AN ISOLATED THREAT OF
   NON-SUPERCELL TORNADOES INVOF THE SURFACE LOW.
   
   ..GARNER.. 06/16/2009
   
   
   ATTN...WFO...ABR...BIS...UNR...
   
   LAT...LON   46339964 44759896 44239951 45060146 46390266 47280253
               47520145 46339964