MESOSCALE DISCUSSION 1167
   NWS STORM PREDICTION CENTER NORMAN OK
   0847 PM CDT TUE JUN 16 2009
   
   AREAS AFFECTED...SE SD...NW IA...SW MN
   
   CONCERNING...TORNADO WATCH 435...
   
   VALID 170147Z - 170245Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 435 CONTINUES.
   
   AN ADDITIONAL WW IS NOT ANTICIPATED AT 02Z WATCH EXPIRATION.
   
   A WINDOW OF OPPORTUNITY APPEARS TO EXIST FOR INCREASING STORM
   DEVELOPMENT ABOVE A COLD POOL LEFT BY WEAKENING SUPERCELL NEAR
   YANKTON...AND IN A BROADER SCALE WARM ADVECTION REGIME JUST
   NORTHEAST OF THE MID MISSOURI VALLEY...AROUND SIOUX FALLS AND
   ADJACENT AREAS.  GIVEN LINGERING MODERATE POTENTIAL INSTABILITY...
   AND COOL THERMODYNAMIC PROFILES...LARGE HAIL SHOULD BECOME THE
   PRIMARY SEVERE THREAT.  BUT...IT SEEMS PROBABLE THAT THIS RISK WILL
   DIMINISH BY 03-04Z...DUE TO BOUNDARY LAYER COOLING AND THE ONSET OF 
   INCREASINGLY SUBSIDENT MID-LEVEL FLOW.
   
   ..KERR.. 06/17/2009
   
   
   ATTN...WFO...MPX...FSD...OAX...ABR...
   
   LAT...LON   44449791 44869747 44659623 43619572 42979597 42589643
               42709733 42929802 43739828 44449791