MESOSCALE DISCUSSION 1256
   NWS STORM PREDICTION CENTER NORMAN OK
   0604 PM CDT SAT JUN 20 2009
   
   AREAS AFFECTED...SWRN...CNTRL THROUGH NE KS
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 202304Z - 210100Z
   
   A WINDOW OF OPPORTUNITY MAY EXIST FOR ISOLATED TORNADOES THIS
   EVENING IN CORRIDOR FROM SWRN THROUGH CNTRL AND NERN KS. TRENDS ARE
   BEING MONITORED FOR A POSSIBLE WW.
   
   EARLY THIS EVENING A WARM FRONT EXTENDED FROM A SURFACE LOW IN WRN
   KS EWD THROUGH CNTRL KS. THE ATMOSPHERE REMAINS MODERATELY UNSTABLE
   SOUTH OF THIS BOUNDARY WITH 1500 J/KG MLCAPE. SLY LOW LEVEL JET IS
   IN THE PROCESS OF INCREASING ACROSS OK AND KS IN RESPONSE TO
   SHORTWAVE TROUGH EJECTING THROUGH THE CNTRL HIGH PLAINS. LOW LEVEL
   HODOGRAPHS WILL BE MAXIMIZED FROM S CNTRL THROUGH CNTRL KS WHERE
   THIS FEATURE INTERSECTS THE WARM FRONT. RECENT VWP TRENDS INDICATE
   AN INCREASE IN STORM RELATIVE HELICITY IN THIS REGION. STORMS HAVE
   SHOWN AN INCREASE IN INTENSITY LAST HOUR IN VICINITY OF MCV MOVING
   NWD THROUGH S CNTRL KS. CONCERN IS THAT AS THESE STORMS LIFT NWD AND
   INTERACT WITH THE BOUNDARY...A WINDOW OF OPPORTUNITY WILL EXIST FOR
   ISOLATED TORNADOES TO DEVELOP NEXT FEW HOURS BEFORE THE BOUNDARY
   LAYER BEGINS TO STABILIZE TOWARD MID EVENING.
   
   ..DIAL.. 06/20/2009
   
   
   ATTN...WFO...TOP...ICT...DDC...
   
   LAT...LON   38119593 37699804 37559930 38659911 39319582 38519518
               38119593