MESOSCALE DISCUSSION 1307
   NWS STORM PREDICTION CENTER NORMAN OK
   0833 PM CDT SUN JUN 19 2011
   
   AREAS AFFECTED...NEB
   
   CONCERNING...TORNADO WATCH 513...515...
   
   VALID 200133Z - 200300Z
   
   CORRECTED WATCH TYPE IN CONCERNING LINE
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 513...515...CONTINUES.
   
   INTENSE CONVECTIVE DEVELOPMENT ONGOING ACROSS NORTHEAST COLORADO AND
   SOUTHWESTERN NEBRASKA APPEARS TO BE IN THE PROCESS OF GRADUALLY
   CONSOLIDATING UNDER THE INFLUENCE OF BROADER SCALE ASCENT ASSOCIATED
   WITH LOWER/MID TROPOSPHERIC WARM ADVECTION.  DIFLUENT AND DIVERGENT
   UPPER FLOW DOWNSTREAM OF THE VIGOROUS SHORT WAVE IMPULSE DIGGING
   ACROSS THE FOUR CORNERS REGION IS SUPPORTING THIS ACTIVITY...WHICH
   SHOULD CONTINUE TO ORGANIZE INTO A SEVERE MESOSCALE CONVECTIVE
   SYSTEM THROUGH THE 03-05Z TIME.  MID-LEVEL LAPSE RATES ARE FAIRLY
   STEEP ACROSS MUCH OF NEBRASKA... CONTRIBUTING TO MODESTLY LARGE CAPE
   FOR MOIST PARCELS WITHIN THE INFLOW LAYER.  MID-LEVEL FLOW HAS
   BACKED TO A SUBSTANTIAL SOUTHERLY COMPONENT...AND SOME UNCERTAINTY
   EXISTS CONCERNING HOW FAST THE SYSTEM WILL DEVELOP EASTWARD. 
   HOWEVER...THERMODYNAMIC PROFILES DO APPEAR FAVORABLE FOR THE
   DEVELOPMENT OF A SIGNIFICANT SURFACE COLD POOL.  ONCE FORMED...30 KT
   EASTERLY SYSTEM-RELATIVE FLOW IN THE NEAR SURFACE LAYER COULD
   SUPPORT AN EASTWARD ACCELERATION ACROSS CENTRAL/SOUTHERN
   NEBRASKA...ACCOMPANIED BY AN INCREASING RISK FOR POTENTIALLY
   DAMAGING WIND GUSTS.
   
   ..KERR.. 06/20/2011
   
   
   ATTN...WFO...OAX...GID...LBF...GLD...BOU...CYS...
   
   LAT...LON   40800299 41480182 41910078 42189916 42129824 41859746
               41159736 40349788 40099865 40110050 40090222 40800299