Mesoscale Discussion 0671
   NWS Storm Prediction Center Norman OK
   0331 PM CDT Sat May 18 2019

   Areas affected...South Central Kansas and Northwest Oklahoma

   Concerning...Severe potential...Watch likely 

   Valid 182031Z - 182230Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Convective development expected in the next 1-2 hours,
   watch likely.

   DISCUSSION...Regional satellite shows a narrow area of developing
   cumulus over portions of southern Kansas and northwest Oklahoma,
   within an axis of modest boundary-layer moisture (low 60s F dew
   points) and clearing on the western periphery of high level clouds
   associated with ongoing convection farther east. Surface
   observations show modest 3-hour pressure falls in this region, with
   a weak mesoscale circulation/meso-low forming, resulting in
   effective bulk shear of 40-50 kt. The combination of diabatic
   heating and cold-air advection aloft (resulting in steepening
   mid-level lapse rates) are serving as the impetus for
   destabilization over the region, with MLCAPE values now approaching
   1000-1500 J/kg, and this trend should continue as the upper-level
   trough axis moves through the region. Farther west, weak convection
   has developed over portions of southeast Colorado, southwest Kansas
   and the Oklahoma Panhandle, in association with a mid-level
   short-wave trough. Convection is expected to initiate soon as this
   feature approaches the region, with large hail the primary risk,
   although a tornado or two is possible. A watch will be issued
   shortly.

   ..Karstens/Hart.. 05/18/2019

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...ICT...OUN...DDC...AMA...

   LAT...LON   35709910 36239980 36790022 37350090 37980061 38209853
               37579776 36599742 36139784 35709910