Mesoscale Discussion 1721
   NWS Storm Prediction Center Norman OK
   0557 PM CDT Sun Sep 27 2020

   Areas affected...Parts of south central Oklahoma

   Concerning...Severe potential...Watch possible 

   Valid 272257Z - 280100Z

   Probability of Watch Issuance...40 percent

   SUMMARY...A few strong storms are possible across parts of southern
   and eastern Oklahoma into early this evening.  This may include
   potential for a supercell or two, mainly near/east of the Interstate
   35 corridor south-southeast of Oklahoma City.  It is not yet certain
   that a severe weather watch will be needed, but trends are being
   monitored for this possibility.

   DISCUSSION...The surface cold front continues to surge southward
   into the southern Great Plains, generally well south/ahead of the
   stronger mid-level cooling and large-scale forcing for ascent.  The
   shallow leading edge of the cold air may already be undercutting a
   zone of strengthening lift associated with lower/mid tropospheric
   warm advection.  Both sources of lift appear to be contributing to
   increasing precipitation and embedded convective development, which
   seems likely to become mostly focused to the cool side of the
   surface frontal with further southward progression this evening. 

   While the moist pre-frontal boundary layer appears characterized by
   moderately large CAPE, potential for sustained boundary-layer based
   storm development seem confined to a relatively narrow corridor near
   the intersection of the front and the pre-frontal dryline, roughly
   near the Interstate 35 corridor south-southeast of Oklahoma City. 
   Even here, this may be limited in duration, but deep-layer shear
   appears sufficient for an isolated supercell or two.

   ..Kerr/Hart.. 09/27/2020

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

   ATTN...WFO...SHV...TSA...FWD...OUN...

   LAT...LON   35319707 35509613 35579507 34159501 33819725 34969787
               35319707