Mesoscale Discussion 0536
   NWS Storm Prediction Center Norman OK
   0642 PM CDT Mon May 04 2020

   Areas affected...eastern Oklahoma...southwestern Missouri...and
   northwestern Arkansas

   Concerning...Tornado Watch 163...

   Valid 042342Z - 050145Z

   The severe weather threat for Tornado Watch 163 continues.

   SUMMARY...Severe/tornado risk remains evident across Tornado Watch
   163, with greatest short-term tornado potential indicated within a
   small corridor near the OK/MO/AR border intersection.

   DISCUSSION...Latest radar loop indicates a broken band of supercell
   storms ongoing near the advancing surface cold front, from
   southwestern Missouri to south-central Oklahoma.  The airmass ahead
   of this band remains moderately unstable, with mid 60s dewpoints
   beneath very steep lapse rates aloft yielding 3000 to 4000 J/kg
   mixed-layer CAPE.  

   While deep-layer shear -- owing to veering/increasing flow with
   height -- is favorable for strongly rotating updrafts given the
   thermodynamic environment, low-level shear remains somewhat weak in
   most areas.  As such, the main risk remains very large hail, and
   locally damaging RFD outflow winds.  

   However, a locally enhanced area for tornado potential over the next
   1-2 hours appears to exist across far northeastern OK, far
   southwestern MO, and into northwestern AR.  Here, a
   northwest-to-southeast outflow boundary is evident, and it appears
   that a supercell now moving southeastward into McDonald County
   Missouri may move along this boundary -- and the associated zone of
   enhanced vorticity.  If this occurs, this storm -- or another cell
   or two just to the southwest -- may pose locally greater tornado
   potential within the narrow corridor in the vicinity of the
   boundary.

   ..Goss.. 05/04/2020

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

   ATTN...WFO...LZK...SGF...SHV...TSA...OUN...

   LAT...LON   34609656 35179674 36089567 37239442 37629349 36929267
               35739289 34489455 34609656