Mesoscale Discussion 1649
   NWS Storm Prediction Center Norman OK
   0418 AM CDT Mon Aug 31 2020

   Areas affected...Parts of eastern Oklahoma and adjacent western
   Arkansas into southeastern Kansas and southwestern Missouri

   Concerning...Severe potential...Watch unlikely 

   Valid 310918Z - 311115Z

   Probability of Watch Issuance...20 percent

   SUMMARY...A period of increasing, intensifying and organizing
   thunderstorm development is possible through daybreak, which may
   pose at least some risk for severe hail and wind.  While it is not
   clear that a severe weather watch will be needed, trends are being
   monitored.

   DISCUSSION...Recent thunderstorm initiation to the west and
   southwest of Tulsa OK appears in response to forcing for ascent
   associated with warm advection and convergence, on the nose of a
   strengthening southwesterly low-level jet (30-40 kt).  Model output
   suggest that this is occurring within a weakness in mid-level
   inhibition associated with warm elevated mixed-layer air (as
   inferred from temperatures around 700 mb), where seasonably high
   moisture content is contributing to most unstable CAPE on the order
   of 2000-3000 J/kg.

   Although mid-level winds are only modest in strength, veering with
   height from lower to mid-levels, beneath a belt of 40-60+ kt
   westerly high-level flow, is contributing to moderate to strong
   deep-layer shear across the region.  

   Given this environment, vigorous convective development is expected
   to persist through daybreak, with an isolated supercell or two
   capable of producing severe hail possible.  And there appears at
   least potential for merging/upscale growing convection to organize
   into one or two small clusters, which could eventually pose a risk 
   for strong surface gusts.  

   While this may be largely confined to east-central Oklahoma and
   adjacent portions of Arkansas through 11-13Z, similar type
   thunderstorm development may gradually spread north-northeastward,
   near the eastern edge of the capping elevated mixed-layer, toward
   the southern Missouri/Kansas state border vicinity.

   ..Kerr/Edwards.. 08/31/2020

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

   ATTN...WFO...LZK...SGF...TSA...ICT...OUN...

   LAT...LON   35989648 36589601 37609536 37599419 36959387 35919405
               34899379 34609491 34849585 35279651 35989648