Mesoscale Discussion 0699
   NWS Storm Prediction Center Norman OK
   1117 AM CDT Mon May 20 2019

   Areas affected...southwest into central OK...western north-central
   TX

   Concerning...Severe potential...Tornado Watch likely 

   Valid 201617Z - 201845Z

   Probability of Watch Issuance...95 percent

   SUMMARY...A Particularly Dangerous Situation Tornado Watch will
   likely be needed for portions of central and western OK. 
   Observational trends and short-term model guidance suggest a watch
   being issued during the 1pm-2pm period.

   DISCUSSION...Visible satellite imagery shows a bubbling cumulus
   field over western north-central TX into southwest and south-central
   OK.  Rapid moisture advection is occurring late this morning with
   surface dewpoints rising into the lower 70s over southern OK. 
   Upwards of 4000 J/kg MLCAPE is expected by early to mid afternoon
   across western and central OK with intensifying wind profiles.  

   Short-term model guidance appears to have a reasonable depiction of
   free warm sector initiation occurring over southwest and
   south-central OK during the 2-3pm period.  The observational trend
   in visible satellite imagery showing more pronounced bands of low
   cloud cover ---perhaps indicative of horizontal convective rolls
   and/or low-level confluence zones is supportive evidence for this
   model-based depiction.  The expectation is for storms to develop on
   the northern half of these cloud features with explosive supercell
   development likely thereafter.  Forecast soundings show a very rare
   combination of intense low-level SRH, very moist boundary, and
   extreme buoyancy.  As such, the risk for strong to violent tornadoes
   appears to be increasing later this afternoon into the early
   evening.

   ..Smith.. 05/20/2019

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

   ATTN...WFO...OUN...

   LAT...LON   34199717 33829936 34169988 35509993 35899882 36029706
               35629678 34609685 34199717