Mesoscale Discussion 1535
   NWS Storm Prediction Center Norman OK
   0504 PM CDT Thu Aug 20 2020

   Areas affected...Southeast Arizona and far southwest New Mexico

   Concerning...Severe potential...Watch unlikely 

   Valid 202204Z - 202300Z

   Probability of Watch Issuance...5 percent

   SUMMARY...A transient severe risk will continue through the late
   afternoon and early evening hours. Strong winds and hail are
   possible with the strongest storms, but a watch is not expected.

   DISCUSSION...Recent regional radar imagery shows ongoing convection
   from central to southeast AZ and into far southwest NM. This
   activity is largely being driven by diurnal heating under a robust
   anticyclone aloft, aided by localized orographic ascent. Although
   RAP forecast soundings and analyses show sufficient MLCAPE (on the
   order of 500-2000 J/kg) in place across the region, regional radar
   VADs reveal limited deep layer shear. This lack of shear will most
   likely yield unorganized storm clusters with relatively short
   longevity and a limited severe potential. However, the instability
   in place across the region is supporting brief updraft pulses
   capable of producing up to one-inch hail (per recent MRMS
   estimates). Additionally, steep boundary-layer lapse rates between
   8-9 C/km will support a downdraft-driven strong-wind potential
   through at least sunset and the onset of diurnal low-level cooling. 

   The general expectation over the next 1-2 hours is for unorganized
   storms to continue to pose a transient severe threat as they
   propagate to the south/southwest. Additional thunderstorms appear
   likely across the Safford to Willcox, AZ areas where satellite
   imagery shows rapidly deepening cumulus. There is some uncertainty 
   regarding the southwestern extent of the threat due to increasing
   MLCIN over southern and southwest AZ. As such, the strongest storms
   may be limited spatially to the eastern/southeastern portions of AZ.
   Given the anticipated brief nature of the severe-weather threat and
   uncertainty in spatial extent, a watch is not expected.

   ..Moore/Edwards.. 08/20/2020

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

   ATTN...WFO...ABQ...EPZ...TWC...FGZ...PSR...

   LAT...LON   35091193 34791092 33900964 33400851 32660806 31720860
               31140933 31170998 31241080 31551123 32501169 33261216
               34471288 34871274 35091193