Mesoscale Discussion 1692
   NWS Storm Prediction Center Norman OK
   0520 PM CDT Sun Jul 21 2024

   Areas affected...portions of south-central Arizona

   Concerning...Severe Thunderstorm Watch 558...

   Valid 212220Z - 212345Z

   The severe weather threat for Severe Thunderstorm Watch 558
   continues.

   SUMMARY...Scattered thunderstorms over higher terrain could move
   south and will remain capable of damaging gusts this afternoon and
   into the evening.

   DISCUSSION...Radar imagery shows scattered thunderstorms have
   developed across the higher terrain of central AZ this afternoon.
   Despite only modest deep-layer shear profiles, large inverted-v
   thermodynamic profiles have allowed strong downdrafts to develop.
   These high-based storms have already produced several measured
   severe gusts within the higher terrain. While the initial cores have
   moved little and begun to weaken, outflow has moved south/southwest
   ahead of the initial convection evident in regional surface obs.
   Damaging gusts will remain possible as the outflow moves into the
   north/east sides of the Phoenix Metro in the next 1-2 hours.
   Additional storm development will remain possible along/ahead of the
   outflow as it encounters upper 50s to low 60s F dewpoints and
   moderate buoyancy in the lower elevations. Confidence in the exact
   convective evolution is somewhat low owing to modest flow aloft and
   chaotic storm interactions, but any storms able to move off the
   terrain with surging outflow will remain capable of damaging gusts
   into this evening.

   ..Lyons.. 07/21/2024

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

   ATTN...WFO...TWC...FGZ...PSR...VEF...

   LAT...LON   33020998 32760987 32710993 32521017 32491052 32541209
               32551218 32681324 33451332 34311348 35131332 34211171
               33581066 33211015 33020998