Mesoscale Discussion 0194
   NWS Storm Prediction Center Norman OK
   0317 PM CDT Wed Mar 18 2020

   Areas affected...southwest and south-central Arizona

   Concerning...Severe potential...Watch unlikely 

   Valid 182017Z - 182245Z

   Probability of Watch Issuance...5 percent

   SUMMARY...Thunderstorms capable of marginally severe hail and wind
   are possible across southwest and south-central Arizona this
   afternoon and into the evening. Given the marginal severe threat, a
   watch issuance is unlikely.

   DISCUSSION...An upper low spinning over northern Baja California is
   beginning to pivot and will eject northeastward into Arizona this
   evening. As large-scale ascent spreads over southern Arizona, a mix
   of elevated and surface-based storms is expected with a transition
   to surface-based storms likely as surface dewpoints increase to the
   upper 40s and low 50s F. With mid-level lapse rates steepening and
   cold temperatures aloft, marginally severe hail appears to be the
   main threat. Stronger winds aloft could be transported to the
   surface within downdrafts possibly resulting in marginally severe
   winds, especially in areas with a deeper, well-mixed boundary layer.

   A few CG lightning flashes have already been observed in southern
   Arizona with initial convection. Storms will likely develop roughly
   on a northwest-southeast line from near Yuma down the eastern shore
   of the Gulf of California, before pivoting more north-northeastward
   across southwest and south-central Arizona as the upper low begins
   to pivot this afternoon into the evening.

   ..Nauslar/Dial.. 03/18/2020

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

   ATTN...WFO...TWC...PSR...

   LAT...LON   32071366 32381482 32721485 33411451 33751376 33881279
               33671163 32871099 32261083 31661087 31421155 32071366