Mesoscale Discussion 1776
   NWS Storm Prediction Center Norman OK
   0656 PM CDT Sun Sep 11 2022

   Areas affected...Parts of south-central Arizona

   Concerning...Severe potential...Watch unlikely 

   Valid 112356Z - 120130Z

   Probability of Watch Issuance...5 percent

   SUMMARY...A couple instances of marginal hail and strong to locally
   severe gusts will be possible into the early evening hours.

   DISCUSSION...The latest radar data from KEMX depicts isolated
   discrete cells evolving south of Tuscon AZ, where upper 50s
   dewpoints beneath modest midlevel lapse rates are contributing to
   moderate surface-based instability. This activity is developing
   along the eastern periphery of 25-30 kt southerly midlevel flow (per
   regional VWP), which is resulting in 20-30 kt effective shear.
   RAP/NAM forecast hodographs depict modest clockwise-turning in the
   low/mid-levels, which combined with weak large-scale ascent over the
   area could favor discrete/semi-discrete convection with transient
   updraft rotation. The primary concern with this activity will be a
   couple instances of sporadic marginal hail and perhaps strong to
   locally severe downdraft winds aided by a deeply mixed boundary
   layer. Any severe threat should remain localized and marginal.

   ..Weinman/Thompson.. 09/11/2022

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

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

   LAT...LON   31231109 31731255 31921311 32741322 33121301 33171254
               33061177 32811104 32331044 32001025 31291038 31231109