Storm Prediction Center Mesoscale Discussion 2387

   Mesoscale Discussion 2387
   NWS Storm Prediction Center Norman OK
   0135 PM CDT Wed Oct 21 2026

   Areas affected...Parts of southern and central Arizona

   Concerning...Severe potential...Watch possible 

   Valid 211835Z - 212100Z

   Probability of Watch Issuance...60 percent

   SUMMARY...The severe risk will increase through the afternoon,
   especially between 20Z and 23Z. The primary concerns will be large
   hail and severe wind gusts. A watch may eventually be needed.

   DISCUSSION...The latest visible satellite imagery shows deepening
   boundary-layer cumulus evolving across parts of southern AZ --
   beneath a plume of mid/high-level clouds. Over the next few hours,
   continued differential heating and orographic circulations should
   promote scattered thunderstorm development in the 20Z-23Z time
   frame. The KEMX VWP is sampling an elongated hodograph (40-50 kt of
   0-6 km shear) and modest low-level hodograph curvature (albeit
   weaker low-level shear compared to areas farther north). This,
   combined with the destabilizing PBL, will support
   discrete/semi-discrete supercells and organized clusters. Given the
   expectation for separated updrafts, large to very large hail and
   locally severe gusts will be the primary concerns (though a tornado
   or two cannot be ruled out with any longer-lived supercells). While
   timing is somewhat uncertain, a watch may eventually be needed for
   parts of the area.

   ..Weinman/Mosier.. 10/21/2026

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

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

   LAT...LON   32340968 32401094 32691159 33351273 33641292 33841285
               33971261 34061157 34091105 34040993 33940931 33680912
               33210904 32630916 32340968 

   MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN