Storm Prediction Center Mesoscale Discussion 1439

   Mesoscale Discussion 1439
   NWS Storm Prediction Center Norman OK
   0110 PM CDT Thu Jul 02 2026

   Areas affected...northeast Iowa and far southwest Wisconsin

   Concerning...Severe Thunderstorm Watch 437...

   Valid 021810Z - 021945Z

   The severe weather threat for Severe Thunderstorm Watch 437
   continues.

   SUMMARY...The severe weather threat continues this afternoon across
   northeast Iowa.

   DISCUSSION...A cluster of storms has congealed across northern Iowa
   with a recent measured wind gust of 72 mph near Mason City, Iowa.
   Expect some southward preference of this cluster along the
   instability gradient through the afternoon. In addition, storms are
   starting to develop along the outflow boundary ahead of this
   cluster. These storms may also develop supercell characteristics
   considering 35 to 40 knots of mid-level flow sampled by the KARX
   VWP. These cells and the potential for further upscale growth as
   these storms congeal, will lead to an increasing damaging wind
   threat this afternoon across northeast Iowa and perhaps into far
   southwest Wisconsin. 

   Easterly low-level flow north of the boundary and heating across
   this boundary could result in a narrow zone north of the outflow
   with some tornado potential. However, the low-level jet is quite
   weak (less than 20 knots below 2km per area VWPs) which would limit
   a greater threat.

   ..Bentley/Hart.. 07/02/2026

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

   ATTN...WFO...MKX...DVN...ARX...DMX...

   LAT...LON   43299329 43469257 43469024 43219001 42508990 41878995
               41869140 41809299 42619363 43299329 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN