SPC MD 1439
MD 1439 CONCERNING SEVERE THUNDERSTORM WATCH 437... FOR NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN

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

Read more
https://www.spc.noaa.gov/products/md/md1439.html