ACUS11 KWNS 040133
SWOMCD
SPC MCD 040133=20
INZ000-ILZ000-IAZ000-040330-

Mesoscale Discussion 1482
NWS Storm Prediction Center Norman OK
0833 PM CDT Fri Jul 03 2026

Areas affected...Far eastern Iowa into northern Illinois

Concerning...Severe Thunderstorm Watch 451...

Valid 040133Z - 040330Z

The severe weather threat for Severe Thunderstorm Watch 451
continues.

SUMMARY...Although MCS intensity has been lackluster thus far,
sporadic severe winds remain possible across far eastern Iowa into
northern Illinois.

DISCUSSION...Over the past hour, a loosely organized MCS has emerged
across far eastern IA into northwest IL. However, a prominent
outflow boundary is evident from KDVN surging ahead of the primary
convective cores. Despite favorable buoyancy downstream and only
gradually increasing MLCIN with the onset of nocturnal cooling,
regional 00 UTC RAOBs and recent VWP observations show 20 knot
southwesterly deep-layer wind shear vectors, oriented mainly
parallel to the axis of convection. Additionally, very weak
low-level winds are noted, which is also promoting outflow-dominant
storms. Despite these trends, occasional bursts of strong/severe
winds have been evident in velocity data, primarily as new updrafts
develop and collapse within and ahead of the line. This trend should
continue through the next few hours as the band gradually shifts east/southeast.=20

In the short-term (next 1-2 hours), somewhat higher confidence in
severe winds will be focused on the northern fringe of the line
where better orientation to the deep-layer shear vector has allowed
for a more balanced updraft/downdraft convergence zone. This section
of the line will likely continue to propagate east/northeast into
northeast IL where temperatures have recovered into the low 80s
ahead of the band.

..Moore.. 07/04/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!5kOzoaBWpZXyVqqPA0oTWSOYBzDUoQt9CKRj5RxGymobmXwz8EMukXrwRKAxvJK98BJ24V9ge= ul7WAWL-i5dnIFuLI0$ for graphic product...

ATTN...WFO...LOT...ILX...DVN...

LAT...LON 41329178 42058971 42368878 42378820 42298778 41958753
41688748 41378751 41158762 40988806 40888849 40899144
40929165 41009182 41159192 41329178=20

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN


=3D =3D =3D
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* Origin: Capitol City Weather Station (1:2320/127)