827
ACUS11 KWNS 240200
SWOMCD
SPC MCD 240159
IAZ000-ILZ000-MOZ000-240330-

Mesoscale Discussion 0513
NWS Storm Prediction Center Norman OK
0859 PM CDT Thu Apr 23 2026

Areas affected...Central to eastern Iowa

Concerning...Severe Thunderstorm Watch 138...

Valid 240159Z - 240330Z

The severe weather threat for Severe Thunderstorm Watch 138
continues.

SUMMARY...A squall line is beginning to weaken across central Iowa,
but some severe threat may extend downstream into eastern Iowa. A
watch has been issued to address this concern.

DISCUSSION...Lightning counts and vertically integrated liquid
trends continue to decline withing a squall line moving across
central IA. Additionally, KDMX imagery depicts portions of the line
starting to become outflow dominant. However, downstream low-level
wind shear (25-30 knots 0-1 km BWD) remains favorable for localized
bowing segments that may produce embedded circulations and/or swaths
of severe winds. This threat will most likely manifest where ever
the updraft/downdraft convergence zone can remain balanced and
support strong updrafts atop the low-level convergence zone.
Consequently, some localized severe wind and brief tornado threat
may linger downstream into eastern IA over the next few hours where
dewpoints remain in the low 60s and MLCAPE remains near 1000 J/kg.

..Moore.. 04/24/2026

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

ATTN...WFO...DVN...DMX...EAX...

LAT...LON   40649365 41739287 42049259 42139237 42159168 42099103
            41909067 41729060 41459081 40559163 40469265 40479323
            40519355 40649365

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