ACUS11 KWNS 231613
SWOMCD
SPC MCD 231613=20
MNZ000-IAZ000-MOZ000-NEZ000-KSZ000-SDZ000-231815-

Mesoscale Discussion 0501
NWS Storm Prediction Center Norman OK
1113 AM CDT Thu Apr 23 2026

Areas affected...eastern Nebraska...western and central Iowa into
southern Minnesota

Concerning...Severe potential...Watch likely=20

Valid 231613Z - 231815Z

Probability of Watch Issuance...80 percent

SUMMARY...Thunderstorm development is likely along the cold front
from midday into early this afternoon across eastern NE into
northwest IA. A mix of supercells and line segments could support
tornadoes, large hail, and damaging gusts. A Weather Watch is
likely.

DISCUSSION...As of 1600 UTC, morning visible imagery showed initial
ACCAS deepening along the cold front analyzed from western MN into
northwest IA and eastern NE. Mid-level ascent associated with an
upper trough over the western Dakotas was evident overspreading the
front with an increase in cumuliform cloud structures on visible
imagery. A prominent dry slot has also helped erode residual cloud
cover from west to east, resulting in an increase in diurnal
heating. The net result has been surface warming and reduction in
residual inhibition on area model soundings. Sufficient
boundary-layer moisture (dewpoints in the low to mid 60s F) in
conjunction with the warming and ascent is supporting gradual
destabilization with MLCAPE of 1000-2000 J/kg.

As the upper trough and mid-level ascent continues eastward, flow
aloft will strengthen. Initial thunderstorm development is likely by
midday into early this afternoon over eastern NE and western IA.
Morning RAOBs and the arrival of the upper trough will contribute to
moderate deep-layer shear amidst veering wind profiles, supporting a
mixed mode of supercells and line segments. Large buoyancy and cool
mid-level temperatures suggest hail is likely with the initial
storms. Low-level shear is also sufficient for a few tornadoes,
especially with the more semi-discrete supercells.

Initial frontal forcing is expected to result in scattered to
widespread storm coverage. However, the cold front motion is
relatively modest (080/15 kt) and should allow convection to move
off the boundary and remain semi-discrete. With time, upscale growth
into one or more linear clusters is likely. This would support a
risk for damaging gust and a few embedded tornadoes. Given the
expected increase in storm coverage within a favorable environment,
a Tornado Watch is likely in the next couple of hours.

..Lyons/Guyer.. 04/23/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!7F5zU1-km8IiimiOvKq9vAiimKRjbI0pEk_bMONFlELJrtQcmKcDFfVs9cNJQ1z1TWJKsmrTI= shQeoPdGcByOh3IOnA$ for graphic product...

ATTN...WFO...ARX...MPX...DMX...EAX...FSD...OAX...TOP...GID...

LAT...LON 44439567 44879515 44899419 44519319 43609299 41859386
40029539 39779672 39889736 40029759 40399753 41329710
42259660 44089603 44439567=20

MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN


=3D =3D =3D
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