ACUS11 KWNS 160030
SWOMCD
SPC MCD 160029=20
WIZ000-IAZ000-MNZ000-MOZ000-NEZ000-SDZ000-160230-

Mesoscale Discussion 0730
NWS Storm Prediction Center Norman OK
0729 PM CDT Fri May 15 2026

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

Concerning...Severe Thunderstorm Watch 205...

Valid 160029Z - 160230Z

The severe weather threat for Severe Thunderstorm Watch 205
continues.

SUMMARY...The potential for large hail up to 2.0-2.5" will continue
for the next few hours. With time, the potential for more widespread
damaging winds is expected to increase as thunderstorms consolidate
into a mesoscale convective system. A small temporal window for a
tornado or two may develop prior to that transition across portions
of north-central into northeast Iowa.

DISCUSSION...Semi-discrete to clustering storm modes (including
supercell structures) are being observed as of 00:25 UTC (7:25 PM
CDT) across portions of northwest and north-central IA into southern
MN, with a separate thunderstorm cluster observed over southwest IA.
Large hail up to 1.75" has been observed with the ongoing storms
across northwest and north-central IA, with potentially a greater
damaging wind threat evolving with the southwest IA storm cluster,
where a 74 mph wind gust was recently received.

Latest objective analysis suggests the air mass across eastern NE
into western and central IA remains moderately unstable with
estimated MLCAPE ranging from around 1000 J/kg along the MN-IA
border to as high as 2500 J/kg across southwest IA. The current KOAX
and KDMX VWPs indicate a vertically veering wind profile with 45-50
kt of effective bulk shear. This parameter space will continue to
favor supercell storm modes with an attendant threat for hail up to
2.0-2.5" with any more discrete storms. Otherwise, the continued
increase in storm coverage noted west through north of Fort Dodge,
and from Mason City to the Albert Lea vicinity is expected to
eventually lead to an organized cold pool with a resultant increase
in damaging wind potential. A separate, more organized wind threat
(70-80 mph wind gusts) may also evolve from the ongoing storm
cluster in southwest IA east through the I-80 corridor, south of Des
Moines between 01-02z (8-9 PM CDT).=20

Finally, a small spatiotemporal window for a tornado or two may
evolve across portions of north-central into northeast IA in the
01-02z (8-9 PM CDT) timeframe. This threat will be conditional on
the existence of surface-based storm modes that can overcome the
increasing convective inhibition and realize the rapidly
strengthening low-level shear.

..Mead/Smith.. 05/16/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!7wjcV-JihToFuIKmotsE6ROQMahkhztQ7Erw0o428TlZIBnmOgWesbtOTzPQ2oW0zoOuHICR2= S50FGyABRrmnKdvgEQ$ for graphic product...

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

LAT...LON 40719732 41549728 42309724 42999699 43819586 43859433
44209283 44039170 43229115 42809124 42159230 41589269
41189336 40859410 40569448 40359738 40719732=20

MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN


=3D =3D =3D
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