ACUS11 KWNS 142042
SWOMCD
SPC MCD 142042
ILZ000-WIZ000-IAZ000-142215-

Mesoscale Discussion 0425
NWS Storm Prediction Center Norman OK
0342 PM CDT Tue Apr 14 2026

Areas affected...Parts of northeast/east-central IA...southwest
WI...and far northwest IL

Concerning...Tornado Watch 109...

Valid 142042Z - 142215Z

The severe weather threat for Tornado Watch 109 continues.

SUMMARY...A swath of very large to giant hail (3+ inches in
diameter) appears likely over the next couple hours, with a few
tornadoes also expected. The tornado risk will continue to increase
through the afternoon into this evening.

DISCUSSION...A dominant right-moving supercell has rapidly
intensified immediately south of a quasi-stationary surface front
extending across central IA, with additional storm splits evolving
along its northern flank. This storm has recent reports of a tornado
and 1.75 inch hail. Ahead of this storm, a strongly unstable air
mass (around 4500 J/kg SBCAPE per modified 18Z DVN special sounding)
and 50 kt of effective shear will favor continued intensification of
this storm and additional storms forming along its flanks and near
the surface boundary over the next few hours. Given a long/mostly
straight hodograph (per VWP data), splitting supercells with
dominant right-movers will pose a risk of very large to giant hail
(some 3+ inches in diameter) and a few tornadoes.

With time, low-level hodographs will increase in size/clockwise
curvature as a low-level jet strengthens through the afternoon into
the evening. This will support an increasing risk of strong to
intense tornadoes with any established semi-discrete supercells.

..Weinman.. 04/14/2026

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

ATTN...WFO...MKX...DVN...ARX...DMX...

LAT...LON   42569317 42829282 42969226 43109053 42998994 42568984
            42248999 42009121 42049267 42289310 42569317

MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN