ACUS02 KWNS 160559
SWODY2
SPC AC 160557

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1257 AM CDT Thu Apr 16 2026

Valid 171200Z - 181200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF OKLAHOMA...KANSAS...MISSOURI...IOWA...ILLINOIS...FAR SOUTHEAST
MINNESOTA...AND WISCONSIN...

...SUMMARY...
Widespread severe thunderstorms are expected from parts of the
southern Plains to the Middle and Upper Mississippi Valley vicinity
Friday into Friday night. Tornadoes, possibly strong, very large
hail, and swaths of damaging winds will be possible.

...Southern Plains to Upper Midwest...

A potent upper trough from is expected to eject over the Plains and
Upper Midwest on Friday. Strong deep-layer southwesterly flow will
overspread the region early in the forecast period, with 850-700 mb
flow around 40-50 kt common from parts of OK/KS into WI. At the
surface, forecast guidance has trended a bit further north with the
position of a surface low Friday morning. This low is expected to be
located along the MO River near the SD/IA/NE border, and will
develop northeast into northern WI/MI U.P. by late afternoon. A
trailing cold front will push southeast across Upper MS/Mid-MO
Valley as this occur, becoming oriented from central MI to northwest
MO and southeast KS by 00z. Meanwhile, a second low is forecast to
develop over the TX Panhandle/western OK within strong heating near
a dryline extending southwest from western OK into
west-central/western TX. Ahead of these surface features, a
seasonally moist airmass will be in place, or, in the case of the
Upper Midwest, rapidly advect northward during the morning hours.

A plume of steep midlevel lapse rates, supported by cool to cold
temperatures aloft (near -16 C at 500 MB across portions of IA/MN/WI
at 21z, and -14 to -12 C further southwest) will overspread the
moist boundary layer. This will result in strong destabilization,
with MLCAPE around 2500-3500 J/kg expected across the warm sector.
This kinematic and thermodynamic environment will support robust
convective development near the Upper Midwest surface low
southwestward along the cold front into KS by midday. Initial
supercells are possible, especially closer to the surface low in the
Upper Midwest, and near the triple point/dryline in northwest
OK/south-central KS. More rapid upscale growth into a robust
line/LEWP is expected along the cold front from parts of IA into MO
and eastern KS. Given robust instability and very steep lapse rates,
significant damaging wind swaths will be possible. Additionally,
large to very large hail will be possible with any discrete
supercells, and possibly within line-embedded supercells. Low-level
wind profiles will also support a aerially extensive tornado risk,
both with QLCS mesovortex circulations, and with discrete
supercells. A corridor of perhaps greater tornado risk/coverage may
develop near the surface low from northeast IA into central WI.
Low-level SRH will be maximized in this area and forecast soundings
indicate large, curved hodographs becoming elongated above 2-3 km.
Furthermore, mixing ratios near 14 g/kg and very steep lapse rates
should support robust updrafts with low cloud bases. This are may
become a focused corridor for stronger tornadoes.

Linear convection should continue east across the MS River and Lake
Michigan during the evening and overnight hours, with a gradually
waning severe risk into portions of central/southern IL, Lower MI
and IN. Additional convection may develop during the evening and/or
overnight across parts of TX near the dryline, though this scenario
is more conditional. If storms do develop, large will be the main
risk.

..Leitman.. 04/16/2026

$$