ACUS11 KWNS 150132
SWOMCD
SPC MCD 150132
ILZ000-WIZ000-IAZ000-150300-

Mesoscale Discussion 0436
NWS Storm Prediction Center Norman OK
0832 PM CDT Tue Apr 14 2026

Areas affected...Northern Illinois and southeast Wisconsin

Concerning...Tornado Watch 109...

Valid 150132Z - 150300Z

The severe weather threat for Tornado Watch 109 continues.

SUMMARY...The tornado risk will focus on northern Illinois with QLCS
circulations still possible farther north. Damaging wind potential
will be greatest with linear storm modes.

DISCUSSION...The strongest activity in WW 109 exists in northern
Illinois. With the low-level jet focusing in this area (50+ kts
noted on KDVN and KLOT VAD), moist inflow and strong low-level shear
will support a threat for tornadoes (possibly strong) as well as
damaging winds and isolated large hail. Storm interactions have thus
far limited how organized low-level mesocyclones have become, but
the environment is quite favorable.

In southeast Wisconsin, convection has been much more linear. A line
segment moving toward Milwaukee is favorably oriented with the deep
layer shear vector. Damaging winds are still possible, but the
impacts of earlier supercell outflow may modulate this threat to
some extent. The KMKX VAD still shows sufficient low-level shear
that QLCS circulations may also occur at the leading edge of the
convective line.

..Wendt.. 04/15/2026

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

ATTN...WFO...LOT...MKX...DVN...

LAT...LON   42119019 42299015 42418997 42498954 42558927 42698900
            43168829 43088785 42698776 42198779 42098832 42119019

MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN