ACUS11 KWNS 272055
SWOMCD
SPC MCD 272055=20
ILZ000-MOZ000-272300-

Mesoscale Discussion 0574
NWS Storm Prediction Center Norman OK
0355 PM CDT Mon Apr 27 2026

Areas affected...south-central through east-central Missouri into
southwest Illinois

Concerning...Tornado Watch 160...

Valid 272055Z - 272300Z

The severe weather threat for Tornado Watch 160 continues.

SUMMARY...The threat for all severe-weather hazards --including the
potential for strong tornadoes-- is expected to increase late this
afternoon into evening.

DISCUSSION...Recent trends in surface observations and radar data
indicate the outflow boundary south of the St. Louis metropolitan
area stalling with the western extent of that feature lifting north
in the Columbia, MO vicinity. PBL warming and moistening to the
north of the modifying boundary is resulting in rapid air mass
recovery within a kinematic environment featuring locally backed
surface winds with As such, rapid air mass recovery is ongoing along
to the north of the retreating outflow, which is coincident with a
corridor of enhanced low-level shear with effective SRH of 200-300
M2/s2.=20

The supercell ongoing to the immediate north of the St. Louis metro
is within the eastern fringe of the stronger destabilization amidst
a kinematic environment featuring around 250 m2/s2 of effective SRH
and around 60 kt of effective bulk shear. As such, the potential for
tornadoes will exist with that storm, at least in the near-term. The longer-term tornado threat with that storm will be contingent on
sufficient destabilization of the downstream air mass to the north
of the fresher segment of convective outflow.=20

At the same time, thunderstorms are increasing in areal coverage
along and ahead of a cold front moving through northwest and
west-central MO, where low-level winds have veered to southwesterly.
The leading edge of those storms will pose the greatest risk for
tornadoes as the continue northeast and encounter increasingly
stronger low-level shear near and to the north of the Columbia and
Mexico, MO vicinities.

In addition to the tornado threat, the potential for large to very
large hail will exist with any sustained supercells. Isolated
damaging wind gusts also remain possible.

..Mead.. 04/27/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!54WOf28MJB-tHdmy7JApeRifSsgQFnLI9nyinZ04JyVUa7TKbz4TPMdQh6DGSLO2PdytV7Xbd= XmlcGkEDXC53fwytKA$ for graphic product...

ATTN...WFO...ILX...LSX...SGF...

LAT...LON 37549338 38449280 39039228 39589173 39559093 39448977
39108902 38648892 38378953 37929032 37339128 36939162
36699225 36849270 37149328 37549338=20

MOST PROBABLE PEAK TORNADO INTENSITY...140-170 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN


=3D =3D =3D
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