Mesoscale Discussion 2284
NWS Storm Prediction Center Norman OK
0658 PM CST Sun Dec 28 2025

Areas affected...central Indiana...western Kentucky and
Tennessee...extreme southern Illinois

Concerning...Tornado Watch 643...

Valid 290058Z - 290400Z

The severe weather threat for Tornado Watch 643 continues.

SUMMARY...Areas of damaging gusts or perhaps a brief tornado remain
possible from central Indiana southwestward into the lower Ohio
Valley. Sporadic damaging gusts cannot be ruled out as far south as
western Tennessee.

DISCUSSION...A line of thunderstorms continues to move rapidly east
coincident with the cold front, with indications of QLCS storm mode
at times. Convective trends may be dwindling across the far northern
areas, as the line encounters a relatively cooler boundary layer.
Farther south toward the OH River and toward western KY and TN,
temperatures remain in the 70s F with lower 60s F dewpoints. This is
generally resulting in MLCAPE values of a few hundred J/kg. However,
little instability is needed to persist the damaging wind threat as
the line is strongly forced and with 50 kt around 1 km AGL.
Low-level SRH is also strong with 0-1 km values to 400 m2/s2.

Given the loss of heating and rapidly moving cold front, the severe
storms risk is expected to last a few hours until the line pushes
through the narrow instability axis. In the near term, the greatest
risk areas continues to be within the tornado watch extending from
central IN into western KY, and the watch may be locally extended in
time or space as conditions warrant.

..Jewell.. 12/29/2025

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

ATTN...WFO...ILN...LMK...OHX...IND...PAH...MEG...

LAT...LON   36048994 37408883 38448738 39798622 40208580 40198535
            39688521 38788545 37978603 36698737 35938842 35718910
            35708968 35888995 36048994 

MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN

Mesoscale Discussion 2283
NWS Storm Prediction Center Norman OK
0553 PM CST Sun Dec 28 2025

Areas affected...Central Minnesota into northern Iowa

Concerning...Blizzard 

Valid 282353Z - 290500Z

SUMMARY...Blizzard conditions are expected to gradually increase
through the evening across portions of the Upper Midwest. 30-40 mph
sustained westerly winds will coincide with increasing snowfall
rates, resulting in reduced visibility, perhaps below a quarter
mile, in some instances.

DISCUSSION...Mesoanalysis indicates that the surface low, currently
at 993 mb and located over southern Lake Michigan, is continuing to
deepen while gradually drifting to the northeast. In response to
surface low intensification is a broadening and gradual
strengthening of the west-northwesterly surface wind field within
the low's northwestern quadrant. Surface observations show
widespread 30+ mph sustained wind speeds across much of western MN
into central IA. Meanwhile deep-layer cold air advection, and the
advection of mid-level moisture around the surface low, is resulting
in a broad band of snow pivoting around the low's northwestern
quadrant. As a result, moderate to perhaps occasionally heavy
snowfall rates will coincide with the 30+ mph west-northwesterly
surface wind field, which may strengthen further in tandem with the
low. Increasingly common blizzard conditions may manifest, with
reduced visibility down to or below a quarter mile where the heavier
snow bands and wind gusts may overlap.

..Squitieri.. 12/28/2025

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

ATTN...WFO...DVN...ARX...MPX...DMX...FSD...

LAT...LON   45619391 45769447 45819518 45589575 45089579 44559551
            43319451 42079333 41909267 42159195 42609141 43149124
            43629149 44089188 44729280 45619391