WW 643 TORNADO IL IN KY MO 282045Z - 290200Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 643
NWS Storm Prediction Center Norman OK
345 PM EST Sun Dec 28 2025
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Southern and Central Illinois
Western and Central Indiana
Western Kentucky
Far Southeast Missouri
* Effective this Sunday afternoon and evening from 345 PM until
900 PM EST.
* Primary threats include...
A couple tornadoes possible
Scattered damaging winds likely with isolated significant gusts
to 75 mph possible
SUMMARY...A broken line of thunderstorms will move quickly
east-northeastward this afternoon and evening while posing a threat
for scattered severe/damaging winds up to 65-75 mph and a couple of
tornadoes.
The tornado watch area is approximately along and 80 statute miles
east and west of a line from 40 miles north northwest of Lafayette
IN to 5 miles southeast of Paducah KY. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU3).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.
&&
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1 inch. Extreme turbulence and surface wind
gusts to 65 knots. A few cumulonimbi with maximum tops to 400. Mean
storm motion vector 26045.
...Gleason
WW 0643 Status Updates
STATUS FOR WATCH 0643 HAS NOT BEEN ISSUED YET
MD 2280 CONCERNING HEAVY SNOW FOR SOUTHEAST MINNESOTA INTO NORTHWEST/NORTHERN WISCONSIN
Mesoscale Discussion 2280
NWS Storm Prediction Center Norman OK
1240 PM CST Sun Dec 28 2025
Areas affected...Southeast Minnesota into northwest/northern
Wisconsin
Concerning...Heavy snow
Valid 281840Z - 290045Z
SUMMARY...Conditions will initially be marginal for heavier snowfall
rates, but cooling temperatures at the surface and aloft will
increase potential for snowfall rates to around 1 inch per hour.
DISCUSSION...As the mid-level jet intensifies in the central Plains,
a surface low continues to deepen in northern Illinois. Cold air
advection is increasing within the upper Mississippi Valley in
response. Furthermore, deep-layer lift is also increasing as
evidenced by a broad area of precipitation moving into parts of
northwest/northern Wisconsin. While temperatures in some areas have
been just above freezing for most of the morning, recent surface
observations have shown decreasing temperatures/dewpoints. Dynamic
cooling within the heavier precipitation bands has also been
evident. That said, snowfall should increase through the afternoon.
Observations from Eau Claire and Hayward already show moderate
snowfall occurring. As the atmospheric profile continues to cool,
the environment should become more favorable for snowfall rates up
to around 1 inch per hour through late afternoon/early evening.
..Wendt.. 12/28/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MQT...GRB...DLH...ARX...MPX...
LAT...LON 46479079 46509029 46298948 46128922 45778928 44679108
44269186 44049236 43999277 44059292 44669282 45029257
45429221 46059139 46479079
MD 2278 CONCERNING HEAVY SNOW FOR NORTH CENTRAL IOWA...SOUTHERN AND EASTERN MINNESOTA AND NORTHWESTERN WISCONSIN
Mesoscale Discussion 2278
NWS Storm Prediction Center Norman OK
0952 AM CST Sun Dec 28 2025
Areas affected...North central Iowa...southern and eastern Minnesota
and northwestern Wisconsin
Concerning...Heavy snow
Valid 281552Z - 282145Z
SUMMARY...Heavy snow, with rates near 1 inch per hour, is expected
to develop by midday in east central Minnesota and northwest
Wisconsin. Occasional blizzard conditions are expected into
southern Minnesota and northern Iowa.
DISCUSSION...Gradual erosion of a warm nose (noted in the 12z MPX
sounding) will continue through the afternoon from eastern MN into
northwest WI as a result of strengthening ascent and
cooling/saturation of profiles to the northwest of a deepening
cyclone now near the IA/MO/IL border. Near-surface cooling from
northwest-to-southeast will become more favorable for
accumulating/heavy snow from east central MN into northwest WI
within the primary deformation band, while snowfall rates will be
lower farther southwest into southern MN/northern IA. However, a
strengthening pressure gradient and rapidly falling temperatures
into the teens/single digits will result in blowing snow and
blizzard conditions (frequent gusts 35-50 mph with visibility
reduced to 1/4 mi or less) from southern MN/northern IA through the
afternoon.
..Thompson.. 12/28/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DLH...ARX...MPX...DMX...FSD...
LAT...LON 44149300 43569311 43169339 42899399 42959490 43549539
44319536 45199483 46129356 46609234 46829155 46809116
46409115 46039152 45179278 44709305 44149300
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1040 AM CST Sun Dec 28 2025
Valid 281630Z - 291200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
EASTERN ILLINOIS INTO INDIANA AND WESTERN KENTUCKY...
...SUMMARY...
Scattered severe thunderstorms are possible over parts of the
Midwest and lower Ohio Valley this afternoon through the evening.
Severe/damaging wind gusts and a couple of tornadoes are the primary
threats.
...Mid Mississippi Valley into the Midwest/Ohio Valley...
An upper trough/low over the northern Plains this morning will
further intensify today as it develops towards the Upper
Midwest/Great Lakes through the period. Pronounced large-scale
ascent associated with a strengthening mid/upper jet (100-120 kt at
500 mb) over the mid MS Valley into IL/IN will encourage rapid
deepening of a surface low as it develops from central/northern IL
into Lower MI by this evening. A rather moist low-level airmass with
generally upper 50s to low 60s surface dewpoints will continue to
spread northward across the mid MS Valley into parts of the
Midwest/OH Valley and southern Great Lakes regions in tandem with a
northward-shifting surface warm front. A cold front is also expected
to sweep east-southeastward across these regions this
afternoon/evening as the surface low tracks northeastward. This cold
front should serve as a focus for strong to severe convection later
today.
The 12Z ILX sounding showed a moist but saturated profile through
much of the troposphere, with strong west-southwesterly
mid/upper-level winds already present over the warm sector. Current
expectations are for ongoing, mostly elevated convection across
central IL to pose a threat for isolated hail and strong to locally
severe gusts given the strength of the mid-level flow. This activity
may linger along/just north the warm front through the afternoon as
it spreads quickly east-northeastward into IN. Additional
thunderstorms are expected to form along/near the cold front across
IL and vicinity by 20-22Z as modest/filtered daytime heating occurs,
with come cloud breaks already noted in visible satellite imagery
across east-central MO/south-central IL. It does appear that surface
temperatures are warming faster/more than forecast by some guidance
across the warm sector in IL, with 16Z observations at some stations
already reaching into the upper 60s/low 70s.
The more aggressive 12Z guidance and recent RAP runs suggest that
around 500-1000 J/kg of MLCAPE may ultimately develop in a narrow
corridor across eastern IL and western IN/KY ahead of the front,
even though modest lapse rates aloft will likely inhibit more robust
destabilization. This weak instability should be sufficient to
support organized updrafts, as both low-level and deep-layer shear
will be quite strong owing to the strengthening wind profiles across
the warm sector this afternoon/evening with the approaching
mid/upper-jet. There is still some uncertainty regarding the
potential for pre-frontal convection. But, any low-topped supercells
that can form and be sustained should pose a threat for a couple of
tornadoes with upwards of 200-250 m2/s2 of effective SRH present.
Eventual development of a thin/forced line of convection along the
cold front appears likely, with a threat for scattered
severe/damaging winds and perhaps a couple of embedded tornadoes. At
least an isolated severe threat may persist this evening/tonight
across the OH Valley and parts of western PA, where low-level flow
is forecast to remain quite strong even with minimal instability.
..Gleason/Wendt.. 12/28/2025
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0146 PM CST Sun Dec 28 2025
Valid 282000Z - 291200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
ILLINOIS...WESTERN KENTUCKY AND INDIANA...
...SUMMARY...
Scattered severe thunderstorms are possible over parts of the
Midwest and lower Ohio Valley this afternoon through the evening.
Severe/damaging wind gusts and a couple of tornadoes are the primary
threats.
...20Z Update...
The only change to the outlook for this issuance is to trim the
Marginal Risk area across parts of north-central Illinois behind a
cold front that is moving southeastward across the region.
..Broyles.. 12/28/2025
.PREV DISCUSSION... /ISSUED 1040 AM CST Sun Dec 28 2025/
...Mid Mississippi Valley into the Midwest/Ohio Valley...
An upper trough/low over the northern Plains this morning will
further intensify today as it develops towards the Upper
Midwest/Great Lakes through the period. Pronounced large-scale
ascent associated with a strengthening mid/upper jet (100-120 kt at
500 mb) over the mid MS Valley into IL/IN will encourage rapid
deepening of a surface low as it develops from central/northern IL
into Lower MI by this evening. A rather moist low-level airmass with
generally upper 50s to low 60s surface dewpoints will continue to
spread northward across the mid MS Valley into parts of the
Midwest/OH Valley and southern Great Lakes regions in tandem with a
northward-shifting surface warm front. A cold front is also expected
to sweep east-southeastward across these regions this
afternoon/evening as the surface low tracks northeastward. This cold
front should serve as a focus for strong to severe convection later
today.
The 12Z ILX sounding showed a moist but saturated profile through
much of the troposphere, with strong west-southwesterly
mid/upper-level winds already present over the warm sector. Current
expectations are for ongoing, mostly elevated convection across
central IL to pose a threat for isolated hail and strong to locally
severe gusts given the strength of the mid-level flow. This activity
may linger along/just north the warm front through the afternoon as
it spreads quickly east-northeastward into IN. Additional
thunderstorms are expected to form along/near the cold front across
IL and vicinity by 20-22Z as modest/filtered daytime heating occurs,
with come cloud breaks already noted in visible satellite imagery
across east-central MO/south-central IL. It does appear that surface
temperatures are warming faster/more than forecast by some guidance
across the warm sector in IL, with 16Z observations at some stations
already reaching into the upper 60s/low 70s.
The more aggressive 12Z guidance and recent RAP runs suggest that
around 500-1000 J/kg of MLCAPE may ultimately develop in a narrow
corridor across eastern IL and western IN/KY ahead of the front,
even though modest lapse rates aloft will likely inhibit more robust
destabilization. This weak instability should be sufficient to
support organized updrafts, as both low-level and deep-layer shear
will be quite strong owing to the strengthening wind profiles across
the warm sector this afternoon/evening with the approaching
mid/upper-jet. There is still some uncertainty regarding the
potential for pre-frontal convection. But, any low-topped supercells
that can form and be sustained should pose a threat for a couple of
tornadoes with upwards of 200-250 m2/s2 of effective SRH present.
Eventual development of a thin/forced line of convection along the
cold front appears likely, with a threat for scattered
severe/damaging winds and perhaps a couple of embedded tornadoes. At
least an isolated severe threat may persist this evening/tonight
across the OH Valley and parts of western PA, where low-level flow
is forecast to remain quite strong even with minimal instability.
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1118 AM CST Sun Dec 28 2025
Valid 291200Z - 301200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Aside from parts of the lower Rio Grande Valley, the risk for
thunderstorms appears negligible across much of the U.S. Monday
through Monday night.
...Discussion...
Within one branch of westerlies emanating from the northern
mid-latitude Pacific, models indicate that broad mid-level ridging
will be maintained across British Columbia and the Pacific Northwest
through the Canadian/northern U.S. Rockies and adjacent
Prairies/Great Plains through this period. Downstream troughing may
undergo further amplification as a surface cold intrusion progresses
south/southeastward through the Gulf Basin. However, the primary
embedded short wave perturbation is forecast to rapidly pivot east
and northeast of the lower Great Lakes and Ohio Valley toward the
Canadian Maritimes and northwestern Atlantic Monday through Monday
night. While the center of an associated broad, slowly deepening
and occluding surface cyclone shifts east-northeast of Lake
Huron/Georgian Bay through southern Quebec, it appears a secondary
surface low may develop across northern New England into the lower
St. Lawrence Valley. In its wake, the trailing cold front is
forecast to rapidly advance east/southeast of the Appalachians, and
well offshore of much of the Atlantic Seaboard by 12Z Tuesday.
....Lower Great Lakes into New England...
NAM and Rapid Refresh forecast soundings indicate that
lower/mid-tropospheric warming and moistening, preceding the
secondary surface frontal wave development, will contribute to weak
elevated destabilization across portions of eastern New York state
through New England during the day Monday. This may contribute to
deeper convective development embedded within an evolving broader
precipitation shield. The extent to which this could become capable
of producing lightning remains a bit unclear, but probabilities for
weak thunderstorms still seem best characterized as less than 10
percent.
...Lower Rio Grande Valley...
NAM and Rapid Refresh forecast soundings, and other model output,
suggest that widely scattered weak thunderstorm activity is possible
along or just behind the cold front as it advances across Deep South
Texas late tonight. Timing of the frontal passage and associated
convection through the lower Rio Grande around Brownsville remains
uncertain, but low thunderstorm probabilities may linger an hour or
two beyond 12Z Monday.
..Kerr.. 12/28/2025
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
1244 PM CST Sun Dec 28 2025
Valid 301200Z - 311200Z
...NO THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Thunderstorm probabilities appear less than 10 percent across the
U.S. for Tuesday through Tuesday night.
...Discussion...
Models indicate that the center of a broad and still deepening
cyclone will migrate north-northwest of the St. Lawrence Valley,
toward the southern Hudson Bay vicinity through this period. At
mid-levels, it appears that the broadening circulation will be
reinforced by a vigorous short wave perturbation digging from the
higher latitudes. Surrounding this low, cyclonic flow will likely
encompass most areas east of the Rockies through the offshore
western Atlantic, with some further amplification across the Gulf
Basin into the Caribbean and Bahamas. Beneath this regime, cool
surface ridging entrenched across much of the southern Great Plains,
Gulf Coast and Gulf Basin is forecast to only slowly begin to
weaken.
Upstream, a cyclonic circulation over the subtropical eastern
Pacific may gradually begin to consolidate in advance of more
notable short wave troughing digging across the mid-latitude eastern
Pacific. However, a substantive northeastward acceleration of the
low toward the California coast appears unlikely through at least
early Wednesday, and mid-level ridging will generally be maintained
across much of the interior West. While lower/mid-tropospheric
moisture return emanating from the lower latitude eastern Pacific
may overspread portions of the Southwest into Great Basin, it is
still not clear that this will yield sufficient destabilization to
support convection capable of producing lightning (although NAM
forecast soundings around the Las Vegas, NV vicinity late Tuesday
evening/overnight suggest that this might not be completely out of
the question).
..Kerr.. 12/28/2025
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1050 AM CST Sun Dec 28 2025
Valid 281700Z - 291200Z
The ongoing forecast and meteorological reasoning remains largely on
track. The biggest change was trim areas along the northwest and
north-central of the elevated where temperatures have already fallen
into the 30s, which will temper minimum relative humidity across
these areas. Elsewhere, strong gusty winds and relative humidity in
the 20-30% range will support elevated fire weather conditions.
..Marsh.. 12/28/2025
.PREV DISCUSSION... /ISSUED 1254 AM CST Sun Dec 28 2025/
...Synopsis...
A pronounced mid-level trough will traverse the central U.S. today,
supporting the eastward advancement of a surface low and associated
cold front sweeping across the MS Valley during the day. Strong
northwesterly surface flow will overspread the Plains states,
resulting in cooler temperatures but dry and windy conditions.
Across portions of the southern Plains, behind the cold front, 25+
mph sustained northwesterly surface winds will prevail for several
hours atop dry fuels. Despite 25-35 percent RH, the aforementioned
combination of modestly dry fuels, and strong sustained winds, will
yield high-end Elevated conditions for western and northern Texas
into Oklahoma during the 18Z-00Z (Noon to 6 PM CST) time frame.
...Please see www.spc.noaa.gov/fire for graphic product...
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1246 PM CST Sun Dec 28 2025
Valid 291200Z - 301200Z
An elevated area was added across portions of the Southeast,
southern Appalachians, and North Carolina. In the wake of a strong
surface-cold front, a drier and windier airmass will overspread the
Southeast. Although meteorologically elevated fire weather
conditions will take hold across much of the area, the recent influx
of Gulf moisture ahead the strong cold front has tempered the
seasonally adjusted ERC percentiles, especially farther west across
Mississippi and Alabama. As such, for this forecast period,
highlights will focus on regions where seasonally adjusted ERC
percentiles are the highest. The totality of the Southeast will need
to be monitored for an increase in fire weather concerns through
much of the upcoming week.
Elsewhere, across the Southern Plains the very dry low-level airmass
will remain firmly entrenched beneath northwest flow aloft. The
result will be minimum afternoon relative humidity percentages
falling into the teens with maximum surface winds between 10-15 mph
(and locally higher gusts). This will support a continued elevated
risk of fire weather conditions.
..Marsh.. 12/28/2025
.PREV DISCUSSION... /ISSUED 0142 AM CST Sun Dec 28 2025/
...Synopsis...
A mid-level trough will impinge on the East Coast tomorrow (Monday),
resulting in northwesterly upper flow overspreading the Plains
states through the Day 2 period. Northwesterly flow will also
prevail at the surface over the Plains as surface high pressure
settles over the region. Sustained surface north-northwesterly winds
should peak around 15 mph by afternoon, amid 40 F surface
temperatures and 15-25 percent RH. Given drying fuels, the
aforementioned meteorological conditions should support low-end
Elevated conditions. The best chance for these conditions will be
across the eastern Texas Panhandle into northwest Texas and western
Oklahoma, where Elevated highlights have been introduced.
...Please see www.spc.noaa.gov/fire for graphic product...
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