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
Read more
MD 2281 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR FAR EASTERN MISSOURI...CENTRAL AND SOUTHERN ILLINOIS...AND WESTERN INDIANA
Mesoscale Discussion 2281
NWS Storm Prediction Center Norman OK
0118 PM CST Sun Dec 28 2025
Areas affected...Far eastern Missouri...central and southern
Illinois...and western Indiana
Concerning...Severe potential...Watch possible
Valid 281918Z - 282115Z
Probability of Watch Issuance...60 percent
SUMMARY...A band of storms is expected to form along the cold front
by mid afternoon in Illinois and spread eastward through late
evening into Indiana. Occasional wind damage and a couple of
tornadoes will be the main threats, and a watch is possible by
20-21z.
DISCUSSION...A surface cyclone is in the early stages of deepening
along a baroclinic zone across northern IL, downstream from an
amplifying midlevel trough and associated 100+ kt midlevel jet.
Within the warm sector of the cyclone, visible satellite imagery
shows some cloud breaks from MO into central IL, where surface
temperatures have warmed to 68+ F with dewpoints in the low 60s.
Surface-based CAPE has increased to 500-1000 J/kg as convective
inhibition weakens immediately ahead of the front. Shallow
convection is ongoing in the zone of ascent along the front, and the
threat for thunderstorms will increase through late afternoon as the
front interacts with the moist/weakly unstable boundary layer into
IL.
Strong deep-layer shear/long hodographs favor supercells. Still,
relatively weak buoyancy, linear forcing for ascent and fairly fast
frontal movement favor a more linear storm mode tied closely to the
frontal circulation. Thus, a mixed convective mode is probable,
with damaging gusts the main threat given roughly 50 kt flow in the
lowest 1-2 km above ground level. A couple of tornadoes may also
occur with any sustained supercells and/or embedded circulations
within line segments. A watch may need to be considered by 20-21z.
..Thompson/Gleason.. 12/28/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...IWX...IND...PAH...LOT...ILX...LSX...
LAT...LON 38998743 37448896 37519006 38929046 39679034 40678945
41028902 41118844 41258684 41068649 40188648 38998743
MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
Read more
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
Read more
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.
Read more
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.
Read more
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.
Read more
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...
Read more
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...
Read more
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...
Read more
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
Read more
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
Read more
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
Read more
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
Read more
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
Read more
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
Read more
MD 2279 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHEAST ILLINOIS AND NORTHWEST INDIANA
Mesoscale Discussion 2279
NWS Storm Prediction Center Norman OK
1044 AM CST Sun Dec 28 2025
Areas affected...Northeast Illinois and northwest Indiana
Concerning...Severe potential...Watch unlikely
Valid 281644Z - 281845Z
Probability of Watch Issuance...20 percent
SUMMARY...The threat for isolated hail (near 1 inch diameter) and
wind damage will persist through about 19z across northeast Illinois
into northwest Indiana. A watch appears unlikely.
DISCUSSION...A slightly elevated storm cluster with some supercell
characteristics, and a history of 1 inch hail and some wind damage,
continues to move east-northeastward at 50-55 kt across southern
Livingston and northern Ford Cos. IL. This storm cluster is
tracking near the surface warm front, and appears to be associated
with a subtle/embedded speed max approaching central/northern IL.
Modified short-term forecast soundings suggest the updrafts are
rooted slightly above the surface near the warm front with surface
temperatures in the low 60s, while somewhat larger surface-based
CAPE is confined to areas a bit farther south with temperatures in
the mid 60s. Long hodographs/strong vertical shear will continue to
support organized/supercell structures before the storms outpace the
somewhat greater buoyancy in IL, but the overall hail/wind threat
should be limited by rather poor low-midlevel lapse rates. As such,
a watch remains unlikely in the short term.
..Thompson/Gleason.. 12/28/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...IWX...LOT...
LAT...LON 40928665 40768790 40788812 41018835 41188827 41478784
41598736 41758682 41688642 41228631 40928665
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
Read more
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...
Read more
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...
Read more
