Alert archive / Illinois / Tornado Warnings in 2026

Tornado Warning 137, NWS Lincoln, IL

August 9, 2026Knox County, Peoria County, Illinois

NWS Lincoln, IL issued this tornado warning at Aug 9, 2026, 9:57 PM CDT for Knox County, Peoria County, Illinois. It was in force for 48 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 9, 2026, 9:57 PM CDT (02:57 UTC)
Expired
Aug 9, 2026, 10:45 PM CDT
In force
48 min
Issued by
NWS Lincoln, IL
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Knox County, IL, Peoria County, IL

The radar

The Quad Cities radar (KDVN), 94 km from the middle of the area, began a volume at 02:59 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this tornado warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 9, 8:43 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 3.0 hours before the alert went out and 92 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2026-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3740 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2026-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
3740 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
810 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
322 m²/s²
Significant tornado parameter
4.3
Supercell composite
24.8

Open this sounding in Storm Lab

The text

As transmitted.

036 
WFUS53 KILX 100257
TORILX
ILC095-143-100345-
/O.NEW.KILX.TO.W.0137.260810T0257Z-260810T0345Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Lincoln IL
957 PM CDT Sun Aug 9 2026

The National Weather Service in Lincoln has issued a

* Tornado Warning for...
  East central Knox County in west central Illinois...
  Northwestern Peoria County in central Illinois...

* Until 1045 PM CDT.

* At 957 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Maquon, or 11 miles southeast of Galesburg, moving
  east at 25 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Williamsfield around 1010 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Laura and Brimfield.

This includes Interstate 74 between mile markers 57 and 74.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4083 8985 4083 9021 4089 9024 4098 8990
      4097 8989
TIME...MOT...LOC 0257Z 261DEG 23KT 4087 9019 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

25
3 follow-up statements
546 
WWUS53 KILX 100309
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
1009 PM CDT Sun Aug 9 2026

ILC095-143-100345-
/O.CON.KILX.TO.W.0137.000000T0000Z-260810T0345Z/
Knox-Peoria-
1009 PM CDT Sun Aug 9 2026

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1045 PM CDT FOR EAST
CENTRAL KNOX AND NORTHWESTERN PEORIA COUNTIES...

At 1009 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Williamsfield, or 15 miles east of Galesburg, moving
east at 25 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This dangerous storm will be near...
  Williamsfield around 1015 PM CDT.
  Laura around 1025 PM CDT.
  Brimfield around 1030 PM CDT.

This includes Interstate 74 between mile markers 59 and 74.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4083 8985 4083 9015 4091 9015 4098 8990
      4097 8989
TIME...MOT...LOC 0309Z 264DEG 22KT 4087 9010 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

25
043 
WWUS53 KILX 100324
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
1024 PM CDT Sun Aug 9 2026

ILC095-143-100345-
/O.CON.KILX.TO.W.0137.000000T0000Z-260810T0345Z/
Knox-Peoria-
1024 PM CDT Sun Aug 9 2026

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1045 PM CDT FOR EAST
CENTRAL KNOX AND NORTHWESTERN PEORIA COUNTIES...

At 1024 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Yates City, or 19 miles southwest of Toulon, moving
east at 20 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This dangerous storm will be near...
  Brimfield around 1035 PM CDT.

This includes Interstate 74 between mile markers 65 and 74.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4083 8985 4083 9006 4089 9005 4091 8987
TIME...MOT...LOC 0324Z 259DEG 16KT 4085 9003 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

25
160 
WWUS53 KILX 100334
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
1034 PM CDT Sun Aug 9 2026

ILC095-100343-
/O.CAN.KILX.TO.W.0137.000000T0000Z-260810T0345Z/
Knox-
1034 PM CDT Sun Aug 9 2026

...THE TORNADO WARNING FOR EAST CENTRAL KNOX COUNTY IS CANCELLED...

The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 400 AM CDT for
central and west central Illinois.

&&

LAT...LON 4083 8985 4083 8998 4090 8999 4091 8987
TIME...MOT...LOC 0333Z 261DEG 22KT 4086 8996 

$$

ILC143-100345-
/O.CON.KILX.TO.W.0137.000000T0000Z-260810T0345Z/
Peoria-
1034 PM CDT Sun Aug 9 2026

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1045 PM CDT FOR
NORTHWESTERN PEORIA COUNTY...

At 1033 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Brimfield, or 17 miles south of Toulon, moving east
at 25 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This dangerous storm will be near...
  Brimfield around 1040 PM CDT.

This includes Interstate 74 between mile markers 69 and 74.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4083 8985 4083 8998 4090 8999 4091 8987
TIME...MOT...LOC 0333Z 261DEG 22KT 4086 8996 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

25

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Lincoln, IL wrote its last area forecast discussion before this tornado warning went out at Aug 9, 8:30 PM CDT, 1 hour 27 minutes earlier. Its key messages:

  • Dangerous heat continues through Wednesday, with peak heat index values between 100 and 109 degrees daily. A Heat Advisory remains in effect through Monday along and south of a Canton to Casey line. Additional headlines may eventually be needed Tuesday and Wednesday.
  • Severe thunderstorms and heavy rainfall are possible overnight and again Monday night into Tuesday. The greatest risks with these storms will be damaging winds and localized flooding.
Area forecast discussion, Aug 9, 8:30 PM CDT, 1 hour 27 minutes before
Area Forecast Discussion
National Weather Service Lincoln IL
830 PM CDT Sun Aug 9 2026

.KEY MESSAGES...

- Dangerous heat continues through Wednesday, with peak heat
  index values between 100 and 109 degrees daily. A Heat
  Advisory remains in effect through Monday along and south of a
  Canton to Casey line. Additional headlines may eventually be
  needed Tuesday and Wednesday.

- Severe thunderstorms and heavy rainfall are possible
  overnight and again Monday night into Tuesday. The greatest
  risks with these storms will be damaging winds and localized
  flooding.

&&

.UPDATE...
Issued at 829 PM CDT Sun Aug 9 2026

A warm front was laid out west-to east near the I-80 corridor
this evening. Scattered storms have recently developed in the
vicinity of the front, as a 40 kt southwest LLJ has developed
to our southwest, converging into northwest IL currently. CAMs
show pretty good agreement of increasing storm coverage and
intensity over the next several hours, mainly north of the I-74
corridor. Environment is highly unstable with MLCAPEs near 4000
J/kg, and deep layer shear is as high as 40 kt just to our
north. This suggests supercells and multicell clusters, capable
of frequent/vivid cloud to ground lightning, high rain rates up
to 2"/hr, and isolated large hail and damaging wind gusts with
the strongest updrafts. Storms should propagate to the east-
southeast with time, eventually bringing the storm risk as far
southeast as the Champaign/Vermilion counties later tonight.

&&

.DISCUSSION...
Issued at 107 PM CDT Sun Aug 9 2026

Synoptic Overview...
The synoptic pattern remains dominated by a robust 595 dam
upper-level ridge centered over the Four Corners, maintaining
persistent northwesterly flow across the Great Lakes. Central
Illinois resides on the periphery of this feature, effectively
placing the region within the Ring of Fire near a quasi-
stationary baroclinic zone. This configuration ensures hot,
humid conditions and a challenging convective forecast, as
models continue to struggle with the precise timing and
evolution of successive nocturnal mesoscale convective systems
(MCS).

Short-Term Convective Potential...
Regional radar imagery highlights an MCV from earlier upstream
convection traversing southern Wisconsin, which is driving
convective redevelopment over the Chicago metro area. Locally,
capping (MLCIN > 100 J/kg) continues to suppress activity,
though an outflow boundary currently moving across the
Mississippi River north of Quincy remains a focal point for
potential cap erosion this afternoon. If deep convection manages
to initiate, effective shear profiles of 25-30 kt (per the
latest RAP) are marginally sufficient for storm organization.
Consequently, thunderstorm probabilities remain low (around 20%)
north of I-72 through the early evening, but if storms do
develop they could be strong.

Overnight, the low-level jet (LLJ) is forecast to intensify,
focusing moisture convergence along the instability gradient to
our north. While the consensus of CAMs tracks the primary MCS
activity across northern Illinois into Indiana, the orientation
of Corfidi vectors from the northeast warrants caution. Should
upstream development align favorably, there remains potential
for propagation into central Illinois. Primary concerns with any
nocturnal development would be locally heavy rain due to
backbuilding and a damaging wind threat; trends will be
monitored closely through the overnight hours.

Heat and Instability: Monday - Wednesday...
A persistent 850mb thermal ridge will dominate the Great Plains
and Upper Midwest regions through mid-week, pushing
temperatures into the 90s across western and southern counties
of central Illinois. Sustained dew points in the mid-70s will
result in peak heat indices ranging from 100 to 109 degrees
daily. A Heat Advisory remains in effect for areas south of a
Canton to Casey line for Monday. While additional headlines may
be required Tuesday and Wednesday, uncertainty regarding the
extent of convective debris and outflow boundaries currently
precludes additional product issuance.

The convective pattern remains highly repetitive for the first
half of the week. Monday evening features an environment with
very strong instability, with GFS-progged MLCAPE values
approaching 4000 J/kg, supported by 25-35 kt of deep-layer
shear. While the primary axis of moisture convergence will shift
slightly south, Corfidi vectors again favor a southward
propagation path into central Illinois. Similar conditions will
be in place Tuesday and Tuesday night. Despite the persistent
PoPs, it is important to emphasize that numerous dry hours will
persist between convective waves.

Extended Outlook: Thursday - Weekend...
By the latter half of the week, western CONUS ridging will
amplify, fostering deeper downstream troughing over the Great
Lakes. This shift will place Central Illinois on the cooler side
of the baroclinic zone, leading to a transition toward near- to
slightly-below-normal temperatures. While the airmass will
moderate, the LLJ will continue to provide sufficient forcing to
maintain daily chances for showers and thunderstorms,
particularly during the evening and overnight periods.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 609 PM CDT Sun Aug 9 2026

Timing and placement of convective development tonight on the
nose of the low-level jet is still uncertain, but most likely
near to northeast of the I-74 corridor. Maintained PROB30 TSRA
mention at KPIA-KBMI-KCMI tonight. Beyond this, there is a low
chance of scattered TSRA Monday morning, but confidence is too
low to include a mention at this time. Away from storms, VFR
will dominate. South winds around 10 kt tonight will veer SW by
late morning, with occasional gusts around 20 kt through
afternoon.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from noon to 7 PM CDT Monday for ILZ036-040-041-
047>052-061>063-066>068-071>073.

&&

KEY MESSAGES...Deubelbeiss
UPDATE...25
DISCUSSION...Deubelbeiss
AVIATION...25
Hazardous weather outlook, Aug 9, 2:42 PM CDT, 7 hours 15 minutes before
Hazardous Weather Outlook
National Weather Service Lincoln IL
242 PM CDT Sun Aug 9 2026

ILZ027>031-036>038-040>057-061>063-066>068-071>073-101945-
Knox-Stark-Peoria-Marshall-Woodford-Fulton-Tazewell-McLean-Schuyler-
Mason-Logan-De Witt-Piatt-Champaign-Vermilion-Cass-Menard-Scott-
Morgan-Sangamon-Christian-Macon-Moultrie-Douglas-Coles-Edgar-Shelby-
Cumberland-Clark-Effingham-Jasper-Crawford-Clay-Richland-Lawrence-
242 PM CDT Sun Aug 9 2026

This Hazardous Weather Outlook is for central Illinois, east
central Illinois, southeast Illinois and west central Illinois.

.DAY ONE...Tonight.

Severe thunderstorms and heavy rain are possible this evening through
the overnight hours. The higher threat will be focused near and
north of the Interstate 74 corridor. Damaging wind gusts and locally
heavy rainfall are the primary hazards. A brief tornado cannot be
ruled out.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Heat indices of 100 to 109 degrees are expected Monday and Tuesday
afternoons, which could result in heat-related illness with extended
exposure.

Periods of thunderstorms are forecast this week. There is potential
for severe weather and heavy rain across parts of central Illinois
through midweek.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this evening and tonight.

Expected storm motion is toward the east around 30 to 40 mph.

Deubelbeiss

The office that day

Everything else NWS Lincoln, IL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 9, 10:22 PM CDTTornado WarningILXMarshall, Peoria, Stark27 min
Aug 9, 10:46 PM CDTTornado WarningILXPeoria24 min
Aug 10, 2:34 PM CDTHeat AdvisoryILXCass, Christian, Clark, Clay, Coles, Crawford and 16 more29 hr

Nearby

Tornado Warnings in Illinois, 2026Every tornado warning in 2026Tornadoes in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.