Tornadoes · United States · Illinois · 2026

Unrated tornado, Argyle Lake Sp, Illinois, June 11, 2026

This Unrated tornado ran 0.1 miles across McDonough County on June 11, 2026, touching down at 4:54 PM CDT. It killed nobody.

Preliminary. This is NWS DVN's damage survey, filed in the Damage Assessment Toolkit. The rating, the path and the casualties are the survey's and can change while it is revised. The Storm Prediction Center compiles the official record of 2026 from these surveys and publishes it in the spring of 2027; this page moves to that tornado's permanent address when it does.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. EF065 to 85 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. EF186 to 110 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. EF2111 to 135 mph

    Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

  4. EF3136 to 165 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. EF4166 to 200 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. EF5over 200 mph

    Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

  7. Unratedthis tornado

    The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The survey

Rating, as surveyed
Unrated, preliminary
Date
June 11, 2026
Touchdown
4:54 PM CDT (21:54 UTC)
Lifted
4:55 PM CDT (21:55 UTC)
On the ground
1 minutes
Path length
0.1 miles (0.1 km)
Path width
0 yards (0 m)
Deaths
0
Injuries
0
County
McDonough County
Touchdown point
40.487, -90.738
Lift-off point
40.487, -90.736
Surveyed by
NWS DVN
Survey last edited
June 12, 2026
Record number
None yet. SPC numbers 2026 in the spring of 2027.

What the survey found

Chaser video of short lived condensation funnel on the ground. No known damage, rated as an EFU.

Written by NWS DVN in the NWS Damage Assessment Toolkit. A survey is revised as better evidence arrives.

What the Weather Service recorded

Following the storm filled day on June 10th, additional storms developed June 11th, in the morning and again during the afternoon and evening hours with heavy rain and sporadic severe wind. Four brief tornadoes also were reported that did not cause any known damage and were each rated as an EF-U.

Chaser video of short lived condensation funnel on the ground. No known damage, thus it was rated as an EFU.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

The forecast that day

The Storm Prediction Center had this point in a Moderate Risk, with a 0.15 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:53 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

What forecasters said that day

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

NWS Quad Cities, IA wrote its last area forecast discussion before the tornado touched down at Jun 11, 2:32 PM CDT, 2 hours 22 minutes earlier. Its key messages:

  • The threat for fast-moving, severe storms this continues this afternoon. A tornado watch is in effect across much of the area until 9PM.
  • Heavy rain and flooding is also a threat for those areas that saw the heaviest rain earlier today. A Flood Watch is in effect until 7PM.
  • Cooler and drier weather will settle in Friday, but a chance for storms returns Saturday. A few storms could be strong to severe.
Area forecast discussion, Jun 11, 2:32 PM CDT, 2 hours 22 minutes before
Area Forecast Discussion
National Weather Service Quad Cities IA IL
232 PM CDT Thu Jun 11 2026

.KEY MESSAGES...

- The threat for fast-moving, severe storms this continues this
  afternoon. A tornado watch is in effect across much of the
  area until 9PM.

- Heavy rain and flooding is also a threat for those areas that
  saw the heaviest rain earlier today. A Flood Watch is in
  effect until 7PM.

- Cooler and drier weather will settle in Friday, but a chance
  for storms returns Saturday. A few storms could be strong to
  severe.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 139 PM CDT Thu Jun 11 2026

Severe thunderstorm likelihood continues for this afternoon but
some muddiness exists in the forecast details. The imprint on the
atmosphere from the morning MCS is markedly present with stable
low-level air signatures on radar and satellite, and this extends
across much of our area. Offsetting this to some degree is the
1000 mb low pressure near Des Moines tracking northeast, resulting
in some synoptic scale air mass recovery from the south. While
southeast winds are gusting across eastern Iowa now, the amount of
recovery in that is still limited due to lingering widespread
cloud cover. The post MCS air mass is looking more likely to be
enough to prevent a full recovery to northwest portions of the
CWA, at least of a notable tornado threat and significant severe
wind threat. It may even prevent it for many locations north of
I-80 as well, but synoptically there is still strong forcing for
ascent spreading over the area so not able to say that for
certain.

In summary, the area we are particularly concerned for surface-
based supercell/multicells capable of longer-lived mesocyclones
is along and east of the Mississippi River and along and south of
I-80 during the mid to late afternoon. Given more oblique shear
orientation with respect to the incoming cold front, and just how
cold frontal convection tends to evolve, it might not take long
(1-3 hours after initiation) for developing storms across the CWA
to become more clusters or segments, with a good bet of severe
winds in any that do, some significant in any mature bowing
segments (75+ mph).

Storms should be east of the area this evening as a cold front
moves through. This cold front will bring northwest winds in
its wake. Forecast soundings have trended down a bit, but could
still see gusts in excess of 35 mph for a couple of hours after
the front passes through. These winds will taper off overnight
and become more westerly, and temperatures will fall into the
mid 50s.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 139 PM CDT Thu Jun 11 2026

Friday through Saturday...On Friday, a brief area of high
pressure will build in, leading to mostly sunny skies. This will
exit eastward Friday night, and southerly return flow will
develop. By Saturday afternoon forecast soundings show 1000 to
2000 J/kg, with ample deep layer speed shear. A weak boundary
will be the focus for scattered thunderstorms, and a few could
produce severe weather. Right now large hail looks like the
primary threat.

Sunday through Thursday...Ensemble guidance shows lower height
anomalies spreading across the central US next week, which
supports cooler temperatures. A few weak disturbances embedded
in northwest flow will bring small chances for showers and
thunderstorms, but overall the first half of next week appears
mostly dry.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 1235 AM CDT Thu Jun 11 2026

Main concern through 00Z this evening is scattered
thunderstorms. A few storms could produce damaging wind and
hail, but given the lower predictability did remove hail from
the TAFs.
A cold front will follow once storms exit the region this
evening, bringing VFR conditions, and a brief period of gusty
northwest winds. These winds will decrease later this evening
and overnight.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Flood Watch until 7 PM CDT this evening for IAZ040>042-051>054-
     063>068-076>078-087>089-098-099.
IL...Flood Watch until 7 PM CDT this evening for ILZ001-002-007-009-
     015>018-024>026-034-035.
MO...Flood Watch until 7 PM CDT this evening for MOZ009-010.

&&

SHORT TERM...NWS
LONG TERM...NWS
AVIATION...NWS
Hazardous weather outlook, Jun 11, 1:14 PM CDT, 3 hours 40 minutes before
Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
114 PM CDT Thu Jun 11 2026

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-121815-
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson-
Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll-
Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson-
Warren-Hancock-McDonough-Scotland-Clark-
114 PM CDT Thu Jun 11 2026

This Hazardous Weather Outlook is for portions of north central
Illinois...northwest Illinois...west central Illinois...east
central Iowa...northeast Iowa...southeast Iowa and northeast
Missouri.

.DAY ONE...THIS AFTERNOON AND TONIGHT

Another round of storms capable of producing severe weather will
develop this afternoon and evening. The main threat area is east
of the Mississippi River.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

Thunderstorms are expected Saturday afternoon and evening across
the area, some of which may be severe. The Storm Prediction Center
has a slight, level 2 out of 5, risk for parts of the area.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be needed today.

NWS

In the hours before

Local storm report, Jun 11, 1:28 PM CDT, 3 hours 26 minutes before
Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
128 PM CDT Thu Jun 11 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0845 AM     Rain             1 WNW Bettendorf        41.57N 90.50W
06/11/2026  M2.00 Inch       Scott              IA   Trained Spotter

            24-hour rainfall accumulation.

&&

CMD
Local storm report, Jun 11, 1:33 PM CDT, 3 hours 21 minutes before
Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
133 PM CDT Thu Jun 11 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1206 PM     Rain             2 NW North Liberty      41.76N 91.62W
06/11/2026  M0.78 Inch       Johnson            IA   Trained Spotter

            Todays AM rain total.

1139 AM     Rain             2 SW Yarmouth           41.01N 91.35W
06/11/2026  M1.00 Inch       Des Moines         IA   Public

            Rainfall total from 945-1130AM.

0941 AM     Rain             1 N Ely                 41.89N 91.59W
06/11/2026  M1.00 Inch       Linn               IA   Public

            Todays AM rain total.

0818 AM     Rain             Carthage                40.41N 91.13W
06/11/2026  M3.20 Inch       Hancock            IL   Trained Spotter

            Rainfall total from Wednesday and overnight.

0702 AM     Rain             Le Claire               41.60N 90.36W
06/11/2026  M1.05 Inch       Scott              IA   Trained Spotter

            24 hour rainfall.

0644 AM     Rain             3 E Garden Plain        41.81N 90.08W
06/11/2026  M1.20 Inch       Whiteside          IL   Trained Spotter

            Wednesday and overnight rainfall totals.

0630 AM     Rain             2 NE Colusa             40.59N 91.15W
06/11/2026  M1.47 Inch       Hancock            IL   Trained Spotter

            Rainfall total from last nights Severe
            Thunderstorm. Small live tree limbs down and
            heavy rainfall with gusty winds at times.

0132 PM     Rain             2 NNW Oakland Mills     40.97N 91.63W
06/11/2026  M1.20 Inch       Henry              IA   Trained Spotter

            Total from AM storms (830-1130AM).

&&
Special weather statement, Jun 11, 2:07 PM CDT, 2 hours 47 minutes before
Special Weather Statement
National Weather Service Quad Cities IA IL
207 PM CDT Thu Jun 11 2026

ILZ017-018-112115-
Bureau-Putnam-
Including the cities of Princeton and Hennepin
207 PM CDT Thu Jun 11 2026

...Strong Non-Thunderstorm Winds Through 4 PM...

Strong easterly wind gusts not associated with thunderstorms have
developed across part of the Interstate 80 corridor in Illinois
and portions of Bureau and Putnam counties. Spotters reported 55
to 65 MPH winds for 5 minutes in Princeton, Illinois just before 2
PM. These should persist through 3 to 4 PM. Expect temporary
difficult driving conditions for high profile vehicles.
Local storm report, Jun 11, 2:59 PM CDT, 1 hour 55 minutes before
Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
259 PM CDT Thu Jun 11 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0246 PM     Flash Flood      1 ESE Dubuque           42.50N 90.68W
06/11/2026                   Dubuque            IA   Emergency Mngr

            EM reported roads closed due to flooding.

&&

ALE
Local storm report, Jun 11, 4:24 PM CDT, 30 minutes before
Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
424 PM CDT Thu Jun 11 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0415 PM     Flash Flood      Dubuque                 42.50N 90.69W
06/11/2026                   Dubuque            IA   Public

            Report of flooded basements and running
            water over some neighborhood streets.

&&

The air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Davenport, (KDVN), 12:00Z

9.9 hours before the tornado, 128 km from the path. June 11, 2026.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2026-06-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 11 joules per kilogram, CIN -285, lifted condensation level 1008 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 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. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Davenport, at 12:00Z on 2026-06-11The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 54 square meters per square second, 0 to 6 km bulk shear 34 knots.19395878Sfc1 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. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
11 J/kg
Mixed-layer CIN
-285 J/kg
Surface CAPE
110 J/kg
Mixed-layer LCL
1008 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
-15 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
4.3 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 00:00Z

2.1 hours after it, 128 km from the path. June 12, 2026.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2026-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 9 joules per kilogram, CIN -418, lifted condensation level 893 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 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. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Davenport, at 00:00Z on 2026-06-12The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity -130 square meters per square second, 0 to 6 km bulk shear 60 knots.19395878Sfc1 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. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
9 J/kg
Mixed-layer CIN
-418 J/kg
Surface CAPE
344 J/kg
Mixed-layer LCL
893 m above ground
0-6 km bulk shear
60 kt
0-1 km bulk shear
26 kt
0-1 km storm-relative helicity
-130 m²/s²
0-3 km storm-relative helicity
-57 m²/s²
Significant tornado parameter
0.0
Supercell composite
-1.5
0-3 km lapse rate
3.9 K/km

Open this sounding in Storm Lab

The surface observations

Macomb Municipal (MQB), 8 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
00:00 UTC

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Lincoln radar (KILX), 124 km away, was scanning. The volume nearest the touchdown began at 21:52 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

This ground now

The live radar over the trackEvery 2026 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of June 11, 2026

65 more have been surveyed in the United States that day, so far.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 115:10 AM CDTEF1Cass, NE2.040
June 115:15 AM CDTEF0Cass, NE0.320
June 115:21 AM CDTEF1Cass, NE2.040
June 115:29 AM CDTEF1Fremont, IA1.530
June 115:33 AM CDTEF0Mills, IA1.720
June 115:58 AM CDTEF1Page, IA7.2100
June 116:08 AM CDTEF1Montgomery, IA5.70
June 116:08 AM CDTEF1Montgomery, IA5.70
June 116:11 AM CDTEF1Page, IA1.950
June 116:26 AM CDTEF2Adams, IA6.0200
June 114:05 PM CDTUnratedWashington, IA0.10
June 114:15 PM CDTUnratedHancock, IL0.20
June 114:56 PM CDTEF3Woodford, IL11.2930
June 115:17 PM CDTEF0Fulton, IL2.430
June 115:31 PM CDTUnratedFulton, IL0.220
June 115:31 PM CDTEF1LaSalle, IL4.4500
June 115:32 PM CDTEF3Livingston, IL11.96007
June 115:44 PM CDTEF1Livingston, IL22.8900
June 115:55 PM CDTUnratedLivingston, IL0.8250
June 115:58 PM CDTUnratedLaSalle, IL0.3100
June 116:08 PM CDTEF1Tazewell, IL12.9300
June 116:12 PM CDTEF1Kenosha, WI0.575
June 116:12 PM CDTUnratedBureau, IL1.40
June 117:01 PM CDTUnratedLee, IL6.050
June 117:06 PM CDTEF0McLean, IL11.0100
June 117:08 PM CDTUnratedKankakee, IL0.650
June 117:11 PM CDTEF0Lake, IN6.0150
June 117:20 PM CDTEF1Champaign, IL9.10
June 117:23 PM CDTEF1Ford, IL6.9100
June 117:25 PM CDTEF2Lake, IN6.57001
June 117:26 PM CDTEF1Champaign, IL3.0150
June 117:32 PM CDTEF0Lake, IN4.1150
June 117:36 PM CDTEF0Lake, IN12.7200
June 117:39 PM CDTEF1Vermilion, IL13.6100
June 117:44 PM CDTEF1Vermilion, IL8.1100
June 117:45 PM CDTEF0Iroquois, IL2.1250
June 117:48 PM CDTEF1Iroquois, IL1.250
June 117:48 PM CDTEF3Lake, IN22.5450
June 117:52 PM CDTEF1DuPage, IL3.0400
June 117:58 PM CDTEF0Newton, IN12.6200
June 118:58 PM EDTEF1Benton, IN12.3250
June 117:58 PM CDTEF0Newton, IN15.6200
June 118:59 PM EDTEF0Warren, IN10.575
June 118:04 PM CDTEF0DuPage, IL1.3150
June 118:15 PM CDTEF2Cook, IL8.33506
June 118:23 PM CDTUnratedPorter, IN0.210
June 119:29 PM EDTEF0Barry, MI4.650
June 119:31 PM EDTEF0Kent, MI4.270
June 119:31 PM EDTEF0Carroll, IN3.475
June 119:43 PM EDTEF0Carroll, IN0.325
June 119:46 PM EDTEF1Cass, IN0.8250
June 119:58 PM EDTEF1Cass, IN1.5100
June 1110:11 PM EDTEF1Marshall, IN0.7125
June 1110:11 PM EDTEF0Marshall, IN2.9125
June 1110:22 PM EDTEF1Wabash, IN4.702
June 1110:22 PM EDTEF1Marshall, IN3.4300
June 1110:33 PM EDTEF1Huntington, IN5.875
June 1110:39 PM EDTEF1Huntington, IN7.950
June 1110:42 PM EDTEF2Elkhart, IN6.11001
June 1110:44 PM EDTEF1Huntington, IN0.725

All 66 of them

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. A survey can be revised, so the rating, the path and the casualties can all still change.

Sources

NWS Damage Assessment Toolkit, the record the survey teams file from the damage, and NOAA Storm Prediction Center storm reports. Neither is the official database for 2026, which SPC publishes in the spring of 2027.