Tornadoes · United States · Illinois · 2023

EF0 tornado, Minooka to Peotone, Illinois, July 28, 2023

From Minooka to Peotone, this EF0 tornado ran 5.1 miles across Will County on July 28, 2023, touching down at 10:59 PM CDT and reaching 60 yards wide. It killed nobody.

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 mphthis tornado

    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. Unrated

    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 record

Rating
EF0
Date
July 28, 2023
Touchdown
10:59 PM CDT (03:59 UTC)
Lifted
11:05 PM CDT (04:05 UTC)
On the ground
6 minutes
Path length
5.1 miles (8.3 km)
Path width
60 yards (55 m)
Deaths
0
Injuries
0
County
Will County
Touchdown point
41.364, -88.173
Lift-off point
41.358, -88.075
Record number
2307282159-01

The damage survey

135 damage points were recorded along this path by NWS LOT, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 95 mph.

  • Significant loss of SW side of church roof. Wind appears to have gotten in under an arch resulting in uplift of a portion of the roof.
  • Concentrated area of tree damage. Twisted limbs. Little to no roof damage.
  • Limbs fell onto roof. No uplift noted. Lots of tree damage in this area.
  • Pictures relayed via email of some minor siding damage and trees down at this location

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

What the Weather Service recorded

July 28th saw two rounds of severe storms move across the Chicago metro, one during the predawn hours of the morning and another during the evening. The first round brought isolated instances of damaging wind to the area and the second featured damaging winds, severe hail, and 13 tornadoes across the WFO Chicago CWA: 11 in Illinois and 2 in Indiana. Additionally, temperatures in the 90s and high humidity resulted in oppressively hot conditions with afternoon heat indices as high as 105-115��F.

This tornado initially touched down near the Minooka Primary Center in Grundy County and tracked east, roughly along and just north of East Church Street. The most significant damage occurred at the Apostolic Church on Church Street where winds appeared to have lifted about one quarter of the south-facing portion of the roof above an open archway. This damage appeared to be consistent with high-end EF-0 winds. A concentrated corridor of tree damage was then noted between East Church Street and East Coady Drive. This tornado continued to the east-northeast, crossing into Will County just north of E Church St. before moving across the Lake Chaminwood Preserve and I-55 at Canal Road. Several large trees were uprooted at Crane Composites as the tornado crossed US Route 6. This tornado appeared to have lifted over the Des Plaines River east of Cavalea Dr.

This tornado touched down in a subdivision just east of Hare Rd in Kendall County and tracked east crossing Wildy Rd just prior to moving into western Will County. After crossing into Will County, the tornado produced a concentrated region of tree damage at a single homestead consistent with high-end EF-0 winds. The tornado then proceeded northeastward and intensified as it crossed the DuPage River at River Crossing Park, where numerous large trees were snapped and some structural damage to houses occurred consistent with winds near 95 mph. The tornado crossed I-55 just north of exit 251 and continued into the west side of Joliet to produce sporadic tree damage on the far north end of Joliet Junior College. It then moved across the Inwood Soccer Complex and lifted near McDonough Street and Joyce Road.

This tornado occurred entirely within the Midewin National Tallgrass Prairie in Wilmington. It dropped just north of where Boathouse FS Rd crosses Prairie Creek and traversed eastward across the Prairie, crossing IL Rt. 53 in the process. Numerous instances of tree damage were noted, including several oak trees whose tops had been snapped. The storm dissipated on the east side of the Prairie shortly before a second tornado dropped near the park's eastern periphery.

To the east of the tornado that lifted over Midewin National Tallgrass Prairie, a second tornado began near South Warner Bridge Road between Wilton Center and West Doyle Roads. Here, several trees were uprooted and numerous large limbs were downed. One tree fell onto a residence, resulting in roof damage. Shingle loss and damage to gutters, siding, fascia, and soffit were all consistent with high-end EF-0 winds near 85 mph. The tornado tracked nearly due east to the north of West Arsenal Road, causing intermittent minor damage to corn and trees. The tornado moved southeast and crossed West Arsenal Road just west of US Route 52. At this point, the tornado was likely less than 15 yards wide with winds around 60 mph. It continued eastward, crossing north of West Joliet Road near Laughton Preserve. The tornado appeared to have continued east a few more miles before dissipating in a field just west of US Route 45.

Drone footage and high resolution satellite data revealed that a tornado touched down near north of E 12000N Road just east of S Rathje Road south of Peotone and lifted in a field between S Drecksler Road and S Ridgeland Avenue. This tornado was on the ground for less than 2 minutes and was around 15 yards wide. The only damage noted was to crops, namely soybeans.

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

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

The county was under a severe thunderstorm watch, issued at 00:31 UTC and running to 05:44 UTC.

Issued (UTC)ExpiredProductOffice
00:31 UTC05:44 UTCSevere Thunderstorm WatchLOT
00:36 UTC05:25 UTCFlood WatchLOT
03:45 UTC04:30 UTCSevere Thunderstorm WarningLOT
03:55 UTC04:45 UTCSevere Thunderstorm WarningLOT
04:24 UTC04:45 UTCTornado WarningLOT

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The forecast that day

The Storm Prediction Center had this point in a Enhanced Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:53 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 Chicago, IL wrote its last area forecast discussion before the tornado touched down at Jul 28, 10:21 PM CDT, 38 minutes earlier.

Area forecast discussion, Jul 28, 10:21 PM CDT, 38 minutes before
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1021 PM CDT Fri Jul 28 2023

.MESOSCALE DISCUSSION...
Issued at 1021 PM CDT Fri Jul 28 2023

A few HP supercells have been festering about from Winnebago
County east into the northern Chicago suburbs. Recent radar trends
suggest these cells are becoming increasingly outflow dominant
with consolidating cold pools. Despite thunderstorms in and around
the Chicago metro area and earlier passage of a lake breeze, sfc
obs suggest that the air mass over the Chicago metro has recovered
and is strongly unstable. The cluster of storms over the northwest
suburbs appear likely to bow east-southeastward across the heart
of the Chicago metro with damaging winds.

Farther west into Ogle and Lee Counties, very impressive rear
inflow jet evident on our radar with 70-80 kt inbounds noted at
5000 ft agl on KLOT 88D. Recent radar trends show the convection
associated with this rear inflow jet seemingly catching up with
the outflow ahead of it. If this trend continues, it would suggest
a increasing damaging wind threat as these storms track eastward
across the I-80 corridor. Air mass ahead of this line is extremely
unstable, with sfc dewpoints still around 80F, lending credence
the >3500 j/kg shown on latest SPC mesoanalysis.

If the western convection continues to catch up with the outflow
and becomes more shear balanced, then we would need to watch for
potential QLCS tornadogenesis with this western line. Particularly
where the outflow from the NW burbs bow intersects this second
western bow nearly perpendicularly (near DeKalb/LaSalle line as of
1020 PM).

- Izzi

&&

.SHORT TERM...
Issued at 325 PM CDT Fri Jul 28 2023

Through Saturday...

Key Forecast Message:

* Thunderstorms expected to develop near a cold front late this
  afternoon this evening with an attendant severe and flash flood
  threat

Heat and oppressive humidity this afternoon with dew points of
75-80F are expected to provide the fuel for potentially explosive
thunderstorm development as a back-door lake breeze enhanced
front sags south through this evening. While confidence as of this
writing remains on the lower side regarding exact trends, no big
changes to the thinking regarding severe and flash flooding
threats.

The main severe threats are expected to be scattered damaging to
locally destructive winds and isolated to scattered instances of
large hail. In addition, a brief tornado or two may occur near
frontal/outflow boundary intersections, particularly with any
bowing structures. A Flood Watch may be issued for portions of the
area over the next few hours as convective evolution and focus
area becomes more clear. Preliminary thinking regarding watch
issuance is generally the I-80 and north counties, with the flash
flood vulnerable Chicago and Rockford metros potentially in the
cross-hairs.

...General Expected Convective Development Trends into Early Evening:

Exceptionally high dew points near to locally just above 80F are
pooling ahead of the back-door front, making its way into far
northeast Illinois this hour. Recent AMDAR soundings and the
visual look to the Cu field suggest a capping inversion remains in
place. The "clumpiest" Cu resides from inland of the lake breeze
across northern Illinois west-northwestward into Wisconsin and
north central IA, where SPC/RAP mesoanalysis is indicating that
the cap may be on its way to eroding. In addition to the capping,
we're lacking strong large scale forcing as of the 3pm hour, with
the most notable short- wave over the upper MS Valley and forecast
neutral mid- level height tendencies into the early evening.

May be signs of first CI over north central IA closer to the
aforementioned short-wave and near the cold front. Expectation
locally is for the back-door cold front to have CI once the cap
breaks given enhanced low-level convergence, plus upstream
convection to the west/northwest to fill in and gradually sag
south with the front this evening. Lake enhanced frontal
convection is forecast to develop in the 4-6pm timeframe, with
outflow gradually expanding the footprint southward, plus
additional convection northwest of the area likely to move in
toward and beyond 7pm for areas far inland of Lake Michigan.

...Severe Weather Threat:

Steep mid-level lapse rates and the swamp-like air mass are
contributing to very large MLCAPE up to 4000-4500 J/kg per recent
mesoanalysis. This is a "powder keg" sort of scenario in which
updrafts can quickly become severe thunderstorms in short order.
Effective deep layer bulk shear up to 30-40 kt with extreme
instability is sufficient for a severe threat, with storm mode
modulating residence time of variance threats. Downdraft CAPE
(DCAPE) pushing 1500 J/kg with steepening low-level lapse rates
suggests clusters becoming outflow dominant and potentially
congealing into bowing segments that would transition to more of a
damaging wind threat. Prior to that, the extreme instability and
steep mid-level lapse rates paired with supportive wind shear will
support both downburst damaging winds and large to potentially
very large damaging hail.

While damaging winds and hail are expected to be the primary
severe threats, we'd be remiss to discount any tornado threat
through a portion of this evening. 0-3km MLCAPE is forecast to
grow to up to 150 J/kg inland of the lake breeze front, so pooled
vorticity near the front introduce a concern for boundary
interaction related tornado-genesis. While low-level shear and
effective SRH are currently sub-marginal, effective SRH may
briefly increase to up to 200 m2/s2 early this evening. With the
sagging front, outflow boundaries, and increased low-level SRF in
play, we'll need to monitor for quick spin-ups, especially on
bowing segments interacting with aforementioned boundaries.

We're continuing to message the main window for the severe threat
to be from shortly after CI late this afternoon through about
midnight CDT tonight.

...Flash Flooding Threat:

Moisture pooling and advection streaming toward the sagging
frontal boundary of an already exceptionally moist air mass at the
low levels is expected to contribute to PWATs of up to 2-2.25" by
early this evening. With some localized areas in northwest Illinois
seeing over 2" of rain last night, and the ever-present vulnerability
of the Chicago and Rockford metros to flash flooding in these
areas, concern is certainly there for corridors of more than
localized flash flooding. Conceptually, this set-up checks some of
the key boxes for a frontal flash flood archetype, with potential
for back-building and training convection north of the sagging
cold front. The 12z HREF LPMM notably features some pockets of
3-5" of rain, with ensemble max hinting at upside potential being
5-7" amounts where repeated rounds of intense convection occur.
See WPC's recent MPD for additional thoughts on this. We're
looking at a decent chance of issuing a Flood Watch once
convective trends have shown their hand more conclusively.

Later Tonight-Saturday:

It's unclear how long more intense convection will persist
tonight, but generally showing higher PoPs stair-stepping south
along with thunder chances with time overnight. We'll have a large
reservoir of instability to work over, but sometimes reinforcing
outflows and force the effective surface front and front aloft
more quickly southward, so PoP trends will undoubtedly need
refining this evening.

On Saturday, most of if not the entire area is expected to be dry
with increasing sun from north to south. Minor exception to this
may be south of the Kankakee River where lingering instability
axis will take the longest to be shunted south. Model guidance has
trended downward with the magnitude of northerly winds over Lake
Michigan on Saturday and with it the potential for dangerous
swimming conditions at the beaches has also come down some. Can't
rule out the northerly winds being strong enough to necessitate a
Beach Hazards Statement for portions of the lakeshore, but at this
time, a moderate swim risk and possibly hazardous conditions will
be messaged. High temperatures on Saturday will be in the lower to
mid 80s for most of the area away from the lake, with isolated
upper 80s in far interior sections, while upper 70s to around 80F
are expected near the lake. Humidity levels will start out
uncomfortable but will moderate with time (especially north of
I-80) as drier air works in from the north during the afternoon.

Castro

&&

.LONG TERM...
Issued at 203 PM CDT Fri Jul 28 2023

Saturday night through Friday...

Key Messages:

* Quiet weather through the weekend and majority of the week

* Temperatures return to seasonal average

* Chances for storms return towards the end of the week

Discussion:

A reprieve from the hot and stormy weather pattern will come this
weekend into next week, with temperatures returning to seasonal
average. The ridge will slowly weaken and push west. Expect highs to
be in the low-to-mid 80s through midweek next week, with cooler
temperatures along the lakeshore (potentially in the mid-to-upper
70s). Temperatures could push into the upper 80s towards the end of
the week. Dew points will drop through the weekend, retreating into
the 50s, bringing an end to the oppressive humidity. Dry air in the
mid-levels will limit the potential for rain and storms through
midweek. Chances for storms will return to the forecast late next
week.

Carothers

&&

.AVIATION...
For the 00Z TAFs...

Aviation Forecast Concerns:

* Period of scattered strong to severe thunderstorms this evening.

* Generally north-northeast winds through the period, though
  variable wind directions in thunderstorms this evening.

* Low-confidence potential for a period MVFR ceilings late
  tonight/early Saturday.

Early evening surface analysis depicts low pressure over northeast
IA, with with a nearly stationary frontal boundary extending into
southwest WI then southeast across northern IL where the effective
boundary appears to combine with the lake breeze off of Lake
Michigan. AMDAR aircraft soundings through the mid-late afternoon
have depicted a slowly weakening capping inversion near the 850 mb
level across he Chicago metro area which has resulted in fairly
slow growth of convective clouds along the lake breeze boundary,
though most recent soundings indicate this is eroding more quickly
now and suspect taller updrafts from west of KDPA southeast to
near KMDW and KGYY will soon be capable of lightning production.
Weaker capping upstream across parts of IA/southwest WI were being
overcome by large scale ascent associated with an eastward moving
mid-level disturbance, and it appears that convection will develop
more rapidly into our forecast area over the next couple of hours
as this forcing works its way east. Very warm/humid air mass
across the area combined with increasing mid-level flow aloft will
likely support the potential for strong to severe storms across
the terminals this evening, with damaging wind gusts and large
hail the primary severe threats. Storms likely to be in the
vicinity of several TAF sites at 00Z, with better coverage
expected to develop by/after 01Z. High-res CAM guidance shows some
differences in details of evolution and ending later tonight,
though it appears that storms may linger in the vicinity to/a
little past midnight.

Weather quiets down late tonight, with north-northeast winds
persisting through the remainder of the period. Winds may gust
near 20 kts at times by Saturday afternoon, especially within a
few miles of Lake Michigan. Some potential exists for a period of
MVFR ceilings into Saturday morning, with conditions otherwise
VFR.

Ratzer

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Flood Watch...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
     ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ023-ILZ103-ILZ104-
     ILZ105-ILZ106-ILZ107-ILZ108 until 3 AM Saturday.

IN...Flood Watch...INZ001-INZ002-INZ010-INZ011 until 3 AM Saturday.

LM...None.
&&

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Hazardous weather outlook, Jul 28, 9:21 PM CDT, 1 hour 38 minutes before
Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
921 PM CDT Fri Jul 28 2023

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-300230-
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-
La Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-
Northern Cook-Central Cook-Southern Cook-Northern Will-
Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-Benton-
921 PM CDT Fri Jul 28 2023 /1021 PM EDT Fri Jul 28 2023/

This Hazardous Weather Outlook is for portions of North Central
Illinois...Northeast Illinois and Northwest Indiana.

.DAY ONE...Tonight.

Weather hazards expected...

  Significant Thunderstorm Risk...with an associated:
      Elevated Damaging Wind Risk...up to 70 mph.
      Limited Hail Risk...up to half dollar size.
      Limited Tornado Risk.
  Elevated Flooding Risk.

DISCUSSION...

Strong to severe thunderstorms will continue to overspread the
area late this evening into the early overnight hours, ahead of a
cold front which will move through the area late. Some of these
storms will be severe, capable of producing damaging to locally
destructive winds and large hail. A brief tornado or two can not
be ruled out. In addition, some of the storms will produce
torrential rainfall which could lead to flash flooding, especially
where several storms train across the same areas.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Saturday...
  Limited Thunderstorm Risk south of the Kankakee River.
  Moderate Swim Risk Lake Michigan Shore.
Thursday...
  Limited Thunderstorm Risk.

DISCUSSION...

Potentially hazardous swimming conditions may occur on Saturday
at Lake Michigan beaches.

.SPOTTER INFORMATION STATEMENT...

  Spotters may be needed through this evening.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the east-southeast around 30 mph.

LMZ740>745-300230-
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
921 PM CDT Fri Jul 28 2023

This Hazardous Weather Outlook is for portions of the Illinois
nearshore waters of Lake Michigan and the Indiana nearshore
waters of Lake Michigan.

.DAY ONE...Tonight.

Weather hazards expected...

  Significant Thunderstorm Risk...with an associated:
     Limited Hail Risk...up to half dollar size.
     Elevated Thunderstorm Wind Gust Risk...up to 60 knots.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Thursday...
  Limited Thunderstorm Risk.

Ratzer

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In the hours before

Local storm report, Jul 28, 10:10 PM CDT, 49 minutes before
Preliminary Local Storm Report
National Weather Service Chicago IL
1010 PM CDT Fri Jul 28 2023

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

0950 PM     Tstm Wnd Dmg     5 E Harmon              41.72N 89.46W
07/28/2023                   Lee                IL   Trained Spotter

            Tree on a house and a propane tank just S/SE
            of Polo at Sterling Rd and Route 26.

&&
Local storm report, Jul 28, 10:14 PM CDT, 45 minutes before
Preliminary Local Storm Report
National Weather Service Chicago IL
1014 PM CDT Fri Jul 28 2023

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

0950 PM     Tstm Wnd Gst     4 NNW Hampshire         42.15N 88.56W
07/28/2023  M59 MPH          Kane               IL   Public

            Personal Weather Station measured a 59mph
            gust.

&&
Local storm report, Jul 28, 10:21 PM CDT, 38 minutes before
Preliminary Local Storm Report
National Weather Service Chicago IL
1021 PM CDT Fri Jul 28 2023

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

1004 PM     Tstm Wnd Gst     4 S Compton             41.64N 89.09W
07/28/2023  M57 MPH          Lee                IL   Public

            Private weather station KILCOMPT5 recorded a
            57mph gust between Compton and Mendota.

&&
Local storm report, Jul 28, 10:22 PM CDT, 37 minutes before
Preliminary Local Storm Report
National Weather Service Chicago IL
1022 PM CDT Fri Jul 28 2023

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

1008 PM     Tstm Wnd Gst     1 N Amboy               41.73N 89.33W
07/28/2023  M53 MPH          Lee                IL   Public

            Private weather station KILAMBOY21 recorded
            53mph gust near Amboy.

&&
Local storm report, Jul 28, 10:24 PM CDT, 35 minutes before
Preliminary Local Storm Report
National Weather Service Chicago IL
1024 PM CDT Fri Jul 28 2023

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

1022 PM     Tstm Wnd Gst     5 SE Harmon             41.66N 89.50W
07/28/2023  M49 MPH          Lee                IL   Public

            Private weather station KILHARMO7 recorded
            49mph gust.

&&
Local storm report, Jul 28, 10:57 PM CDT, 2 minutes before
Preliminary Local Storm Report
National Weather Service Chicago IL
1057 PM CDT Fri Jul 28 2023

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

1024 PM     Non-Tstm Wnd Gst 2 NNW Marseilles        41.36N 88.72W
07/28/2023  M54 MPH          La Salle           IL   Public

            Private weather station KILMARSE11 recorded
            54mph gust.

&&

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.

Lincoln, IL (KILX), 00:00Z

4.0 hours before the tornado, 140 km from the path. July 29, 2023.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2023-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 3041 joules per kilogram, CIN -109, lifted condensation level 1642 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, Lincoln, IL at 00:00Z on 2023-07-29The 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 113 square meters per square second, 0 to 6 km bulk shear 24 knots.1939Sfc1 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
3041 J/kg
Mixed-layer CIN
-109 J/kg
Surface CAPE
5577 J/kg
Mixed-layer LCL
1642 m above ground
0-6 km bulk shear
24 kt
0-1 km bulk shear
18 kt
0-1 km storm-relative helicity
113 m²/s²
0-3 km storm-relative helicity
242 m²/s²
Significant tornado parameter
0.0
Supercell composite
16.2
0-3 km lapse rate
7.2 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 12:00Z

8.0 hours after it, 140 km from the path. July 29, 2023.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2023-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 105 joules per kilogram, CIN -536, lifted condensation level 1292 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, Lincoln, IL at 12:00Z on 2023-07-29The 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 64 square meters per square second, 0 to 6 km bulk shear 38 knots.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. 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
105 J/kg
Mixed-layer CIN
-536 J/kg
Surface CAPE
66 J/kg
Mixed-layer LCL
1292 m above ground
0-6 km bulk shear
38 kt
0-1 km bulk shear
17 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
3.3 K/km

Open this sounding in Storm Lab

The surface observations

Joliet (JOT), 18 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
02:15 UTC87.478.8220° 4 kt1010.8
02:35 UTC86.578.80° 0 kt1011.5
02:55 UTC8678.80° 0 kt1011.5
03:15 UTC85.3790° 0 kt1011.2
03:35 UTC85.379.30° 0 kt1011.9
03:55 UTC85.379.70° 0 kt1010.8
04:10 UTC8072.7320° 19 kt331015.2+RA

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

The radar

The Chicago radar (KLOT), 27 km away, was scanning. The volume nearest the touchdown began at 03:59 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.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
01:02 UTCHAIL 11 Sw Glen EllynDupage, ILReport from mPING: Quarter (1.00 in.).
03:16 UTCTSTM WND GST 584 W BataviaKane, ILPeak gust measured on personal weather station KILGENEV45.
03:24 UTCTSTM WND GST 542 Nnw MarseillesLa Salle, ILPrivate weather station KILMARSE11 recorded a 54mph gust.
03:24 UTCNON-TSTM WND GST 542 Nnw MarseillesLa Salle, ILPrivate weather station KILMARSE11 recorded 54mph gust.
03:25 UTCTSTM WND GST 702 W SomonaukDe Kalb, ILTrained spotter estimated 70 mph wind gusts just west of Somonauk.
03:32 UTCTORNADO3 S NewarkKendall, ILAn NWS Damage Survey confirmed that an EF-0 tornado with peak winds of 85 mph, a path of 8.8 miles, and a maximum width of 80 yards impacted Newark to Lisbon. This tornado damaged trees, roofing material, siding and seve
03:34 UTCTSTM WND GST 533 Nnw SheridanLa Salle, ILPeak gust measured on personal weather station KILLELAN10.
03:34 UTCTSTM WND GST 671 Nnw SandwichDe Kalb, ILPeak gust measured on personal weather station KILSANDW47.
03:34 UTCTSTM WND GST 671 Nnw SandwichDe Kalb, ILPrivate weather station KILSANDW47 recorded a 67mph gust.
03:36 UTCTSTM WND DMG1 E MillingtonKendall, ILTrees downed onto Crimmins Rd. Time estimated from radar.
03:37 UTCTSTM WND DMGMillbrookKendall, IL15-20 inch diameter tree snapped in Millbrook. Time estimated by radar.
03:38 UTCTSTM WND DMGPlanoKendall, ILSeveral large tree limbs downed in Plano. Part of fence also blown over. Time estimated from radar.
03:40 UTCTSTM WND DMG3 Ene NewarkKendall, ILPictures received of a barn with part of its roof blown off, damage to barn door, and a small storage tank knocked over. Time estimated from radar.
03:40 UTCTSTM WND DMGBig RockKane, ILLarge tree branches down on house. Picture via social media.
03:43 UTCTSTM WND DMG2 S WheatonDupage, ILMultiple trees downed in Wheaton. Time estimated from radar.
03:44 UTCTSTM WND DMG2 Sse YorkvilleKendall, ILLarge tree snapped at the base along with several large branches. Time estimated from radar.
03:45 UTCTSTM WND DMGLombardDupage, ILPhoto shared on social media showing large tree limbs downed in Lombard. Time estimated from radar.
03:45 UTCTSTM WND DMGPlattvilleKendall, ILMultiple trees down and several large branches down around Plattville. Pictures via social media.
03:47 UTCTSTM WND DMGNapervilleDupage, ILMany large branches up to 8 inches in diameter across central and eastern Naperville.
03:49 UTCTSTM WND DMGYorkvilleKendall, ILMultiple reports of large trees downed in Yorkville. Time estimated from radar.
03:50 UTCTSTM WND GST 802 Se PlattvilleKendall, ILMeasured on personal weather station. A nearby tree was uprooted.
03:51 UTCTORNADO2 Nnw MinookaKendall, ILAn NWS Damage Survey confirmed that an EF-1 tornado with peak winds of 95 mph, a path length of 7.6 miles, and a maximum width of 225 yards began on the far north side of Minooka and tracked northeastward through the sou
03:52 UTCTSTM WND DMG2 Ne YorkvilleKendall, ILUtility pole downed. Time estimated from radar.
03:53 UTCTSTM WND DMGMinookaGrundy, ILRoof partially torn off church in Minooka. Possible tornado damage.
03:54 UTCTSTM WND GST 521 Wnw MorrisGrundy, ILPeak gust measured on personal weather station KILMORRI78.
03:54 UTCTSTM WND GST 713 Nw VeronaGrundy, ILPrivate weather station KILVERON5 recorded 71mph gust.
03:55 UTCTSTM WND GST 623 Wnw MazonGrundy, ILPeak gust measured by mesonet station DVI02735 3 WNW Mazon.
03:56 UTCTSTM WND DMG4 S ChannahonWill, ILPhoto shared on social media showing part of a large tree downed onto a driveway. Time estimated from radar.
03:57 UTCTSTM WND DMGChannahonWill, ILMultiple reports of large trees downed in Channahon. Time estimated from radar.
03:57 UTCTSTM WND DMGShorewoodWill, ILMultiple reports of tree damage in Shorewood. Time estimated from radar.
03:59 UTCTSTM WND DMGHinsdaleDupage, ILPhoto shared on social media showing a large tree uprooted in Hinsdale. Time estimated from radar.
04:00 UTCTSTM WND GST 603 Wsw ChannahonGrundy, ILEstimated 60-70mph gust.
04:00 UTCTSTM WND GST 813 Ssw MinookaGrundy, ILMeasured on personal weather station.
04:01 UTCTORNADO3 Ssw ElwoodWill, ILAn NWS Damage Survey confirmed that an EF-0 tornado with peak winds of 85 mph, a path of 15.4 miles, and a maximum width of 60 yards impacted the Midewin Prairie to Wilton Center to near Peotone. This tornado downed seve
04:02 UTCTSTM WND DMG1 Ssw BataviaKane, ILMultiple reports of tree limbs downed in the Batavia and North Aurora area. Time estimated from radar.
04:02 UTCTSTM WND DMG2 W AuroraKane, ILTree downed near Aurora University. Time estimated from radar.
04:05 UTCTSTM WND DMG1 W BraidwoodWill, ILSeveral trees approximately 12 inches in diameter uprooted near the intersection of Main St. and Cook St. in Braidwood.
04:07 UTCTSTM WND DMG1 Ssw Lakewood ShoresWill, ILTrees were downed at multiple residences along the Kankakee River in and near Wilmington. Time estimated from radar.
04:10 UTCTSTM WND GST 522 Nne WilmingtonWill, ILMidewin RAWS peak gust.
04:10 UTCTSTM WND GST 82ManhattanWill, ILMeasured on personal weather station. A metal canopy at a nearby restaurant was blown away.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2023 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of July 28, 2023

16 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 285:46 PM CDTEF1Franklin, IA2.8120$60,000
July 285:55 PM CDTEF1Franklin, IA1.8125$70,000
July 289:16 PM CDTEF0Whiteside, IA to IL1.020
July 2810:25 PM CDTUnratedLaSalle, IL1.720
July 2810:28 PM CDTEF1Jefferson, WI1.390
July 2810:32 PM CDTEF0Kendall, IL0.820
July 2810:35 PM CDTEF0Kendall, IL4.980
July 2810:44 PM CDTEF0Kendall, IL1.020
July 2810:52 PM CDTEF1Kendall, IL7.6225
July 2810:53 PM CDTEF0Grundy, IL5.1250
July 2811:07 PM CDTEF0Will, IL7.160
July 2811:19 PM CDTEF0Kankakee, IL6.1350
July 2811:22 PM CDTUnratedWill, IL1.515
July 2811:30 PM CDTEF1Kankakee, IL5.590
July 2811:49 PM CDTEF0Newton, IN1.220
July 2811:54 PM CDTEF0Newton, IN0.630

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.