Illinois, 2020

Tornadoes and Hail in Illinois, August 10, 2020

August 10, 2020 · NWS LOT · 178 events in 17 counties and zones

During the late morning through the afternoon of Monday August 10th, a line of intense thunderstorms known as a derecho brought widespread severe wind damage across Iowa, northern Illinois and northern Indiana. In north central and northeast Illinois alone, the severe winds of 60 to 100 mph downed or damaged tens of thousands of trees, as well as caused severe damage to homes, businesses, and…

Where it happened

Every event with a place to put it. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

Open the live radar over this ground

The toll

Deaths
1
Injuries
10
Property damage
None recorded
Crop damage
None recorded
Events
178

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS LOT wrote it up.

During the late morning through the afternoon of Monday August 10th, a line of intense thunderstorms known as a derecho brought widespread severe wind damage across Iowa, northern Illinois and northern Indiana.

In north central and northeast Illinois alone, the severe winds of 60 to 100 mph downed or damaged tens of thousands of trees, as well as caused severe damage to homes, businesses, and infrastructure. There were 10 injuries reported in north central and northeast Illinois within the NWS Chicago/Romeoville County Warning Area (CWA). Local officials estimated that nearly one million customers lost power across northern Illinois at the height of the derecho and some people were without power for several days. Damage was estimated to be in the hundreds of millions of dollars in north central and northeast Illinois, with several billions of dollars in damages across the entire Corn Belt region including significant damage to crops and agriculture infrastructure. While much of the damage was due to straight line winds, there were also 14 tornadoes documented in north central and northeast Illinois.

The combination of high moisture, explosive instability and very strong atmospheric wind flow for mid-summer had developed quickly over the Corn Belt region on the morning of August 10th. This resulted in a progressive, well-organized complex of storms for hundreds of miles and at times traveling nearly 70 mph. After bringing extensive damage from extreme wind speeds in Iowa that morning, the damage transitioned across northern Illinois from widespread wind damage to narrow, brief and intense swaths associated with compact circulations within the thunderstorm line, some of which were associated with tornadoes.

What forecasters said that day

The local office's own words before the first event, 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 first event at Aug 10, 12:51 PM CST, 24 minutes earlier.

Area forecast discussion, Aug 10, 12:51 PM CST, 24 minutes before
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
151 PM CDT Mon Aug 10 2020

.SHORT TERM...
146 PM CDT

Through Tuesday night...

All eyes are on the incoming impressive convective complex surging
eastward towards the river early this afternoon. Given the number
of measured severe (and significant severe) wind gusts ongoing,
see no real reason that this won't continue well into and through
our CWA given the thermodynamic environment in place. Surface
temperatures have managed to claw their way into the upper 80s to
near 90 degrees with mid and even upper 70 degree dewpoints
expansive. This, combined with a rather steep mid-level lapse rate
plume overhead are supporting MUCAPE values now pushing 4000-5000
J/kg in an environment that is becoming increasingly uncapped.
Mid-level flow isn't off the charts, but seeing some 30-40 kt wind
retrievals around 700 mb and also analyzed 40 kts of effective
deep layer shear per recent SPC mesoanalysis. The complex-
orthogonal orientation is also favorable for convective sustenance
as this encourages renewed updraft development along the leading
edge of the cold pool.

Ultimately, the message really hasn't changed too much from
earlier this morning, but confidence in a rather widespread
significant wind event continues to march upwards here given
everything in place. Main corridor of concern seems to be roughly
the region bounded by I-90 and just south of I-80, but we'll note
that the entire region really is under a threat for severe weather
today, with the threats commensurately ramping up towards 1 PM
west of I-39, into the heart of the Chicago area around 3-5 PM,
and then out the southeast during the 5-8 PM time. We're also
seeing additional development taking place at the nose of the
warm advection wing and this may continue to push eastward near
and north of I-88. The threat here will be one of initial
thunderstorm training and associated localized flash flooding, as
well as a somewhat increased threat for large hail with any
transient supercellular structures.

The main threat is from straight line winds--again with a threat
for significant wind with gusts of 90 to even 100 mph not out of
the question. A secondary threat will be one of embedded QLCS
tornadoes/mesovortices. Low-level flow is not extremely strong,
but sufficient turning in the 0-2 km layer will support this
potential with signs of slightly backed surface winds there. If
nothing else, any mesovortices will be able to locally enhance
corridors of wind damage. Flash flooding exists as a tertiary
threat given the fast forward motion, but localized areas of
training will be possible, with some additional storms a threat
later this evening as the cold front finally moves through.

...Rip Current/Seiche/Meteotsunami Potential...
While not an ideal setup given the more west-to-east orientation,
we are growing a bit more concerned about a meteotsunami/seiche
threat given noted 2-4 mb/10 minute pressure rises at the head of
this incoming bow. These values are in a pretty narrow corridor,
but are getting into a moderate to significant range to force wind
stress on the lake. The main driving factor in this case will be
the winds, and should 60-70+ mph winds drive across the lake,
we'd expect at least modest water fluctuations developing well
after showers and storms have departed into the late-evening
hours. Given this, along with a threat for waves to build to 3-5
feet into NW Indiana beaches, we've elected to hoist a Beach
Hazards statement: 1 segment for the Cook County shore through
tonight where this a potential for rapid water fluctuations
associated with this wind surge, and a 2nd segment for our NW
Indiana county beaches (through early Tuesday afternoon). where
this threat will also exist, as well as a threat for waves
building to hazardous levels tonight into Tuesday. We'll keep an
eye on water level trends this evening for any short-fused
lakeshore flood advisory-type headlines.

High pressure builds in tomorrow with more quiescent conditions
expected. A lake breeze will likely keep our lakeside communities
several degrees cooler in the upper 70s with low to maybe mid 80s
more prevalent inland.

Carlaw

&&

.LONG TERM...
146 PM CDT

Wednesday through Monday...

Little has changed in the thinking during the long term portion of
the forecast.

A somewhat stagnant pattern looks to develop mid- week into the
upcoming weekend as mid-level ridging builds northward into Hudson
Bay. Meanwhile, abundant MCS activity across the central CONUS
over the next day or so may create a broad minimum in mid- level
heights across the Ohio Valley in otherwise zonal flow. The cold
front crossing the area this evening should ultimately wash out
well south of the CWA. With broad surface high pressure settling
over the Great Lakes region mid-week before drifting northeast
through the end of the week, a period of seasonable temps, lower
dew points, and generally east flow is expected Wednesday through
Saturday. Any precip potential during this time will hinge on the
evolution of convection within stronger westerlies across the
northern Great Plains. Some guidance hints at the potential for a
convectively- induced wave to shift into the Upper Mississippi
Valley late Thursday into Friday, ultimately amplifying the height
minimum across the Ohio Valley by the weekend. This would develop
a weak Rex block with the Hudson Bay ridge, placing a lot of
uncertainty in precip potential beginning late Thursday as any
slight changes in the possible stalled mid- level flow could mean
the difference between an extended dry period and a potential
upper low settling near the CWA.

Kluber

&&

.AVIATION...
For the 18Z TAFs...

Currently, a well-organized/derecho-producing MCS with measured
wind gusts in excess of 55 kt is sweeping across Iowa with a
forward motion of 55-60 kt. With ample instability ahead of the
line and "favorable" diurnal timing, the expectation is the line
will hold together and race through all terminals early this
afternoon. Currently, we have it timed out to reach RFD around
1930Z, DPA around 2000Z, ORD/MDW around 2030Z, and GYY around 2100Z
(though slight adjustments remain possible). Along the leading
edge of the line, wind gusts in excess of 55 kt are possible.
Once the line moves through, a wake low will lead to
north/northeast winds with gusts perhaps as high as 30 kt.

Winds will become light and variable at some point this evening
behind the line of storms and wake low (currently timing as such
around 00Z or so). Thereafter, the synoptic winds out of the west,
albeit light, should resume.

Finally, did offer some mention of a lake breeze toward the very
end of the TAF period at MDW/ORD.

Borchardt

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ103-ILZ104-ILZ105...6 PM Monday to
     7 AM Tuesday.

IN...Beach Hazards Statement...INZ001-INZ002...7 PM Monday to 1 PM
     Tuesday.

LM...None.
&&

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Hazardous weather outlook, Aug 10, 10:42 AM CST, 2 hours 33 minutes before
Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
1142 AM CDT Mon Aug 10 2020

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-111645-
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-
1142 AM CDT Mon Aug 10 2020 /1242 PM EDT Mon Aug 10 2020/

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

.DAY ONE...This Afternoon and Tonight.

Weather hazards expected...

  Significant Thunderstorm Risk...with an associated:
     Significant damaging wind risk...up to 80 mph.
     Limited Tornado risk.
     Limited hail risk...up to ping pong ball size.
  Limited Flooding Risk.
  Limited Excessive Heat Risk.

DISCUSSION...

A line of severe thunderstorms is expected to move through the
region this afternoon with a threat for widespread damaging wind
gusts roughly during the 1 to 7 pm timeframe. In addition, there
will be a threat for a tornado or two as well as instances of
large hail to the size of ping pong balls. Locally heavy rainfall
may also lead to isolated instances of flooding into this evening.

Ahead of the thunderstorms, warm and humid conditions will prevail
through early this afternoon with heat indices peaking in the 96
to 103 degree range.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Tuesday...
  Limited Thunderstorm Risk in the morning south.
Thursday through Sunday...
  Limited Thunderstorm Risk.

.SPOTTER INFORMATION STATEMENT...

  Spotters will likely be needed this afternoon.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the east-southeast at 50 to 60 mph.

LMZ740>745-111645-
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-
1142 AM CDT Mon Aug 10 2020

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...This Afternoon and Tonight.

Weather hazards expected...

  Significant Thunderstorm Risk...with an associated:
     Significant thunderstorm wind gust risk...up to 70 kts.
     Limited Waterspout Risk.
     Limited hail risk...up to ping pong ball size.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Thursday through Sunday...
  Limited Thunderstorm Risk.

Carlaw

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The radar

The Quad Cities radar (KDVN), 100 km away, was scanning. The volume nearest the first event began at 19:17 UTC.

Open the radar archive at this moment

Event by event

154 thunderstorm wind, 16 tornado, 7 hail, 1 funnel cloud. Local standard time, as filed.

Thunderstorm Wind, Ogle

When
August 10, 1:15 PM CST to 1:20 PM CST
Where
Ogle County, 0.69 mi NNW of Forreston to 0.89 mi NNE of Forreston
Measured
87 kt (100 mph) estimated gust
Injuries
5 direct, 0 indirect
Reported by
Newspaper
Coordinates
42.129, -89.587

Straight line winds gusting to 100 mph hit the town of Forreston producing widespread tree and power line damage. Tree and power line damage occurred across 48 blocks of the village and structural damage occurred across 13 blocks. Several mobile homes were damaged or destroyed in two mobile home parks and five people were injured. At least 50 people were displaced. Significant damage occurred to a large metal building near a gas station with associated debris blown toward the northeast. The gas station had its heating and cooling unit ripped off the roof, leaving a hole in the roof. A cinder block wall was blown out of the east side of a building causing minor damage to a parked semi truck. A garage partially collapsed from a fallen tree. Several other roofs suffered some damage from falling tree limbs. A car was damaged by a falling tree limb.

Thunderstorm Wind, Lee

When
August 10, 1:25 PM CST
Where
Lee County, 0.37 mi WNW of Harmon
Measured
70 kt (81 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.722, -89.556

Several tree limbs were blown down. Exterior siding of a house was peeled away.

Tornado, Winnebago

When
August 10, 1:37 PM CST to 1:38 PM CST
Where
Winnebago County, 2.11 mi S of Rckfrd Cottonwood Ar to 1.5 mi WSW of Rockford
Rating
EF0
Path length
1.58 mi
Path width
50 yd
Reported by
NWS Storm Survey
Coordinates
42.249, -89.133

A brief tornado with peak winds of 75 mph touched down near the intersection of Pierpont Avenue and Montague Road and continued northeast into the southwest side of Rockford. The tornado ended near the intersection of Ferguson and Loomis Streets. All of the damage was to trees along the tornado path.

Thunderstorm Wind, Ogle

When
August 10, 1:37 PM CST to 1:40 PM CST
Where
Ogle County, 2.28 mi W of Flagg Center to 1.05 mi NW of Rochelle
Measured
65 kt (75 mph) estimated gust
Reported by
Law Enforcement
Coordinates
41.930, -89.164

Tree and power line damage occurred across many areas in Ogle County, from Forreston to rural Rochelle.

Thunderstorm Wind, Lee

When
August 10, 1:39 PM CST
Where
Lee County, 3.59 mi SSW of Dixon
Measured
80 kt (92 mph) measured gust
Reported by
Public
Coordinates
41.780, -89.497

A private weather station measured a wind gust to 92 mph. Winds gusted above 50 mph for 20 to 30 minutes.

Thunderstorm Wind, Winnebago

When
August 10, 1:39 PM CST to 1:46 PM CST
Where
Winnebago County, 0.62 mi S of Rckfrd Cottonwood Ar to 2.03 mi S of Samuelson Corners
Measured
74 kt (85 mph) estimated gust
Reported by
Broadcast Media
Coordinates
42.271, -89.131

Widespread tree damage occurred in Rockford with trees snapped and uprooted and large tree limbs blown down. At least 150 utility poles were damaged along with power lines blown down. Hundreds of homes were damaged by falling tree limbs.

Thunderstorm Wind, Ogle

When
August 10, 1:40 PM CST
Where
Ogle County, 1.95 mi S of Kings
Measured
60 kt (69 mph) estimated gust
Reported by
Broadcast Media
Coordinates
41.972, -89.094

A large tree limb was blown down.

Thunderstorm Wind, La Salle

When
August 10, 1:40 PM CST to 1:41 PM CST
Where
La Salle County, 1.04 mi E of Cedar Pt
Measured
79 kt (91 mph) measured gust
Reported by
Trained Spotter
Coordinates
41.270, -89.110

A wind gust to 91 mph was measured. Roof damage was reported to homes; traffic signs were snapped; power lines were blown down and tree damage was reported.

Thunderstorm Wind, La Salle

When
August 10, 1:42 PM CST to 1:43 PM CST
Where
La Salle County, (Vys) Illinois Valley Regional Airport
Measured
61 kt (70 mph) measured gust
Reported by
Newspaper
Coordinates
41.350, -89.150

Wind gusts at the Illinois Valley Regional Airport reached 70 mph and then the power went out. A worker at the airport described winds as much higher than that after the power went off.

Thunderstorm Wind, La Salle

When
August 10, 1:42 PM CST to 1:44 PM CST
Where
La Salle County, 0.91 mi WNW of Peru to 0.93 mi ENE of La Salle
Measured
74 kt (85 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.333, -89.147

Trees, tree limbs and power lines were blown down in Peru and La Salle. Some roads were blocked by fallen trees.

Thunderstorm Wind, La Salle

When
August 10, 1:43 PM CST
Where
La Salle County, 1.31 mi E of (Vys) Illinois Valley Regional Airport
Measured
65 kt (75 mph) estimated gust
Injuries
1 direct, 0 indirect
Reported by
Broadcast Media
Coordinates
41.350, -89.125

A semi truck was blown over on Route 251, north of Peru. The driver was injured.

Thunderstorm Wind, La Salle

When
August 10, 1:43 PM CST to 1:44 PM CST
Where
La Salle County, 0.92 mi W of Oglesby to 0.81 mi WSW of Oglesby
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.299, -89.088

Two semi trucks were blown over west of Oglesby. One was blown over on the southbound exit from Interstate 39 and the second was blown over just north of the entrance to a warehouse on Mallick Road.

Thunderstorm Wind, La Salle

When
August 10, 1:44 PM CST to 1:45 PM CST
Where
La Salle County, 0.41 mi SSW of Oglesby to 1.03 mi ESE of Oglesby
Measured
74 kt (85 mph) estimated gust
Reported by
Newspaper
Coordinates
41.295, -89.074

Trees, tree limbs and power lines were blown down in Oglesby. A number of trees were uprooted in Memorial Park. Several roads were blocked by fallen trees. Most of the city lost power.

Thunderstorm Wind, La Salle

When
August 10, 1:45 PM CST to 1:46 PM CST
Where
La Salle County, Mendota
Measured
70 kt (81 mph) estimated gust
Reported by
NWS Employee
Coordinates
41.550, -89.120

Wind gusts were estimated to 80 mph. Several large trees were blown down. Wind gusts to severe limits were frequent for 30 minutes after they started.

Thunderstorm Wind, La Salle

When
August 10, 1:46 PM CST
Where
La Salle County, 2.03 mi NNE of Mendota
Measured
65 kt (75 mph) estimated gust
Reported by
Public
Coordinates
41.577, -89.105

A large tree was blown down and a tree limb was impaled into the side of a manufactured home. Windows were also blown out of this home.

Tornado, Winnebago

When
August 10, 1:47 PM CST to 1:59 PM CST
Where
Winnebago County, 1.4 mi SSE of Samuelson Corners to 1.9 mi SSW of Argyle
Rating
EF1
Path length
6.03 mi
Path width
300 yd
Continued into
Boone, Il (LOT)
Reported by
NWS Storm Survey
Coordinates
42.281, -89.022

A tornado with peak winds of 100 mph touched down near Guilford Road, east of Alpine Road and traveled approximately 6 miles northeast to Argyle Road where it crossed into Boone County. Numerous trees, power lines, utility poles and fences were blown down from where the tornado touched down through the Mulford Road and Springbrook Road area. Significant tree damage occurred in a localized area near Rock Valley College. Just northeast of Perryville Road, some utility poles were broken along with extensive tree damage and minor roof and siding damage occurred to some homes. Part of the roof was blown off of a Farm and Fleet building along East Riverside Boulevard, just west of Interstate 90. A home suffered siding and roof damage and metal wall panels were blown off a building, both along Paulson Road.

Thunderstorm Wind, La Salle

When
August 10, 1:47 PM CST to 1:48 PM CST
Where
La Salle County, 2.02 mi E of Oglesby to 2.36 mi S of Utica
Measured
70 kt (81 mph) estimated gust
Injuries
3 direct, 0 indirect
Reported by
Newspaper
Coordinates
41.296, -89.031

Trees were blown down in Matthiessen State Park. Three women were injured by falling trees. One woman was treated at the scene in the Dells Area. Two women were injured in the River Area. One suffered head, neck and shoulder injuries but was able to walk back to a parking area to get help. The second woman was pinned to the ground by a fallen tree and was extricated by first responders. She was taken to a local hospital.

Thunderstorm Wind, Ogle

When
August 10, 1:48 PM CST
Where
Ogle County, Creston
Measured
60 kt (69 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.930, -88.970

Large tree limbs were blown down.

Tornado, De Kalb

When
August 10, 1:50 PM CST to 1:57 PM CST
Where
De Kalb County, 0.32 mi SSE of Fairdale to 3.1 mi W of Colvin Park
Rating
EF0
Path length
6.28 mi
Path width
40 yd
Reported by
NWS Storm Survey
Coordinates
42.096, -88.927

A tornado with peak winds of 80 mph touched down just southeast of Fairdale and moved northeast until it ended in a field east of Myelle Road. Drone footage showed a narrow swath of corn flattened in a convergent pattern. A utility pole was snapped along Buck Road. Tree damage occurred at a vocational farm along Pearl Street, just north of Wolf Road and a plastic covering was ripped off a greenhouse. The path of this tornado was determined, in part, using high resolution satellite imagery.

Thunderstorm Wind, La Salle

When
August 10, 1:52 PM CST to 1:54 PM CST
Where
La Salle County, 0.83 mi SSE of Utica to 0.77 mi S of Utica Airpark Arpt
Measured
70 kt (81 mph) estimated gust
Reported by
Newspaper
Coordinates
41.319, -89.013

Trees were blown down in Starved Rock State Park, blocking roads and trails.

Thunderstorm Wind, De Kalb

When
August 10, 1:53 PM CST
Where
De Kalb County, 4.07 mi WNW of Shabbona
Measured
70 kt (81 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.795, -88.942

Wind gusts were estimated between 70 mph and 80 mph in Lee.

Hail, Winnebago

When
August 10, 1:53 PM CST to 1:54 PM CST
Where
Winnebago County, 2.65 mi ESE of Samuelson Corners
Measured
1 in hail
Reported by
Trained Spotter
Coordinates
42.290, -88.980

Thunderstorm Wind, De Kalb

When
August 10, 1:53 PM CST
Where
De Kalb County, 0.79 mi N of Kirkland
Measured
50 kt (58 mph) estimated gust
Reported by
Trained Spotter
Coordinates
42.091, -88.848

Power lines were blown down in Kirkland.

Thunderstorm Wind, De Kalb

When
August 10, 1:55 PM CST to 1:56 PM CST
Where
De Kalb County, 0.67 mi W of Shabbona to 0.2 mi ESE of Shabbona
Measured
55 kt (63 mph) estimated gust
Reported by
Broadcast Media
Coordinates
41.769, -88.883

Tree limbs and power lines were blown down in Shabbona.

Thunderstorm Wind, La Salle

When
August 10, 1:56 PM CST
Where
La Salle County, 0.89 mi NE of Utica
Measured
70 kt (81 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.341, -89.010

Damage to roofs and outside structures was reported in Utica.

Thunderstorm Wind, La Salle

When
August 10, 1:57 PM CST to 1:58 PM CST
Where
La Salle County, 0.37 mi SW of Leland to 0.65 mi ESE of Leland
Measured
55 kt (63 mph) estimated gust
Reported by
Broadcast Media
Coordinates
41.616, -88.804

Tree limbs and power lines were blown down in Leland.

Thunderstorm Wind, La Salle

When
August 10, 1:57 PM CST to 2:00 PM CST
Where
La Salle County, 0.86 mi WSW of Ottawa to 1.38 mi E of Ottawa
Measured
74 kt (85 mph) estimated gust
Reported by
Newspaper
Coordinates
41.347, -88.866

Trees, tree limbs and power lines were blown down in Ottawa. A shed was destroyed. Multiple signs in downtown Ottawa were blown down.

Thunderstorm Wind, De Kalb

When
August 10, 1:58 PM CST to 2:00 PM CST
Where
De Kalb County, 0.86 mi W of De Kalb to 0.4 mi W of De Kalb Muni Arpt
Measured
60 kt (69 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.930, -88.767

Multiple trees and power lines were blown down in De Kalb.

Tornado, Boone

When
August 10, 1:59 PM CST to 2:05 PM CST
Where
Boone County, 2.75 mi SW of Caledonia to 0.56 mi E of Caledonia
Rating
EF1
Path length
3.15 mi
Path width
300 yd
Reported by
NWS Storm Survey
Coordinates
42.344, -88.940

A tornado touched down in southeast Winnebago County and moved northeast crossing into Boone County along Argyle Road. This tornado produced mainly tree damage in Boone County including tree limbs blown down in Caledonia. The tornado ended on the east side of Caledonia, south of Route 173.

Tornado, La Salle

When
August 10, 1:59 PM CST to 2:00 PM CST
Where
La Salle County, 0.36 mi NE of Ottawa to 1.18 mi E of Ottawa
Rating
EF1
Path length
0.9 mi
Path width
150 yd
Reported by
NWS Storm Survey
Coordinates
41.353, -88.845

A tornado with peak winds of 100 mph touched down south of Marquette Street west of La Salle Street. The tornado impacted several businesses ripping off well anchored roofing material and snapping a utility pole at its base. The roof of a flooring business was blown off and hit a nearby building. It was here the tornado reached peak intensity. The tornado continued east ripping shingles off of roofs of buildings and houses and shredding trees. One tree was shredded badly near Canal Street and a large tree limb fell onto a new pickup truck causing significant damage. Fallen trees and tree limbs covered most areas along the path to the Fox River. The tornado is believed to have lifted in an inaccessible forested area east of the Fox River. Eye witnesses indicated the tornado may have had multiple vortices with clear rising and rotating motion of debris.

Thunderstorm Wind, De Kalb

When
August 10, 1:59 PM CST to 2:00 PM CST
Where
De Kalb County, 0.74 mi WSW of Hart to 0.2 mi SSE of Genoa
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
42.097, -88.714

Trees, tree limbs and power lines were blown down in Genoa. One tree fell onto a house causing damage.

Hail, Boone

When
August 10, 2:00 PM CST to 2:01 PM CST
Where
Boone County, 0.86 mi NW of Belvidere
Measured
1 in hail
Reported by
Trained Spotter
Coordinates
42.260, -88.860

Thunderstorm Wind, De Kalb

When
August 10, 2:00 PM CST to 2:02 PM CST
Where
De Kalb County, 0.6 mi WNW of Somonauk to 0.61 mi ENE of Somonauk
Measured
78 kt (90 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.634, -88.690

Widespread tree damage occurred in Somonauk with a few trees snapped very near their base and minor damage to houses, consisting mainly of a few shingles blown off.

Thunderstorm Wind, La Salle

When
August 10, 2:02 PM CST to 2:04 PM CST
Where
La Salle County, 0.91 mi NNW of Streator West to 0.1 mi NNW of Streator Arpt
Measured
74 kt (85 mph) estimated gust
Reported by
Newspaper
Coordinates
41.131, -88.859

Trees, tree limbs and power lines were blown down in Streator. Some trees were uprooted, including at City Park. Many roads were blocked by fallen trees. A tree fell onto three cars near 7th Street, crushing two of the cars. Part of the roof of the YMCA was blown off and nearby, a metal roof was partially blown off of a drive-in restaurant. Numerous utility poles were damaged and much of the city lost power.

Thunderstorm Wind, De Kalb

When
August 10, 2:02 PM CST
Where
De Kalb County, 4.24 mi NNW of Sandwich to 4.21 mi SSW of Hinckley
Measured
78 kt (90 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.706, -88.652

Seven large and new utility poles were snapped about 10 feet up from their base along Somonauk Road, just south of Chicago Road.

Thunderstorm Wind, De Kalb

When
August 10, 2:02 PM CST
Where
De Kalb County, 6 mi N of Somonauk
Measured
65 kt (75 mph) estimated gust
Reported by
Social Media
Coordinates
41.717, -88.680

Several trees were blown down, a grain bin was damaged and the roof of a shed was blown off.

Tornado, McHenry

When
August 10, 2:05 PM CST to 2:11 PM CST
Where
McHenry County, 5.12 mi WSW of Coral to 0.62 mi ENE of Coral
Rating
EF1
Path length
5.73 mi
Path width
200 yd
Reported by
NWS Storm Survey
Coordinates
42.181, -88.655

A tornado with peak winds of 95 mph touched down just south of Harmony Road, west of Payne Road where several large tree limbs were blown down. Tree damage occurred immediately northeast of Interstate 90. Farm sheds were heavily damaged near Anthony and Riley Roads. Tree limbs were blown down and corn was blown down in a convergent pattern in this area. Two utility poles were slightly leaning along Route 23, south of Grange Road. A single family home was heavily damaged near Maple Street. Mainly tree limbs were blown down along the remaining path. The tornado lifted near Coral and Dunham Roads.

Thunderstorm Wind, De Kalb

When
August 10, 2:05 PM CST to 2:06 PM CST
Where
De Kalb County, 0.6 mi W of Sandwich to 0.67 mi E of Sandwich
Measured
55 kt (63 mph) estimated gust
Reported by
Broadcast Media
Coordinates
41.649, -88.632

Tree limbs and power lines were blown down in Sandwich.

Thunderstorm Wind, Kane

When
August 10, 2:09 PM CST to 2:11 PM CST
Where
Kane County, 0.61 mi NW of Maple Park to 0.47 mi NE of Maple Park
Measured
70 kt (81 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.906, -88.609

Multiple trees were blown down, some 20 inches in diameter. Power lines and fences were also blown down.

Thunderstorm Wind, Kendall

When
August 10, 2:11 PM CST to 2:12 PM CST
Where
Kendall County, 0.85 mi WSW of Plano to 0.33 mi SSE of Plano
Measured
55 kt (63 mph) estimated gust
Reported by
Broadcast Media
Coordinates
41.666, -88.545

Tree limbs and power lines were blown down in Plano.

Tornado, Kane

When
August 10, 2:12 PM CST to 2:14 PM CST
Where
Kane County, 2.36 mi ENE of Maple Park to 2.25 mi S of Virgil
Rating
EF1
Path length
1.21 mi
Path width
40 yd
Reported by
Trained Spotter
Coordinates
41.917, -88.561

A tornado with peak winds of 90 mph touched down just west of Thatcher Road, northeast of Maple Park and ended near Meredith Road. Drone footage revealed a narrow swath of corn flattened in a convergent pattern. Damage to a barn occurred with a near complete removal of the gabled roof. The path of this tornado was determined, in part, using high resolution satellite imagery.

Thunderstorm Wind, Kendall

When
August 10, 2:14 PM CST
Where
Kendall County, 0.86 mi NW of Fox
Measured
56 kt (64 mph) measured gust
Reported by
Public
Coordinates
41.630, -88.510

A private weather station measured a wind gust to 65 mph.

Thunderstorm Wind, Kendall

When
August 10, 2:14 PM CST to 2:16 PM CST
Where
Kendall County, 0.97 mi NW of Yorkville to 1.08 mi NE of Yorkville
Measured
65 kt (75 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.641, -88.461

Trees, tree limbs and power lines were blown down in Yorkville.

Thunderstorm Wind, Grundy

When
August 10, 2:15 PM CST
Where
Grundy County, 2.33 mi WNW of Verona
Measured
65 kt (75 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.235, -88.540

A barn had two large doors blown out along Gonnam Road.

Thunderstorm Wind, Grundy

When
August 10, 2:15 PM CST
Where
Grundy County, 1.23 mi WNW of Verona
Measured
65 kt (75 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.225, -88.523

Several trees were snapped.

Thunderstorm Wind, Kane

When
August 10, 2:15 PM CST
Where
Kane County, 3.27 mi E of Maple Park
Measured
55 kt (63 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.895, -88.537

Damage to traffic signals and a 4 inch tree limb blown down was reported at the intersection of Meredith Road and Route 38.

Thunderstorm Wind, Kane

When
August 10, 2:15 PM CST
Where
Kane County, 2.79 mi E of Kaneville
Measured
55 kt (63 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.828, -88.466

An 8 inch diameter tree was snapped near Route 47 and Nottingham Drive.

Thunderstorm Wind, Kane

When
August 10, 2:15 PM CST
Where
Kane County, 3.32 mi W of Elburn
Measured
50 kt (58 mph) estimated gust
Reported by
Newspaper
Coordinates
41.883, -88.534

A football field goal post was blown over at Kaneland High School.

Tornado, Kendall

When
August 10, 2:15 PM CST to 2:26 PM CST
Where
Kendall County, 0.66 mi SSW of Yorkville to 7.54 mi ENE of Plattville
Rating
EF1
Path length
10.47 mi
Path width
250 yd
Continued into
Will, Il (LOT)
Reported by
NWS Storm Survey
Coordinates
41.621, -88.455

A tornado with peak winds of 105 mph touched down near Walsh Drive, just north of Route 71. A pergola was destroyed, siding was ripped off a house and parts of a fence and a tree were thrown over a road. Eyewitness accounts indicated the debris was lifted and twirled. The tornado continued moving east southeast producing damage to trees along Route 126. The most significant damage was found east of Schlapp Road along Wheeler Road where trees were mangled, a farm building was destroyed with debris deposited in a nearby field and a large grain bin was bent inward. Wood panels were thrown into the ground leaving scour marks in the grass. Six utility poles were snapped along Ridge Road and a 1000-1500 pound auger was moved about 50 feet. This is where the tornado likely reached peak intensity. The tornado continued southeast crossing into Will County just south of Renwick Road.

Thunderstorm Wind, Grundy

When
August 10, 2:16 PM CST
Where
Grundy County, 0.28 mi S of Verona
Measured
65 kt (75 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.216, -88.501

A grain bin was blown down near State Street in Verona. Several large tree limbs were also blown down.

Thunderstorm Wind, Grundy

When
August 10, 2:16 PM CST to 2:17 PM CST
Where
Grundy County, 1.24 mi WNW of Verona to 0.4 mi WNW of Verona
Measured
65 kt (75 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.228, -88.521

Pockets of flattened corn stalks were reported northwest of Verona.

Thunderstorm Wind, Kane

When
August 10, 2:16 PM CST
Where
Kane County, Aurora Muni Arpt
Measured
54 kt (62 mph) measured gust
Reported by
ASOS
Coordinates
41.770, -88.470

A wind gust was measured to 62 mph at the Aurora Municipal Airport.

Thunderstorm Wind, Kane

When
August 10, 2:16 PM CST
Where
Kane County, 1.03 mi SW of Aurora Muni Arpt
Measured
55 kt (63 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.758, -88.481

Tree damage was reported blocking Fays Lane west of Sugar Grove.

Thunderstorm Wind, Grundy

When
August 10, 2:17 PM CST
Where
Grundy County, 0.88 mi SE of Verona
Measured
65 kt (75 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.210, -88.490

A grain bin was damaged.

Thunderstorm Wind, Grundy

When
August 10, 2:17 PM CST
Where
Grundy County, 1.03 mi SSE of Verona to 1 mi SSE of Verona
Measured
60 kt (69 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.206, -88.492

Two utility poles were snapped along Verona Road.

Thunderstorm Wind, Livingston

When
August 10, 2:17 PM CST to 2:18 PM CST
Where
Livingston County, Dwight
Measured
70 kt (81 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.080, -88.430

Numerous metal farm buildings were damaged including roofs and metal siding blown off. A large tree was snapped and fell onto a house.

Thunderstorm Wind, Grundy

When
August 10, 2:18 PM CST
Where
Grundy County, 2.22 mi SE of Verona
Measured
70 kt (81 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.196, -88.472

Several metal panels of a large shed were blown in on one side and blown out on another side.

Thunderstorm Wind, Grundy

When
August 10, 2:19 PM CST
Where
Grundy County, 2.55 mi SSW of Mazon
Measured
60 kt (69 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.197, -88.452

Minor roof damage occurred to a house along Burkhart Road.

Thunderstorm Wind, Grundy

When
August 10, 2:19 PM CST
Where
Grundy County, 3.34 mi S of Mazon
Measured
65 kt (75 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.182, -88.436

Large trees were snapped and numerous tree limbs were blown down near Gardener and Dwight Roads.

Thunderstorm Wind, Grundy

When
August 10, 2:19 PM CST
Where
Grundy County, 4.49 mi S of Mazon
Measured
60 kt (69 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.165, -88.435

A utility pole was snapped.

Thunderstorm Wind, McHenry

When
August 10, 2:19 PM CST to 2:20 PM CST
Where
McHenry County, 0.7 mi SSE of Woodstock Arpt to 0.69 mi E of Woodstock
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
42.320, -88.466

Tree limbs and power lines were blown down in Woodstock with some roads blocked.

Thunderstorm Wind, Kane

When
August 10, 2:19 PM CST to 2:21 PM CST
Where
Kane County, 2.36 mi SW of Lovedale to 2.16 mi NNE of Scraper Moecherville
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.760, -88.387

Trees, tree limbs and power lines were blown down in Aurora. Several roads were blocked by fallen trees.

Thunderstorm Wind, Grundy

When
August 10, 2:20 PM CST
Where
Grundy County, 5.21 mi S of Mazon
Measured
60 kt (69 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.155, -88.422

Large tree limbs were blown down.

Thunderstorm Wind, Kendall

When
August 10, 2:20 PM CST
Where
Kendall County, Yorkville
Measured
60 kt (69 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.630, -88.450

Several trees and large tree limbs were blown down.

Thunderstorm Wind, Grundy

When
August 10, 2:21 PM CST
Where
Grundy County, 0.79 mi NE of Mazon
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.237, -88.418

One grain bin was destroyed and a second grain bin was damaged. Nearby corn fields had partial damage with stalks blown down near Mazon.

Thunderstorm Wind, Kane

When
August 10, 2:22 PM CST to 2:23 PM CST
Where
Kane County, 0.73 mi W of Batavia to 1.33 mi E of Batavia
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.851, -88.334

Multiple trees and power lines were blown down throughout Batavia.

Thunderstorm Wind, Kane

When
August 10, 2:23 PM CST
Where
Kane County, 0.56 mi WNW of Geneva
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
41.884, -88.309

An Oak tree was blown down blocking Fulton Street.

Thunderstorm Wind, Kane

When
August 10, 2:25 PM CST
Where
Kane County, 0.69 mi SE of St Charles
Measured
55 kt (63 mph) estimated gust
Reported by
Public
Coordinates
41.913, -88.310

A 14 inch diameter tree was split in half in St. Charles. Power lines were also blown down.

Thunderstorm Wind, Grundy

When
August 10, 2:26 PM CST
Where
Grundy County, 0.76 mi NNE of East Brooklyn
Measured
60 kt (69 mph) estimated gust
Reported by
Social Media
Coordinates
41.180, -88.265

A pontoon boat was flipped over near Gardener.

Tornado, Will

When
August 10, 2:26 PM CST to 2:30 PM CST
Where
Will County, 1.35 mi NNW of Caton Farm to 1.91 mi W of Crystal Lawns
Rating
EF1
Path length
3.98 mi
Path width
250 yd
Reported by
NWS Storm Survey
Coordinates
41.589, -88.257

A tornado touched down in central Kendall County and moved southeast crossing into Will County just south of Renwick Road. Tree damage occurred along the path in Will County including a tree blown down near Caton Farm and Drauden Road. Minor roof damage occurred with some shingles blown off and some fences were blown down. One house lost half of the shingles on its roof with vents torn off, just east of Route 59. The tornado lifted near Caton Farm Road, just west of Interstate 55.

Thunderstorm Wind, Kendall

When
August 10, 2:26 PM CST
Where
Kendall County, 4.63 mi ESE of Oswego
Measured
60 kt (69 mph) estimated gust
Reported by
Public
Coordinates
41.648, -88.271

Damage to siding of a house was reported along with small tree limbs blown down nearby.

Hail, Grundy

When
August 10, 2:27 PM CST to 2:28 PM CST
Where
Grundy County, Morris
Measured
1 in hail
Reported by
Trained Spotter
Coordinates
41.370, -88.420

Thunderstorm Wind, Du Page

When
August 10, 2:27 PM CST
Where
Du Page County, 0.72 mi SE of Wayne
Measured
55 kt (63 mph) estimated gust
Reported by
County Official
Coordinates
41.942, -88.241

A tree was blown down near Nancy Lane and Powis Road.

Hail, Grundy

When
August 10, 2:29 PM CST to 2:31 PM CST
Where
Grundy County, 1.1 mi NW of Morris
Measured
1.75 in hail
Reported by
Law Enforcement
Coordinates
41.383, -88.433

Golf ball size hail was reported near Interstate 80 and Lisbon Road.

Thunderstorm Wind, McHenry

When
August 10, 2:29 PM CST
Where
McHenry County, 1.37 mi NE of Crystal Lake
Measured
55 kt (63 mph) estimated gust
Reported by
Newspaper
Coordinates
42.246, -88.315

A large tree limb was blown down blocking Ellsworth Street.

Thunderstorm Wind, Livingston

When
August 10, 2:30 PM CST
Where
Livingston County, 0.56 mi W of Forrest
Measured
60 kt (69 mph) estimated gust
Reported by
Social Media
Coordinates
40.751, -88.411

Tree damage was reported in Forrest.

Thunderstorm Wind, McHenry

When
August 10, 2:30 PM CST
Where
McHenry County, 0.73 mi NNW of Richmond
Measured
60 kt (69 mph) estimated gust
Reported by
Trained Spotter
Coordinates
42.480, -88.305

A tree over one foot in diameter was snapped near Route 12 and Route 173.

Thunderstorm Wind, Will

When
August 10, 2:30 PM CST to 2:38 PM CST
Where
Will County, 1.77 mi W of Crystal Lawns to 0.94 mi SSW of Raynor Park
Measured
74 kt (85 mph) estimated gust
Reported by
NWS Employee
Coordinates
41.566, -88.184

Widespread wind damage occurred across much of northwest Joliet from Caton Farm Road and Interstate 55 southeast through Larkin Avenue and Black Road. Several hundred trees were damaged with hundreds of tree limbs blown down. Large tree limbs blocked some roads. A few pine trees had the top of the tree sheared off. Power lines were blown down in many areas. Hundreds of residential fences were damaged with many sections of fencing blown down. Some homes suffered minor roof damage with primarily some shingles blown off.

Thunderstorm Wind, Kane

When
August 10, 2:30 PM CST to 2:31 PM CST
Where
Kane County, 1.46 mi WSW of Carpentersville to 0.4 mi SE of Carpentersville
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
42.125, -88.278

Several whole trees were uprooted in Carpentersville along with numerous healthy 6 inch diameter tree limbs blown down. Fire crews responded to 14 reports of power lines blown down. One of these power lines started a fire in a detached garage on Golfview Lane. A tree fell onto a roof of a house on Wakefield Drive, leaving the house uninhabitable.

Hail, Kendall

When
August 10, 2:30 PM CST
Where
Kendall County, Oswego
Measured
1 in hail
Reported by
Public
Coordinates
41.680, -88.350

Nickel to quarter size hail was reported in Oswego.

Thunderstorm Wind, Will

When
August 10, 2:31 PM CST to 2:32 PM CST
Where
Will County, 1.28 mi WNW of Plainfield to 0.78 mi NNE of Plainfield
Measured
60 kt (69 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.610, -88.221

Large trees and power lines were blown down across Plainfield.

Thunderstorm Wind, McHenry

When
August 10, 2:31 PM CST to 2:32 PM CST
Where
McHenry County, 0.8 mi WSW of Spring Grove to 0.72 mi ESE of Spring Grove
Measured
65 kt (75 mph) estimated gust
Reported by
Trained Spotter
Coordinates
42.444, -88.243

Trees and tree limbs were blown down in Spring Grove. Several healthy trees were snapped near their base.

Thunderstorm Wind, Will

When
August 10, 2:32 PM CST
Where
Will County, 1.27 mi N of Walker
Measured
73 kt (84 mph) measured gust
Reported by
Mesonet
Coordinates
41.638, -88.197

A wind gust to 84 mph was measured.

Thunderstorm Wind, Du Page

When
August 10, 2:33 PM CST to 2:35 PM CST
Where
Du Page County, 1 mi W of Warrenville to 1 mi E of Warrenville
Measured
50 kt (58 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.820, -88.189

Tree limbs up to 6 inches in diameter were blown down all over Warrenville.

Thunderstorm Wind, Grundy

When
August 10, 2:35 PM CST
Where
Grundy County, Morris Muni Arpt
Measured
51 kt (59 mph) measured gust
Reported by
AWOS
Coordinates
41.430, -88.420

A wind gust to 59 mph was measured at the Morris Municipal Airport.

Tornado, Du Page

When
August 10, 2:35 PM CST to 2:36 PM CST
Where
Du Page County, 0.85 mi ESE of Wheaton to 1.19 mi E of Wheaton
Rating
EF1
Path length
0.36 mi
Path width
100 yd
Reported by
NWS Storm Survey
Coordinates
41.867, -88.104

A brief tornado with peak winds of 90 mph touched down near Seminary Avenue and Scott Street and moved northeast where it knocked a roughly 50 foot steeple around to the north side of the College Church of Wheaton. The tornado then produced minor tree damage before lifting near Collage Avenue and Howard Street.

Thunderstorm Wind, Lake

When
August 10, 2:36 PM CST
Where
Lake County, 2.27 mi W of Barrington
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
42.176, -88.174

Trees and power lines were blown down on Cuba Road east of Route 14.

Thunderstorm Wind, Du Page

When
August 10, 2:36 PM CST to 2:38 PM CST
Where
Du Page County, 1.28 mi WSW of Glen Ellyn to 0.91 mi ENE of Glen Ellyn
Measured
78 kt (90 mph) estimated gust
Reported by
NWS Storm Survey
Coordinates
41.872, -88.092

A corridor of enhanced straight line winds developed near President Street in northeast Wheaton and continued across northern Glenn Ellyn, ending northeast of Lake Ellyn. Trees and utility poles were damaged along this corridor with the peak of the damage occurring east of Main Street and towards Lake Ellyn Park. Damage was consistent with wind speeds up to 90 mph.

Thunderstorm Wind, Cook

When
August 10, 2:36 PM CST
Where
Cook County, 2.32 mi WNW of Hanover Park
Measured
60 kt (69 mph) estimated gust
Reported by
Trained Spotter
Coordinates
42.028, -88.224

A B-Class truck with a trailer was blown over at Irving Park Road and Schaumburg Road.

Thunderstorm Wind, Will

When
August 10, 2:36 PM CST to 2:40 PM CST
Where
Will County, 0.99 mi E of (Jot) Joliet Distric to 1.36 mi WSW of Ridgewood
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
41.522, -88.161

Scattered tree damage occurred in Joliet with broken tree limbs in several intersections along Jefferson Street. At least one car was damaged by a large tree in the Cathedral Area in Joliet, where power lines were blown down. Numerous other tree limbs were blown down.

Thunderstorm Wind, Kankakee

When
August 10, 2:36 PM CST to 2:37 PM CST
Where
Kankakee County, 0.23 mi W of Herscher to 0.77 mi E of Herscher
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.050, -88.104

Trees, tree limbs and power lines were blown down in Herscher. Almost everyone lost power.

Thunderstorm Wind, Will

When
August 10, 2:37 PM CST to 2:41 PM CST
Where
Will County, 0.99 mi NW of Raynor Park to 0.67 mi NE of Lidice
Measured
74 kt (85 mph) estimated gust
Reported by
Local Official
Coordinates
41.558, -88.136

Widespread tree damage occurred in Crest Hill with the east side of town hit the hardest. Numerous large tree limbs were blown down along with some trees, blocking several roads. Powerlines were also blown down. A roof of an apartment building on Arbor Lane was partially blown off, displacing 10 families who lived there.

Thunderstorm Wind, Will

When
August 10, 2:37 PM CST
Where
Will County, 0.78 mi WSW of Idylside
Measured
55 kt (63 mph) estimated gust
Reported by
NWS Employee
Coordinates
41.515, -88.133

Sporadic tree limbs 6 to 12 inches in diameter were blown down along McDonough Street.

Thunderstorm Wind, Du Page

When
August 10, 2:38 PM CST
Where
Du Page County, (Dpa)dupage Co Arpt
Measured
54 kt (62 mph) measured gust
Reported by
ASOS
Coordinates
41.900, -88.250

A wind gust to 62 mph was measured at the DuPage Airport.

Thunderstorm Wind, Will

When
August 10, 2:38 PM CST to 2:39 PM CST
Where
Will County, 1.74 mi E of Plainfield Clow Arpt to 2.15 mi SE of Barbers Corners
Measured
55 kt (63 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.696, -88.097

Large tree limbs and small trees were blown down in Bolingbrook.

Thunderstorm Wind, Kankakee

When
August 10, 2:38 PM CST to 2:39 PM CST
Where
Kankakee County, 0.79 mi W of Bonfield to 0.13 mi SSE of Bonfield
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.148, -88.065

Trees, tree limbs and power lines were blown down in Bonfield.

Thunderstorm Wind, Cook

When
August 10, 2:39 PM CST
Where
Cook County, Schaumburg
Measured
61 kt (70 mph) estimated gust
Reported by
Trained Spotter
Coordinates
42.030, -88.080

Wind gusts were estimated between 60 mph and 70 mph in Schaumburg.

Thunderstorm Wind, Lake

When
August 10, 2:39 PM CST
Where
Lake County, 0.39 mi NNW of Deer Park
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
42.156, -88.102

Trees and power lines were blown down on Ela Road north of Lake Cook Road.

Tornado, Du Page

When
August 10, 2:39 PM CST to 2:42 PM CST
Where
Du Page County, 0.39 mi NNE of Lombard to 0.03 mi NNW of South Addison
Rating
EF1
Path length
2.15 mi
Path width
200 yd
Reported by
NWS Storm Survey
Coordinates
41.885, -88.017

A tornado with peak winds of 95 mph touched down near Main and Maple Streets, just east of Lilacia Park. The tornado moved northeast uprooting some trees and snapping other trees. More than 200 homes in Lombard suffered some amount of damage, a few suffered significant roof damage. The worst damage occurred near the Lombard Common just south of St. Charles Road. Tree damage continued along the path including part of a large tree blown down near Schafer Elementary School. A one foot diameter tree was blown down onto a house. Another house suffered minor roof and siding damage just north of the Jefferson Middle School and the tornado lifted northeast of the Jefferson Middle School.

Thunderstorm Wind, Will

When
August 10, 2:39 PM CST to 2:40 PM CST
Where
Will County, 1.96 mi WNW of Romeoville to 0.58 mi NNW of Romeoville
Measured
55 kt (63 mph) estimated gust
Reported by
Newspaper
Coordinates
41.638, -88.106

Tree limbs and power lines were blown down in Romeoville.

Thunderstorm Wind, Du Page

When
August 10, 2:40 PM CST
Where
Du Page County, 2.07 mi WNW of Willowbrook
Measured
55 kt (63 mph) estimated gust
Reported by
NWS Employee
Coordinates
41.759, -88.008

Considerable tree damage was reported along Main Street, north of 75th Street.

Thunderstorm Wind, Lake

When
August 10, 2:40 PM CST
Where
Lake County, 0.7 mi WNW of Volo
Measured
60 kt (69 mph) estimated gust
Reported by
Emergency Manager
Coordinates
42.333, -88.183

Tree limbs 8 to 10 inches in diameter were blown down near Sullivan Lake Boulevard and Game Trail. Some of the tree limbs were 20 feet in length. Siding was blown off of an apartment building.

Thunderstorm Wind, Du Page

When
August 10, 2:40 PM CST
Where
Du Page County, 0.69 mi S of (O6c) Schaumburg Regional Airport
Measured
55 kt (63 mph) estimated gust
Reported by
Public
Coordinates
41.980, -88.100

Large tree limbs were blown down west of Roselle.

Thunderstorm Wind, Will

When
August 10, 2:41 PM CST
Where
Will County, 0.39 mi NW of Lockport Lewis Arpt
Measured
50 kt (58 mph) measured gust
Reported by
Official NWS Observations
Coordinates
41.604, -88.085

A wind gust to 58 mph was measured at the National Weather Service office in Romeoville. Small tree limbs were observed flying past the window at the time of the peak gust.

Tornado, Lake

When
August 10, 2:41 PM CST to 2:45 PM CST
Where
Lake County, 2.04 mi W of Channel Lake to 2.01 mi NNW of Channel Lake
Rating
EF1
Path length
1.75 mi
Path width
150 yd
Continued into
Kenosha, Wi (MKX)
Reported by
NWS Storm Survey
Coordinates
42.475, -88.189

A tornado with peak winds of 90 mph touched down south of Route 173 and moved northeast to the state line where it crossed into Kenosha County in southeast Wisconsin. Mainly tree damage occurred along the path in Lake County with several trees uprooted with some minor structural damage just south of the state line.

Thunderstorm Wind, Will

When
August 10, 2:41 PM CST
Where
Will County, 0.82 mi SE of Forest Park
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
41.543, -88.037

A large and old brick and concrete structure that held a movie screen at an outdoor drive-in movie theater was destroyed with about 80 percent of the structure collapsed. Most of the debris fell in place and crushed a semi trailer that had been parked near the structure.

Thunderstorm Wind, Lake

When
August 10, 2:42 PM CST to 2:43 PM CST
Where
Lake County, 0.41 mi NNE of Grass Lake to 1.51 mi W of Loon Lake
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
42.435, -88.127

A 1 to 2 foot diameter tree was snapped a few feet above the ground near Woodside Avenue. Trees and power lines were blown down on Grass Lake Road, east of Route 59.

Thunderstorm Wind, Will

When
August 10, 2:42 PM CST to 2:43 PM CST
Where
Will County, 0.81 mi SW of Lockport to 1.04 mi SE of Lockport
Measured
55 kt (63 mph) estimated gust
Reported by
Newspaper
Coordinates
41.591, -88.059

Tree limbs and power lines were blown down in Lockport.

Hail, Du Page

When
August 10, 2:43 PM CST to 2:44 PM CST
Where
Du Page County, 0.74 mi S of Butterfield West
Measured
1 in hail
Reported by
Trained Spotter
Coordinates
41.859, -88.053

Quarter size hail was reported near Route 53 and Roosevelt Road.

Thunderstorm Wind, Du Page

When
August 10, 2:43 PM CST to 2:44 PM CST
Where
Du Page County, 1.38 mi N of Elmhurst to 1.68 mi NE of Elmhurst
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
41.900, -87.951

Tree limbs and power lines were blown down in Elmhurst.

Thunderstorm Wind, Du Page

When
August 10, 2:43 PM CST to 2:45 PM CST
Where
Du Page County, 0.39 mi E of Westmont to 0.39 mi NNE of Hinsdale
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
41.799, -87.963

Large tree limbs were blown down in Clarendon Hills and Hinsdale. The worst of the damage was north of the railroad tracks in Clarendon Hills where roads were blocked. The worst damage in Hinsdale appeared to be in the northeast part of the village.

Thunderstorm Wind, Lake

When
August 10, 2:44 PM CST to 2:45 PM CST
Where
Lake County, 1.11 mi NNW of Round Lake Hgts to 0.39 mi SW of Lindenhurst
Measured
65 kt (75 mph) estimated gust
Injuries
1 direct, 0 indirect
Reported by
Newspaper
Coordinates
42.415, -88.088

Trees, tree limbs and power lines were blown down in Lake Villa. One tree fell onto a house in unincorporated Lake Villa causing the homeowner to sustain a minor injury. Another tree fell onto a SUV causing significant damage to the roof and windshield. Trees and power lines were blown down blocking portions of Route 83.

Thunderstorm Wind, Will

When
August 10, 2:44 PM CST to 2:46 PM CST
Where
Will County, 0.52 mi NNW of New Lenox Gear Arpt to 0.44 mi N of Spencer
Measured
78 kt (90 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.507, -87.983

Significant wind damage occurred in New Lenox with many trees uprooted and many roads blocked by fallen trees. Hundreds of trees were uprooted or snapped along Cedar Road and Joliet Highway.

Thunderstorm Wind, Lake

When
August 10, 2:45 PM CST
Where
Lake County, 0.86 mi E of Grayslake
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
42.351, -88.033

Trees and power lines were blown down along Route 83 in Grayslake.

Thunderstorm Wind, Will

When
August 10, 2:45 PM CST
Where
Will County, 2.19 mi S of Brisbane
Measured
60 kt (69 mph) estimated gust
Reported by
Public
Coordinates
41.469, -87.964

Traffic signals and a large tree were damaged near Delaney and Cedar Roads.

Funnel Cloud, Will

When
August 10, 2:45 PM CST
Where
Will County, 0.92 mi WSW of Fairmont
Reported by
Trained Spotter
Coordinates
41.567, -88.087

A funnel cloud was observed from Caton Farm Road and Route 53.

Thunderstorm Wind, Lake

When
August 10, 2:46 PM CST
Where
Lake County, 0.63 mi ENE of Buffalo Grove
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
42.153, -87.958

Trees and power lines were blown down along Route 83 in Buffalo Grove.

Thunderstorm Wind, Will

When
August 10, 2:46 PM CST to 2:47 PM CST
Where
Will County, 0.59 mi W of Homer Glen to 0.75 mi E of Homer Glen
Measured
55 kt (63 mph) estimated gust
Reported by
Newspaper
Coordinates
41.600, -87.951

Tree limbs and power lines were blown down in Homer Glen.

Thunderstorm Wind, Kankakee

When
August 10, 2:47 PM CST to 2:48 PM CST
Where
Kankakee County, 0.47 mi NW of Limestone to 0.55 mi ENE of Limestone
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.134, -87.977

Trees, tree limbs and power lines were blown down in Limestone.

Thunderstorm Wind, Will

When
August 10, 2:48 PM CST
Where
Will County, 0.52 mi E of Mokena
Measured
56 kt (64 mph) measured gust
Reported by
Trained Spotter
Coordinates
41.530, -87.870

Wind gusts to 65 mph were measured with small tree limbs blown down.

Thunderstorm Wind, Cook

When
August 10, 2:48 PM CST to 2:49 PM CST
Where
Cook County, 0.05 mi WSW of Hillside to 0.15 mi E of Westchester
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
41.850, -87.901

Tree limbs and power lines were blown down in Westchester. At least one tree was struck by lightning.

Thunderstorm Wind, Cook

When
August 10, 2:49 PM CST
Where
Cook County, (Ord) Chicago O'Hare Airport
Measured
54 kt (62 mph) measured gust
Reported by
ASOS
Coordinates
41.980, -87.900

A wind gust was measured to 62 mph at Chicago O'Hare Airport.

Thunderstorm Wind, Lake

When
August 10, 2:49 PM CST
Where
Lake County, 0.16 mi WNW of Halfday
Measured
50 kt (58 mph) estimated gust
Reported by
Newspaper
Coordinates
42.201, -87.933

Milwaukee Avenue was closed between Route 22 and Old Half Day Road due do a power line blown down.

Thunderstorm Wind, Cook

When
August 10, 2:50 PM CST
Where
Cook County, 0.46 mi ENE of Rosemont
Measured
50 kt (58 mph) estimated gust
Reported by
Newspaper
Coordinates
41.983, -87.862

A light pole was blown down along southbound River Road near Interstate 190.

Thunderstorm Wind, Will

When
August 10, 2:50 PM CST to 2:51 PM CST
Where
Will County, 0.96 mi W of Frankfort to 1.08 mi E of Frankfort
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.499, -87.868

Trees, tree limbs and power lines were blown down in Frankfort. Some utility poles were damaged.

Thunderstorm Wind, Cook

When
August 10, 2:50 PM CST
Where
Cook County, 0.57 mi ESE of Broadview
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.848, -87.839

A narrow corridor of wind damage occurred along 23rd Street in North Riverside. One large tree fell between two houses near 10th Avenue causing some damage to aluminum siding. Another large tree near 2nd Avenue was completely uprooted, narrowly missing a house.

Thunderstorm Wind, Cook

When
August 10, 2:50 PM CST to 2:51 PM CST
Where
Cook County, Orland Park to 0.55 mi W of Villa West
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
41.630, -87.870

Tree limbs and power lines were blown down in Orland Park. A fence was damaged in the Catalina subdivision.

Hail, Cook

When
August 10, 2:50 PM CST to 3:00 PM CST
Where
Cook County, 0.9 mi W of Glencoe to 0.49 mi N of Glencoe
Measured
0.88 in hail
Reported by
Public
Coordinates
42.132, -87.767

Nickel size hail fell across Glencoe for 10 minutes.

Thunderstorm Wind, Kankakee

When
August 10, 2:50 PM CST to 2:53 PM CST
Where
Kankakee County, 0.15 mi ENE of West Kankakee to 1.36 mi E of Kankakee
Measured
70 kt (81 mph) estimated gust
Reported by
Newspaper
Coordinates
41.121, -87.897

Numerous trees were blown down and uprooted in Kankakee. Tree limbs and power lines were also blown down. Many trees fell onto roofs and garages causing damage. The hardest hit areas were on the west side of Kankakee and the Riverview neighborhood where streets were blocked by the fallen trees.

Thunderstorm Wind, Kankakee

When
August 10, 2:50 PM CST to 2:51 PM CST
Where
Kankakee County, 1.36 mi WSW of Altorf to 0.67 mi ESE of Altorf
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.176, -87.895

Several trees and power lines were blown down in Bourbonnais. At least two homes were damaged by trees falling through the roof.

Thunderstorm Wind, Cook

When
August 10, 2:50 PM CST to 3:05 PM CST
Where
Cook County, 7 mi W of Chicago to 0.5 mi E of Chicago
Measured
70 kt (81 mph) estimated gust
Reported by
Newspaper
Coordinates
41.880, -87.766

Widespread tree damage occurred across Chicago. At least 11,000 trees were blown down. Many more trees were damaged. Dozens of vehicles were damaged by falling trees and tree limbs, some vehicles were crushed. Numerous roads were blocked by the fallen trees. Hundreds of power lines were blown down, some started small fires.

Thunderstorm Wind, Iroquois

When
August 10, 2:51 PM CST
Where
Iroquois County, 0.99 mi W of Danforth
Measured
60 kt (69 mph) estimated gust
Reported by
Law Enforcement
Coordinates
40.822, -87.999

A semi truck was overturned on Interstate 57 near mile marker 287.

Thunderstorm Wind, Cook

When
August 10, 2:51 PM CST to 2:52 PM CST
Where
Cook County, 0.78 mi ENE of Congress Park to 0.8 mi WSW of Hollywood
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.824, -87.856

Tree damage occurred in Brookfield with the worst of the damage north of the railroad tracks. A corridor of widespread damage occurred along Grant Avenue where large tree limbs were blocking streets and sidewalks. A few larger tree limbs fell onto parked cars. A tree was split down the middle near Cleveland Avenue with part of the tree landing on the roof of a brick bungalow.

Thunderstorm Wind, Kankakee

When
August 10, 2:51 PM CST to 2:53 PM CST
Where
Kankakee County, 0.61 mi SSW of Bourbonnais to 1.68 mi NNE of Kankakee
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.143, -87.886

Trees, tree limbs and power lines were blown down in Bradley. The hardest hit areas were Blatt and Meadowview subdivisions, west of Kennedy Drive. A 60 inch diameter tree on Marla Terrace was snapped at its base and fell onto a pickup truck, a garage and another vehicle in the garage.

Thunderstorm Wind, Cook

When
August 10, 2:51 PM CST to 2:52 PM CST
Where
Cook County, 0.34 mi NNE of Hollywood to 0.86 mi ENE of Riverside
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
41.835, -87.829

Scattered tree limbs were blown down across Riverside.

Thunderstorm Wind, Cook

When
August 10, 2:51 PM CST to 2:53 PM CST
Where
Cook County, 1.37 mi W of River Grove to 0.76 mi ENE of Elmwood Park
Measured
70 kt (81 mph) estimated gust
Reported by
Newspaper
Coordinates
41.923, -87.846

Trees, tree limbs and power lines were blown down in River Grove and Elmwood Park. Several cars and houses were damaged by fallen trees. Several roads were blocked by the fallen trees.

Thunderstorm Wind, Cook

When
August 10, 2:52 PM CST to 2:53 PM CST
Where
Cook County, 0.8 mi WSW of Hanson Park to 1.25 mi NW of River Forest
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.894, -87.833

Multiple trees were damaged in River Forest. A couple of tree limbs fell onto vehicles.

Thunderstorm Wind, Kankakee

When
August 10, 2:52 PM CST
Where
Kankakee County, 0.82 mi NW of Kankakee Gtr Arpt
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
41.079, -87.860

A semi truck was blown over in the Kankakee Walmart parking lot.

Thunderstorm Wind, Cook

When
August 10, 2:52 PM CST
Where
Cook County, 0.39 mi ENE of Dunning
Measured
65 kt (75 mph) estimated gust
Reported by
Public
Coordinates
41.942, -87.803

A garage collapsed near Roscoe Street and Nordica Avenue.

Thunderstorm Wind, Cook

When
August 10, 2:52 PM CST to 2:53 PM CST
Where
Cook County, 0.91 mi WSW of Oak Park to 0.42 mi SSE of Oak Park
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.885, -87.796

Numerous tree limbs were blown down in Oak Park. More than a dozen streets were blocked by the fallen tree limbs.

Thunderstorm Wind, Cook

When
August 10, 2:53 PM CST
Where
Cook County, 1.46 mi SSE of Hanson Park
Measured
60 kt (69 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.880, -87.813

A tree was blown down blocking a road in Forest Park.

Tornado, Cook

When
August 10, 2:54 PM CST to 2:59 PM CST
Where
Cook County, 0.38 mi WSW of Goeselville to 0.89 mi SSE of Posen
Rating
EF1
Path length
4.84 mi
Path width
300 yd
Reported by
NWS Storm Survey
Coordinates
41.618, -87.787

A tornado with peak winds of 100 mph touched just east of Harlem Avenue in Oak Forest then moved nearly due east along 151st Street producing tree damage and minor structural damage before lifting near the Interstate 57/294 interchange in Midlothian. Numerous trees were uprooted between Ridgeland Avenue and Cicero Avenue. The worst damage occurred between Cicero Avenue and Pulaski Road where several large trees and utility poles were snapped at their base. Tree damage continued east of Pulaski Road with fences blown down before the tornado lifted.

Thunderstorm Wind, Cook

When
August 10, 2:55 PM CST
Where
Cook County, (Mdw) Chicago Midway Airport
Measured
63 kt (72 mph) measured gust
Reported by
ASOS
Coordinates
41.780, -87.750

A wind gust to 72 mph was measured at Midway Airport.

Thunderstorm Wind, Cook

When
August 10, 2:55 PM CST
Where
Cook County, 0.37 mi SSW of Berwyn
Measured
55 kt (63 mph) estimated gust
Reported by
Public
Coordinates
41.846, -87.754

Tree damage was reported in Cicero.

Thunderstorm Wind, Cook

When
August 10, 2:55 PM CST
Where
Cook County, 0.63 mi NW of Burbank
Measured
56 kt (64 mph) measured gust
Reported by
COOP Observer
Coordinates
41.737, -87.777

A wind gust to 65 mph was measured in Burbank.

Thunderstorm Wind, Cook

When
August 10, 2:55 PM CST
Where
Cook County, 0.59 mi WSW of Kimberly Hgts
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
41.566, -87.790

Extensive damage occurred to several Maple trees near the First Baptist Church along 179th Street in Tinley Park. Several shingles were blown off the roof of the church. Some of the shingles were found more than two blocks away.

Thunderstorm Wind, Cook

When
August 10, 2:56 PM CST
Where
Cook County, 1.26 mi SSE of Dunning
Measured
65 kt (75 mph) estimated gust
Reported by
Broadcast Media
Coordinates
41.953, -87.760

A large sign for an auto dealer was blown down from south to north onto a car parked on Irving Park Road.

Thunderstorm Wind, Kankakee

When
August 10, 2:56 PM CST to 2:57 PM CST
Where
Kankakee County, 0.93 mi W of Aroma Park to 0.23 mi WNW of Aroma Park
Measured
65 kt (75 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.081, -87.818

Trees, tree limbs and power lines were blown down in Aroma Park.

Thunderstorm Wind, Cook

When
August 10, 2:57 PM CST
Where
Cook County, Oak Lawn
Measured
60 kt (69 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.720, -87.750

A large tree was uprooted in Oak Lawn.

Thunderstorm Wind, Cook

When
August 10, 2:57 PM CST
Where
Cook County, 0.42 mi ENE of Richton Park to 0.47 mi NE of Richton Park
Measured
60 kt (69 mph) estimated gust
Reported by
NWS Storm Survey
Coordinates
41.483, -87.713

Three utility poles were leaning near Suak Trail and Governor's Highway.

Tornado, Cook

When
August 10, 2:57 PM CST to 2:59 PM CST
Where
Cook County, 0.95 mi E of Park Forest South to 0.7 mi E of Park Forest
Rating
EF0
Path length
1.97 mi
Path width
350 yd
Reported by
NWS Storm Survey
Coordinates
41.469, -87.702

A tornado with peak winds of 85 mph touched down near the Will Cook County line, just west of Shabbona Drive. This tornado produced mainly tree damage along its path. The worst of the damage was confined to a small area near Marquette and Somonauk Parks, although very little structural damage was noted in this area. The tornado lifted over Schubert's Woods Forest Preserve.

Thunderstorm Wind, Cook

When
August 10, 2:57 PM CST to 2:58 PM CST
Where
Cook County, 0.92 mi SSW of Albany Park to 0.78 mi SE of Albany Park
Measured
83 kt (96 mph) estimated gust
Reported by
NWS Storm Survey
Coordinates
41.957, -87.736

A corridor of significant wind damage occurred in Chicago, starting immediately east of Interstate 90/94 near Berteau and Kildare Avenues and continued northeast to near Montrose and Lawndale Avenues. Significant tree damage occurred in this corridor with many trees snapped or uprooted. Roof damage occurred to a few apartment buildings along Kedvale Avenue, just south of Cullom Avenue. One building suffered damage to a brick wall. Damage occurred to the top of a brick business at the southeast corner of Pulaski Road and Elston Avenue. Vehicles were damaged by the falling bricks. Several roofs sustained damage northeast of Elston Avenue, just south of Montrose Avenue and a window was blown out of a house. Two utility poles were damaged near Avers Avenue. Three buildings along Montrose Avenue suffered significant roof damage just east of Hamlin Avenue. Two buildings had west and south facing windows blown out near Montrose Avenue and Lawndale Avenue. The damage in this corridor indicates peak winds of 95 mph.

Thunderstorm Wind, Cook

When
August 10, 2:57 PM CST
Where
Cook County, 1.69 mi WSW of Edgewater
Measured
74 kt (85 mph) measured gust
Reported by
Mesonet
Coordinates
41.980, -87.690

A wind gust to 85 mph was measured.

Thunderstorm Wind, Cook

When
August 10, 2:57 PM CST to 2:58 PM CST
Where
Cook County, 0.81 mi S of Avondale to 0.89 mi SSE of Avondale
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.928, -87.702

About 50 trees were knocked down or damaged along Logan Boulevard in the Logan Square neighborhood in Chicago. Tree limbs and power lines were also blown down.

Thunderstorm Wind, Cook

When
August 10, 2:58 PM CST to 2:59 PM CST
Where
Cook County, 1.13 mi NW of Flossmoor to 1.06 mi WSW of Homewood
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
41.543, -87.694

Tree limbs and power lines were blown down in Flossmoor.

Thunderstorm Wind, Cook

When
August 10, 2:58 PM CST
Where
Cook County, 1.99 mi SSW of Edgewater
Measured
60 kt (69 mph) estimated gust
Reported by
Public
Coordinates
41.966, -87.681

A large tree was snapped blocking Eastwood Avenue. Other large tree limbs were blown down nearby.

Thunderstorm Wind, Du Page

When
August 10, 2:59 PM CST
Where
Du Page County, (Dpa)dupage Co Arpt
Measured
52 kt (60 mph) measured gust
Reported by
ASOS
Coordinates
41.900, -88.250

A wind gust to 60 mph was measured at the DuPage Airport.

Thunderstorm Wind, Cook

When
August 10, 2:59 PM CST to 3:01 PM CST
Where
Cook County, 1.19 mi W of South Chicago Heights to 0.71 mi E of South Chicago Heights
Measured
60 kt (69 mph) estimated gust
Reported by
NWS Storm Survey
Coordinates
41.480, -87.653

Sporadic straight line wind damage occurred across South Chicago Heights and continued east to State Street.

Tornado, Cook

When
August 10, 2:59 PM CST to 3:04 PM CST
Where
Cook County, 0.68 mi NNE of Lincolnwood to 0.6 mi NE of Rogers Park
Rating
EF1
Path length
3.19 mi
Path width
300 yd
Reported by
NWS Storm Survey
Coordinates
42.009, -87.724

A tornado with peak winds of 110 mph touched down in the Lincolnwood neighborhood of Chicago near the intersection of Lunt and Hamlin Avenues. Tree damage occurred along most of the path of the tornado. At least two city blocks were impassable due to fallen trees. Numerous cars were totaled after trees fell on them. Utility poles were leaning along Touhy Avenue, just east of St. Louis Avenue. Significant tree damage including snapped trees, large trees uprooted and trees and tree limbs on vehicles, occurred between California Avenue and Rogers Phillip Park. The most intense damage occurred approximately one mile west of Lake Michigan where widespread tree damage occurred including large trees 1 to 2 feet in diameter snapped and uprooted. Minor roof damage also occurred in this area. The tornado continued east to the Lake Michigan shore where it became a waterspout as it moved east of Fargo Beach Park.

Thunderstorm Wind, Cook

When
August 10, 2:59 PM CST
Where
Cook County, 1.24 mi NE of Albany Park
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.981, -87.711

Large tree limbs fell onto a small car near Catalpa Avenue and Spaulding Avenue, trapping the occupants in the car. Firefighters had to cut the tree limbs away before the people could exit the car. No injuries were reported.

Thunderstorm Wind, Will

When
August 10, 3:00 PM CST to 3:01 PM CST
Where
Will County, 1.5 mi W of Steger to 1.15 mi E of Steger
Measured
65 kt (75 mph) estimated gust
Reported by
Emergency Manager
Coordinates
41.469, -87.659

Widespread wind damage was reported throughout Steger including trees blown down, trees on power lines and broken utility poles.

Thunderstorm Wind, Cook

When
August 10, 3:00 PM CST
Where
Cook County, 0.49 mi N of Park Forest
Measured
63 kt (72 mph) measured gust
Reported by
Amateur Radio
Coordinates
41.487, -87.678

A private weather station measured a wind gust to 72 mph on Fir Street.

Thunderstorm Wind, Cook

When
August 10, 3:00 PM CST to 3:01 PM CST
Where
Cook County, 0.6 mi SSE of Matteson to 1.14 mi WSW of Chicago Heights
Measured
75 kt (86 mph) estimated gust
Reported by
Newspaper
Coordinates
41.492, -87.695

Trees, tree limbs and power lines were blown down in Park Forest. Multiple vehicles were damaged by fallen trees. Several homes had roof or siding damage. Part of a brick wall collapsed off a house. Widespread tree damage occurred in forest preserve areas near Park Forest.

Thunderstorm Wind, Cook

When
August 10, 3:00 PM CST to 3:10 PM CST
Where
Cook County, 0.89 mi S of Dixmoor to 1.21 mi NNE of South Holland
Measured
78 kt (90 mph) estimated gust
Deaths
0 direct, 1 indirect
Reported by
NWS Storm Survey
Coordinates
41.617, -87.682

A corridor of significant straight line wind damage occurred from Harvey east to Calumet City. Numerous trees were uprooted and snapped along this corridor. Some roofs were damaged by falling trees; other roofs suffered minor shingle damage from the strong winds. Some of the worst damage was in Harvey in an area between Sibley Boulevard to the north and 159th Street to the south. Trees were snapped and uprooted and extensive damage occurred to utility poles and power lines, resulting in some portions of the power grid needing to be completely rebuilt. Almost everyone in Harvey lost power. An estimated 300 to 350 trees were blown down in Harvey. Almost every road in Harvey was blocked by some amount of tree damage. Significant tree damage was reported in forest preserve areas including in the Shabonna Woods Forest Preserve. Damage was consistent with wind speeds up to 90 mph.

One day later, on August 11th, just after noon, a 59 year old man was walking in the 15000 block of Merrill Avenue in unincorporated Thornton Township near Calumet City. He stepped on a downed power line that was live and collapsed in a grassy area where he died.

Thunderstorm Wind, Kankakee

When
August 10, 3:00 PM CST
Where
Kankakee County, 3.93 mi W of St Anne
Measured
60 kt (69 mph) estimated gust
Reported by
Public
Coordinates
41.013, -87.795

Tree damage was reported along E 7500S Road.

Thunderstorm Wind, Iroquois

When
August 10, 3:00 PM CST to 3:01 PM CST
Where
Iroquois County, 0.12 mi NE of Crescent City to 1.54 mi E of Crescent City
Measured
65 kt (75 mph) estimated gust
Reported by
Trained Spotter
Coordinates
40.771, -87.868

Large trees and utility poles were blown down. A billboard was also damaged.

Thunderstorm Wind, Cook

When
August 10, 3:00 PM CST
Where
Cook County, 1.06 mi NE of Lakeview
Measured
65 kt (75 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.951, -87.645

Roofing material was peeled off a roof just north of Waveland Avenue and just west of Lake Shore Drive with debris blown across Lake Shore Drive.

Thunderstorm Wind, Cook

When
August 10, 3:00 PM CST
Where
Cook County, 1.84 mi SSE of Edgewater
Measured
60 kt (69 mph) estimated gust
Reported by
Social Media
Coordinates
41.965, -87.647

A tree was blown down blocking the exit from Lake Shore Drive to Wilson Drive.

Thunderstorm Wind, Kankakee

When
August 10, 3:01 PM CST to 3:02 PM CST
Where
Kankakee County, 0.39 mi WSW of Momence to 1.28 mi E of Momence
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.167, -87.677

Trees, tree limbs and power lines were blown down in Momence.

Thunderstorm Wind, Cook

When
August 10, 3:02 PM CST to 3:04 PM CST
Where
Cook County, 1.16 mi NNE of Skokie to 0.45 mi SE of Evanston
Measured
65 kt (75 mph) estimated gust
Reported by
Trained Spotter
Coordinates
42.046, -87.713

Numerous trees were snapped and uprooted in Evanston.

Thunderstorm Wind, Cook

When
August 10, 3:02 PM CST
Where
Cook County, 0.46 mi NW of Chicago Heights
Measured
55 kt (63 mph) estimated gust
Reported by
Public
Coordinates
41.505, -87.635

A 45 foot tall Pine tree was blown down in Chicago Heights.

Thunderstorm Wind, Cook

When
August 10, 3:02 PM CST
Where
Cook County, 2.09 mi SE of Edgewater
Measured
70 kt (81 mph) measured gust
Reported by
Mesonet
Coordinates
41.969, -87.631

Wind gusts to 80 mph were measured at the Montrose Harbor Light.

Thunderstorm Wind, Iroquois

When
August 10, 3:03 PM CST
Where
Iroquois County, 1.5 mi N of Papineau
Measured
57 kt (66 mph) measured gust
Reported by
Public
Coordinates
40.992, -87.722

A private weather station measured a wind gust to 66 mph.

Tornado, Kankakee

When
August 10, 3:04 PM CST to 3:06 PM CST
Where
Kankakee County, 1.15 mi NW of Grant Park to 0.84 mi NE of Grant Park
Rating
EF0
Path length
1.47 mi
Path width
150 yd
Reported by
NWS Storm Survey
Coordinates
41.243, -87.664

A tornado with peak winds of 80 mph touched down along N 11000 E Road. Tree limbs were blown down, a utility pole was damaged and crops were damaged. The tornado moved southeast through Grant Park. Numerous trees were damaged including some trees snapped and some trees uprooted. Minor roof damaged occurred to a house on Park Street and to another house on Maple Street. The tornado lifted near Lake Metonga.

Thunderstorm Wind, Kankakee

When
August 10, 3:04 PM CST to 3:05 PM CST
Where
Kankakee County, 0.67 mi WNW of St Anne to 0.63 mi ENE of St Anne
Measured
60 kt (69 mph) estimated gust
Reported by
Newspaper
Coordinates
41.024, -87.732

Tree limbs and power lines were blown down in St. Anne. The worst damage was outside the village, in St. Anne Township.

Thunderstorm Wind, Iroquois

When
August 10, 3:06 PM CST to 3:09 PM CST
Where
Iroquois County, 2.2 mi W of Watseka to 2.41 mi E of Watseka
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
40.782, -87.772

Trees, tree limbs and power lines were blown down across many areas in Iroquois County including in Watseka, where some of the worst damage was in Peters Park and Hubbard Park.

Thunderstorm Wind, Cook

When
August 10, 3:08 PM CST
Where
Cook County, 0.6 mi E of Thornton
Measured
52 kt (60 mph) estimated gust
Reported by
Trained Spotter
Coordinates
41.569, -87.609

Wind gusts were estimated to 60 mph in Thornton.

Thunderstorm Wind, Kankakee

When
August 10, 3:11 PM CST to 3:13 PM CST
Where
Kankakee County, 2.32 mi E of Wichert to 2.5 mi ESE of Hopkins Park
Measured
65 kt (75 mph) estimated gust
Reported by
Newspaper
Coordinates
41.054, -87.656

Trees, tree limbs and power lines were blown down in Pembroke Township. Almost everyone lost power.

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

EventDateAgeSexWhereKind
Thunderstorm Wind, Cook2020-08-1159MaleOutside/Open AreasIndirect

What these are

Thunderstorm Wind
Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Tornado
A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.
Hail
Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Funnel Cloud
A rotating column of cloud extending from a thunderstorm that did not reach the ground.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Illinois in 2020Every state in 2020This day in weather historyThe tornado archive for Illinois, 2020Warnings in Illinois, August 2020

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 914177, 909652, 913059, 915832, 908923, 914506, 909654, 912915, 915242, 915244, 909655, 915246, 915243, 912916, 914496, 913065, 915250, 908918, 914396, 915259, 908917, 909656, 914464, 914850, 913108, 914845, 915247, 914523, 913081, 913261, 915898, 909657, 914522, 909658, 914517, 914521, 914488, 914840, 908920, 914843, and more.