Tornadoes · United States · Illinois · 2020
EF1 tornado, DuPage County, Illinois, August 10, 2020
This EF1 tornado ran 0.4 miles across DuPage County on August 10, 2020, touching down at 3:35 PM CDT and reaching 100 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.
EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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
- EF1
- Date
- August 10, 2020
- Touchdown
- 3:35 PM CDT (20:35 UTC)
- Lifted
- 3:36 PM CDT (20:36 UTC)
- On the ground
- 1 minutes
- Path length
- 0.4 miles (0.6 km)
- Path width
- 100 yards (91 m)
- Deaths
- 0
- Injuries
- 0
- County
- DuPage County
- Touchdown point
- 41.867, -88.104
- Lift-off point
- 41.868, -88.097
- Record number
- 2008101435-01
The damage survey
13 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.
- Toppling of cupola/belltown/steeple of the College Church at Wheaton College.
Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.
The warnings
9 minutes of warning. NWS LOT issued a tornado warning for this county at 20:26 UTC, 9 minutes before the tornado touched down, in force until 21:00 UTC.
The county was under a severe thunderstorm watch, issued at 16:28 UTC and running to 22:23 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 16:28 UTC | 22:23 UTC | Severe Thunderstorm Watch | LOT |
| 19:56 UTC | 20:45 UTC | Severe Thunderstorm Warning | LOT |
| 20:26 UTC | 21:00 UTC | Tornado Warning | LOT |
| 20:32 UTC | 21:15 UTC | Severe Thunderstorm Warning | LOT |
| 20:43 UTC | 20:54 UTC | Tornado Warning | LOT |
| 21:23 UTC | 22:53 UTC | High Wind Warning | LOT |
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 Moderate Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:38 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.
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), 12:00Z
8.6 hours before the tornado, 196 km from the path. August 10, 2020.
- Mixed-layer CAPE
- 1597 J/kg
- Mixed-layer CIN
- -128 J/kg
- Surface CAPE
- 962 J/kg
- Mixed-layer LCL
- 1046 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 167 m²/s²
- 0-3 km storm-relative helicity
- 241 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.6
- 0-3 km lapse rate
- 3.8 K/km
Lincoln, IL (KILX), 00:00Z
3.4 hours after it, 196 km from the path. August 11, 2020.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -75157 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 1523 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- -307 m²/s²
- 0-3 km storm-relative helicity
- -226 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 4.2 K/km
The surface observations
Chicago/Dupage (DPA), 13 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 18:52 UTC | 87 | 74 | 170° 9 kt | 1010.5 | ||
| 19:52 UTC | 86 | 74 | 190° 10 kt | 1009.8 | ||
| 20:24 UTC | 86 | 74 | 210° 13 kt | 20 | 1010.5 | VCTS |
| 20:38 UTC | 68 | 65 | 250° 20 kt | 54 | 1012.9 | +TSRA |
| 20:49 UTC | 68 | 66.2 | 260° 18 kt | 29 | 1012.2 | TSRA |
| 20:52 UTC | 69 | 66 | 270° 23 kt | 33 | 1012.9 | -TSRA BR |
| 21:08 UTC | 70 | 66 | 280° 31 kt | 52 | 1012.9 | VCTS RA BR |
| 21:26 UTC | 70 | 65 | 290° 25 kt | 43 | 1013.9 | TSRA |
| 21:52 UTC | 70 | 65 | 320° 19 kt | 34 | 1012.9 | -TSRA |
| 22:00 UTC | 70 | 64 | 310° 12 kt | 26 | 1012.5 | -RA |
| 22:11 UTC | 70 | 64 | 310° 5 kt | 18 | 1011.9 | VCTS -RA |
| 22:26 UTC | 71 | 65 | 90° 7 kt | 1009.8 | -RA |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Chicago radar (KLOT), 29 km away, was scanning. The volume nearest the touchdown began at 20:36 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) | Report | Where | County | Remark |
|---|---|---|---|---|
| 19:59 UTC | TSTM WND GST 90 | Somonauk | De Kalb, IL | AN NWS DAMAGE SURVEY FOUND WIDESPREAD TREE DAMAGE WITH A FEW TREES SNAPPED VERY NEAR THEIR BASE. SEVEN LARGE AND NEW UTILITY POLES WERE ALSO SNAPPED ABOUT 10 FEET UP FROM THEIR BASE THREE MILES NORTH OF SOMONAUK. THE DAM |
| 20:05 UTC | TSTM WND DMG | Dekalb | De Kalb, IL | MULTIPLE TREES AND POWER LINES DOWN. ESTIMATED 60 MPH GUSTS. |
| 20:05 UTC | TORNADO | 3 S Marengo | Mchenry, IL | AN EF-1 TORNADO WITH PEAK WINDS OF 95 MPH AND PATH LENGTH OF 5.7 MILES TOUCHED DOWN ON HARMONY ROAD SOUTHWEST OF I-90 AND CONTINUED NORTHEAST BEFORE LIFTING NEAR DUNHAM ROAD BETWEEN MARENGO AND UNION. MOST DAMAGE WAS CON |
| 20:10 UTC | TSTM WND DMG | Maple Park | Kane, IL | MULTIPLE TREES AND POWER LINES DOWN, INCLUDING 10 AND 20 INCH IN DIAMETER TREES. FENCES ALSO BLOWN DOWN. TIME ESTIMATED BY RADAR. |
| 20:12 UTC | TORNADO | 3 Ssw Virgil | Kane, IL | DRONE FOOTAGE REVEALS A NARROW SWATH OF CORN LIKELY AROUND 40 YARDS ACROSS FLATTENED IN A CONVERGENT PATTERN. IN ADDITION, DAMAGE TO A BARN WAS NOTED, WITH A NEAR COMPLETE REMOVAL OF THE ROOF. THIS DAMAGE IS CONSISTENT W |
| 20:14 UTC | TSTM WND GST 57 | 2 Ese Somonauk | La Salle, IL | PRIVATE WEATHER STATION OBSERVED 57 MPH WIND GUST NEAR LAKE HOLIDAY. WIND GUSTS OVER 50 MPH FOR AT LEAST 15 MINUTES. |
| 20:14 UTC | TSTM WND GST 65 | 3 Sse Plano | Kendall, IL | PRIVATE WEATHER STATION RECORDED 65 MPH WIND GUST. |
| 20:15 UTC | TSTM WND DMG | 3 E Kaneville | Kane, IL | 8 INCH DIAMETER TREE SNAPPED NEAR IL-47 AND NOTTINGHAM. RELAYED VIA NWS CHAT, TIME ESTIMATED BY RADAR. |
| 20:15 UTC | TSTM WND DMG | 3 Ese Maple Park | Kane, IL | 4 INCH DIAMETER BRANCH DOWNED AND DAMAGE TO TRAFFIC SIGNALS AT IL-38 AND MEREDITH ROAD. TIME ESTIMATED BY RADAR. |
| 20:15 UTC | TSTM WND DMG | Somonauk | De Kalb, IL | TRAINED SPOTTER REPORTS WIDESPREAD TREE AND POWER LINE DAMAGE ACROSS SOMANAUK. TREES UP TO 4-6 DIAMETER SNAPPED AT THE BASE. |
| 20:15 UTC | TORNADO | 5 W Plainfield | Kendall, IL | AN EF-1 TORNADO WITH PEAK WINDS OF 105 MPH, PATH LENGTH OF 14.5 MILES, AND MAX WIDTH OF 250 YARDS STARTED ON THE SOUTH SIDE OF YORKVILLE DESTROYING A PERGOLA, TAKING SIDING OFF A HOUSE, AND THROWING A TREE ACROSS A ROAD. |
| 20:16 UTC | TSTM WND GST 62 | 1 Wnw Sugar Grove | Kane, IL | AURORA ASOS PEAK GUST. |
| 20:16 UTC | TSTM WND GST 62 | 2 W Sugar Grove | Kane, IL | |
| 20:20 UTC | TSTM WND DMG | 2 W Sugar Grove | Kane, IL | TREE DAMAGE BLOCKING FAYS LANE WEST OF SUGAR GROVE. TIME ESTIMATED BY RADAR. |
| 20:20 UTC | TSTM WND DMG | Aurora | Kane, IL | 10 INCH DIAMETER TREE SNAPPED. TIME ESTIMATED BY RADAR. |
| 20:20 UTC | TSTM WND DMG | Yorkville | Kendall, IL | SEVERAL TREES AND LARGE BRANCHES DOWN. TIME ESTIMATED BY RADAR. |
| 20:27 UTC | TSTM WND DMG | 1 Se Wayne | Dupage, IL | TREE DOWN ON ROAD NEAR NANCY LN AND POWIS RD IN WAYNE. |
| 20:29 UTC | TSTM WND DMG | St. Charles | Kane, IL | 14 INCH DIAMETER TREE SPLIT IN HALF. POWER LINES DOWNED. TIME ESTIMATED BY RADAR. |
| 20:30 UTC | TSTM WND DMG | 1 Wsw Crystal Lawns | Will, IL | 8-IN DIAMETER BRANCHES DOWN NEAR I-55 AND CATON FARM ROAD. RELAYED VIA AMATEUR RADIO. TIME ESTIMATED BY RADAR. |
| 20:30 UTC | TSTM WND DMG | 4 Nw Plainfield | Kendall, IL | DAMAGE TO SIDING OF A HOUSE. SMALL BRANCHES DOWNED IN THE VICINITY. TIME ESTIMATED BY RADAR. |
| 20:31 UTC | TSTM WND DMG | Plainfield | Will, IL | LARGE TREES AND POWER LINES DOWN ACROSS PLAINFIELD. TIME ESTIMATED BY RADAR. |
| 20:32 UTC | TSTM WND GST 84 | 2 N Plainfield | Will, IL | MEASURED BY WEATHERBUG STATION. |
| 20:33 UTC | TSTM WND DMG | 3 Nw Shorewood | Will, IL | PUBLIC REPORTS TREES DOWN NEAR CATON FARM ROAD AND DRAUDEN ROAD. |
| 20:34 UTC | TSTM WND DMG | Wheaton | Dupage, IL | SIX INCH DIAMETER TREE LIMB DOWN. TIME ESTIMATED BY RADAR. |
| 20:35 UTC | TSTM WND DMG | Warrenville | Dupage, IL | TRAINED SPOTTER REPORTS 1-6 IN DIAMETER TREE BRANCHES DOWN ALL OVER WARRENVILLE. |
| 20:35 UTC | TSTM WND GST 59 | 5 Se Lisbon | Grundy, IL | KC09 MORRIS AIRPORT. |
| 20:35 UTC | TORNADO | 1 Ene Wheaton | Dupage, IL | A VERY BRIEF TORNADO TOUCHED DOWN NEAR THE INTERSECTION OF SEMINARY AVENUE AND SCOTT STREET BEFORE MOVING NORTHEAST WHERE IT KNOCKED A ROUGHLY 50 FOOT STEEPLE AROUND TO THE NORTH SIDE OF THE COLLEGE CHURCH IN WHEATON. TH |
| 20:35 UTC | TORNADO | 1 Ene Wheaton | Dupage, IL | CORRECTS PREVIOUS TORNADO REPORT FROM 1 ENE WHEATON. A VERY BRIEF EF-1 TORNADO TOUCHED DOWN NEAR THE INTERSECTION OF SEMINARY AVENUE AND SCOTT STREET BEFORE MOVING NORTHEAST WHERE IT KNOCKED A ROUGHLY 50 FOOT STEEPLE ARO |
| 20:36 UTC | TSTM WND DMG | 2 W Streamwood | Cook, IL | ROLLED OVER B-CLASS TRUCK WITH TRAILER AT IRVING PARK ROAD AND SCHAUMBURG ROAD. |
| 20:36 UTC | TSTM WND DMG | Villa Park | Dupage, IL | 12 INCH DIAMETER TREE DOWN ON HOUSE. TIME ESTIMATED BY RADAR. |
| 20:36 UTC | TSTM WND DMG | Wheaton | Dupage, IL | STRUCTURAL DAMAGE TO THE ROOF OF WHEATON COLLEGE CHURCH. RELAYED VIA SOCIAL MEDIA. TIME ESTIMATED BY RADAR. |
| 20:36 UTC | TSTM WND GST 90 | Glen Ellyn | Dupage, IL | AN NWS DAMAGE SURVEY DETERMINED A CORRIDOR OF ENHANCED STRAIGHT LINE WINDS DAMAGED TREES AND UTILITY POLES WITH THE MOST CONCENTRATED DAMAGE EAST OF NORTH MAIN STREET TOWARD LAKE ELLYN PARK. DAMAGE IN THE REGION WAS CONS |
| 20:38 UTC | TSTM WND GST 62 | 1 Wsw Dupage Airport | Dupage, IL | DUPAGE ASOS PEAK GUST. |
| 20:38 UTC | TSTM WND GST 62 | Dupage Airport | Dupage, IL | KDPA WEST CHICAGO - DUPAGE ARPT. |
| 20:39 UTC | TSTM WND DMG | Bolingbrook | Will, IL | LARGE TREE LIMBS AND SMALL TREES DOWN. TIME ESTIMATED BY RADAR. |
| 20:39 UTC | TSTM WND GST 65 | Schaumburg | Cook, IL | ESTIMATED 60 TO 70 MPH WINDS. TIME ESTIMATED BY RADAR. |
| 20:39 UTC | TORNADO | 1 Nne Lombard | Dupage, IL | CORRECTS PREVIOUS TORNADO REPORT FROM 1 NNE LOMBARD. THE SAME STORM WHICH PRODUCED THE BRIEF WHEATON TORNADO PRODUCED ANOTHER REGION OF EF-1 TORNADO DAMAGE IMMEDIATELY EAST OF I-355 JUST EAST OF LILACIA PARK. THIS TORNAD |
| 20:39 UTC | TORNADO | 1 Nne Lombard | Dupage, IL | THE SAME STORM WHICH PRODUCED THE BRIEF WHEATON TORNADO PRODUCED ANOTHER REGION OF TORNADO DAMAGE IMMEDIATELY EAST OF I-355 JUST EAST OF LILACIA PARK. THIS TORNADO ALSO CONTINUED IN A NORTHEASTERLY DIRECTION, UPROOTING T |
| 20:40 UTC | TSTM WND DMG | 1 Ene Lakemoor | Lake, IL | 8-10 INCH DIAMETER LIMBS DOWNED IN THE VICINITY OF SULLIVAN LAKE ROAD AND GAME TRAIL. SOME BRANCHES WERE UP TO 20 FEET IN LENGTH. TIME ESTIMATED BY RADAR. |
| 20:40 UTC | TSTM WND DMG | 1 N Lombard | Dupage, IL | 4-5 BLOCK AREA OF WIDESPREAD TREE DAMAGE. 8 INCH AND LARGER DIAMETER BRANCHES BROKEN, SOME TREES SNAPPED NEAR THE TOP. RELAYED VIA AMATEUR RADIO. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2020 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are
The other tornadoes of August 10, 2020
26 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| August 10 | 11:30 AM CDT | Unrated | Marshall, IA | 1.0 | 50 | |||
| August 10 | 11:36 AM CDT | Unrated | Marshall, IA | 0.4 | 50 | |||
| August 10 | 11:39 AM CDT | EF1 | Marshall, IA | 2.9 | 100 | $20,000 | ||
| August 10 | 12:01 PM CDT | Unrated | Tama, IA | 1.5 | 40 | |||
| August 10 | 12:31 PM CDT | Unrated | Linn, IA | 0.9 | 40 | |||
| August 10 | 12:32 PM CDT | EF0 | Grant, WI | 0.6 | 50 | $15,000 | ||
| August 10 | 2:12 PM CDT | EF0 | Stephenson, IL | 4.6 | 50 | |||
| August 10 | 2:37 PM CDT | EF0 | Winnebago, IL | 1.6 | 50 | |||
| August 10 | 2:47 PM CDT | EF1 | Winnebago, IL | 9.2 | 300 | |||
| August 10 | 2:50 PM CDT | EF0 | DeKalb, IL | 6.3 | 40 | |||
| August 10 | 2:59 PM CDT | EF1 | LaSalle, IL | 0.9 | 150 | |||
| August 10 | 3:05 PM CDT | EF1 | McHenry, IL | 5.7 | 200 | |||
| August 10 | 3:12 PM CDT | EF1 | Kane, IL | 1.2 | 40 | |||
| August 10 | 3:15 PM CDT | EF1 | Kendall, IL | 14.4 | 250 | |||
| August 10 | 3:38 PM CDT | EF0 | Walworth, WI | 3.3 | 50 | $12,000 | ||
| August 10 | 3:39 PM CDT | EF1 | DuPage, IL | 2.1 | 200 | |||
| August 10 | 3:41 PM CDT | EF1 | Lake, IL to WI | 6.3 | 150 | $250,000 | ||
| August 10 | 3:54 PM CDT | EF1 | Cook, IL | 4.8 | 300 | |||
| August 10 | 3:57 PM CDT | EF0 | Cook, IL | 2.0 | 350 | |||
| August 10 | 3:59 PM CDT | EF1 | Cook, IL | 3.2 | 300 | |||
| August 10 | 4:04 PM CDT | EF0 | Kankakee, IL | 1.5 | 150 | |||
| August 10 | 5:05 PM EDT | EF1 | Washington, NY | 1.5 | 100 | $75,000 | ||
| August 10 | 4:15 PM CDT | EF0 | Newton, IN | 0.9 | 40 | |||
| August 10 | 6:32 PM EDT | EF1 | Saint Joseph, IN | 2.4 | 100 | |||
| August 10 | 6:55 PM EDT | EF1 | Kosciusko, IN | 3.1 | 100 | |||
| August 10 | 7:43 PM EDT | EF0 | Kosciusko, IN | 0.2 | 50 |
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.