Tornadoes · United States · Illinois · 2007

EF1 tornado, DuPage County, Illinois, August 23, 2007

This EF1 tornado ran 2.7 miles across DuPage County on August 23, 2007, touching down at 3:08 PM CDT and reaching 500 yards wide. It killed nobody, and did $15,000 of property damage.

The rating scale

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

  1. EF065 to 85 mph

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

  2. EF186 to 110 mphthis tornado

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

  3. EF2111 to 135 mph

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

  4. EF3136 to 165 mph

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

  5. EF4166 to 200 mph

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

  6. EF5over 200 mph

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

  7. Unrated

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

The record

Rating
EF1
Date
August 23, 2007
Touchdown
3:08 PM CDT (20:08 UTC)
Lifted
3:10 PM CDT (20:10 UTC)
On the ground
2 minutes
Path length
2.7 miles (4.3 km)
Path width
500 yards (457 m)
Deaths
0
Injuries
0
Property damage
$15,000
County
DuPage County
Touchdown point
41.870, -88.170
Lift-off point
41.870, -88.170
Record number
0708231408-01

The warnings

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

The county was under a severe thunderstorm watch, issued at 17:29 UTC and running to 00:12 UTC.

Issued (UTC)ExpiredProductOffice
03:06 UTC03:47 UTCSevere Thunderstorm WarningLOT
17:29 UTC00:12 UTCSevere Thunderstorm WatchLOT
19:00 UTC02:14 UTCFlash Flood WatchLOT
19:41 UTC20:45 UTCSevere Thunderstorm WarningLOT
20:13 UTC20:38 UTCTornado WarningLOT
22:04 UTC02:00 UTCFlash Flood WarningLOT
22:34 UTC23:28 UTCSevere Thunderstorm WarningLOT
02:20 UTC09:00 UTCFlash Flood WarningLOT

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

The forecast that day

The Storm Prediction Center had this point in a Moderate Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 20:01 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

8.1 hours before the tornado, 195 km from the path. August 23, 2007.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2007-08-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1293 joules per kilogram, CIN -91, lifted condensation level 1289 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Lincoln, IL at 12:00Z on 2007-08-23The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 88 square meters per square second, 0 to 6 km bulk shear 43 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
1293 J/kg
Mixed-layer CIN
-91 J/kg
Surface CAPE
54 J/kg
Mixed-layer LCL
1289 m above ground
0-6 km bulk shear
43 kt
0-1 km bulk shear
25 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
106 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.7
0-3 km lapse rate
3.5 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 00:00Z

3.9 hours after it, 195 km from the path. August 24, 2007.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2007-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 904 joules per kilogram, CIN -21, lifted condensation level 2022 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Lincoln, IL at 00:00Z on 2007-08-24The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 13 square meters per square second, 0 to 6 km bulk shear 15 knots.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
904 J/kg
Mixed-layer CIN
-21 J/kg
Surface CAPE
1558 J/kg
Mixed-layer LCL
2022 m above ground
0-6 km bulk shear
15 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
34 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.3 K/km

Open this sounding in Storm Lab

The surface observations

Chicago/Dupage (DPA), 8 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
18:52 UTC8774230° 12 kt221010.5
19:52 UTC8474180° 8 kt1009.5
20:07 UTC7769.8280° 29 kt581012.9-RA SQ
20:10 UTC71.668270° 24 kt581013.5+RA BR SQ
20:15 UTC69.868250° 19 kt361014.2+RA FG
20:30 UTC71.668300° 8 kt1011.9RA BR
20:32 UTC71.668310° 8 kt1011.5RA BR
20:52 UTC716810° 5 kt1010.5-RA
21:52 UTC7269150° 7 kt1010.5-RA

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

The radar

The Chicago radar (KLOT), 30 km away, was scanning. The volume nearest the touchdown began at 20:09 UTC.

Open the radar archive at this moment, over the track

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

What was reported nearby

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

Time (UTC)ReportWhereCountyRemark
19:24 UTCTSTM WND DMGBataviaKane, ILSIGNIFICANT TREE DAMAGE ACROSS BATAVIA AND FABYAN PARK PRESERVE
19:24 UTCTSTM WND GST 58Ohare AirportCook, IL50 KNOT GUST AT ORD ASOS
19:26 UTCTSTM WND DMGDe KalbDe Kalb, ILWIND ESTIMATED AT 50 TO 60 MPH. CORN BENT OVER.
19:30 UTCTSTM WND DMGDe KalbDe Kalb, ILPOWER POLES DOWN ON NORMAL STREET.
19:30 UTCTSTM WND GST 58MorrisGrundy, ILSHABONNA ROAD AND SOUTHMOR JUST SOUTH OF MORRIS
19:32 UTCTSTM WND GST 65WheatonDupage, IL
19:50 UTCTSTM WND DMGElburnKane, ILTREE DOWN ON FRANCIS ROAD
19:54 UTCTSTM WND DMGMorrisGrundy, ILSEVERAL 8 TO 10 INCH DIAMETER TREE LIMBS DOWN AND 30 FOOT SECTION OF CORN FIELD FLATTENED. SARATOGA ROAD 1 MILE NORTH OF INTERSTATE 80
19:55 UTCFUNNEL CLOUD4 W GenevaKane, ILROTATING WALL CLOUD 1 MILE SOUTH OF US 38
19:55 UTCFUNNEL CLOUDMaple ParkKane, ILROTATING WALL CLOUD AT US 38 AND KANE COUNTY LINE
19:55 UTCHEAVY RAIN 0.85GenevaKane, IL20 MINUTE RAINFALL MEASUREMENT
20:02 UTCFUNNEL CLOUDSugar GroveKane, ILAT INTERSTATE 88 AT SUGAR GROVE
20:02 UTCTSTM WND GST 62BataviaKane, ILFROM KANE COUNTY EOC
20:04 UTCTSTM WND GST 67West ChicagoDupage, ILDUPAGE COUNTY AIRPORT ASOS GUST
20:05 UTCFUNNEL CLOUDWest ChicagoDupage, ILROTATING WALL CLOUD
20:05 UTCTSTM WND DMG5 Sw PlainfieldKendall, ILLARGE TREE LIMB DOWN COUNTY LINE ROAD BETWEEN RENWICK AND CATON FARM ROAD. KENDALL COUNTY SIDE OF COUNTY LINE
20:05 UTCTSTM WND DMGWest ChicagoDupage, IL*** 7 INJ *** BUILDING COLLAPSE ON FENTON AVENUE
20:08 UTCTORNADOWinfieldDupage, ILBEGINNING OF TORNADO PATH AT PRINCE CROSSING ROAD SOUTH OF GENEVA ROAD. MOVED EAST NORTHEAST FOR APPROXIMATELY 1.5 MILES. ENDING OF TORNADO PATH NEAR GARY AVENUE.
20:10 UTCFUNNEL CLOUDSt. CharlesKane, ILROTATING WALL CLOUD IL RTE 64 AND TAYLOR
20:10 UTCTSTM WND DMGWinfieldDupage, ILDAMAGE TO LOADING DOCK AND PARKING GARAGE EAVES AT CENTRAL DUPAGE HOSPITAL
20:10 UTCTSTM WND GST 583 Se AuroraDupage, IL
20:10 UTCTSTM WND GST 58GenevaKane, IL
20:10 UTCTSTM WND GST 75ElginKane, IL
20:10 UTCHAIL 1GenevaKane, ILMAIN AND RANDALL ROADS
20:10 UTCNON-TSTM WND DMGWinfieldDupage, ILDAMAGE TO LOADING DOCK AND PARKING GARAGE EAVES AT CENTRAL DUPAGE HOSPITAL
20:14 UTCTSTM WND GST 67RomeovilleWill, ILMEASURED WFO CHICAGO
20:15 UTCTSTM WND DMGCrest HillWill, ILLARGE TREE DOWN AT SWEETBRIAR AVE AND GAYLORD ROAD
20:15 UTCTSTM WND DMGGenevaKane, ILEXTENSIVE TREE AND POWER LINE DAMAGE IN CITY OF GENEVA
20:15 UTCTSTM WND DMGJolietWill, ILNUMEROUS REPORTS OF TREES AND POLES DOWN ACROSS WEST END OF WILL COUNTY
20:15 UTCTSTM WND DMGWheatonDupage, ILTREES UPROOTED. ESTIMATED 90 MPH GUST AT DUPAGE COUNTY EOC GARY AVENUE AND JEWEL ROAD.
20:15 UTCTSTM WND DMGWinfieldDupage, ILA 50 FOOT DOUGLAS FIR TREE HAD TOP 25 FEET SHEARED OFF AND LANDED ON NEIGHBORS ROOF.
20:15 UTCTSTM WND GST 70StreamwoodCook, IL
20:15 UTCNON-TSTM WND DMGNew LenoxWill, ILLARGE TREES UPROOTED. ESTIMTED 75 MPH WINDS
20:20 UTCTSTM WND DMGMount ProspectCook, ILPOWER LINES DOWN DEMPSTER STREET SOUTH OF BUSSE ROAD
20:20 UTCTSTM WND DMGStreamwoodCook, ILLARGE TREES DOWN ALL OVER TOWN...SOME ON CARS AND HOUSES
20:21 UTCTSTM WND DMGDes PlainesCook, ILEXTENSIVE TREE DAMAGE CITY WIDE IN DES PLAINES
20:23 UTCTSTM WND GST 60Des PlainesCook, IL
20:23 UTCTSTM WND GST 68JolietWill, ILINTERSECTION OF ESSINGTON AND ANN
20:23 UTCTORNADOBolingbrookWill, ILROUTE 53 AND BOUGHTON ROAD
20:24 UTCFUNNEL CLOUDOrland ParkCook, ILROTATING WALL CLOUD

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

This ground now

The live radar over the trackEvery 2007 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of August 23, 2007

2 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 234:01 PM EDTEF1Montcalm, MI0.2200$150,000
August 237:07 PM EDTEF0Sanilac, MI0.525

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.