Tornadoes · United States · Illinois · 2020

EF0 tornado, Sank Ridge to Birds, Illinois, May 23, 2020

From Sank Ridge to Birds, this EF0 tornado ran 6.3 miles across Kendall, Grundy and Will counties on May 23, 2020, touching down at 2:53 PM CDT and reaching 100 yards wide. It killed nobody and injured 1.

The rating scale

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

  1. EF065 to 85 mphthis tornado

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

  2. EF186 to 110 mph

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

  3. EF2111 to 135 mph

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

  4. EF3136 to 165 mph

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

  5. EF4166 to 200 mph

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

  6. EF5over 200 mph

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

  7. Unrated

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

The record

Rating
EF0
Date
May 23, 2020
Touchdown
2:53 PM CDT (19:53 UTC)
Lifted
3:07 PM CDT (20:07 UTC)
On the ground
14 minutes
Path length
6.3 miles (10.1 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
1
Counties
Kendall, Grundy and Will counties
Touchdown point
41.453, -88.327
Lift-off point
41.480, -88.210
Record number
2005231353-01

What the Weather Service recorded

Scattered severe thunderstorms moved across northern Illinois during the afternoon of May 23rd producing wind damage, localized flooding and three tornadoes. Several funnel clouds were also reported.

A tornado touched down near Interstate 80, about a mile west of the Minooka exit. The tornado blew over a car on Interstate 80, which resulted in one injury. The tornado then moved into southeast Kendall County.

A tornado touched down in northeast Grundy County and moved into southeast Kendall County. Two wooden utility poles were blown down along with a half dozen large trees and numerous large tree limbs. The tornado continued into western Will County.

A tornado touched down in northeast Grundy County, moved into southeast Kendall County and then into far western Will County. Numerous large tree limbs were blown down.

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

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

The county was under a tornado watch, issued at 17:33 UTC and running to 01:00 UTC.

Issued (UTC)ExpiredProductOffice
17:33 UTC01:00 UTCTornado WatchLOT
19:08 UTC20:15 UTCSevere Thunderstorm WarningLOT
19:39 UTC20:17 UTCSevere Thunderstorm WarningLOT

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

The forecast that day

The Storm Prediction Center had this point in a Enhanced Risk, with a 0.10 chance of a tornado within 25 miles. The outlook in force was issued at 16:29 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

7.9 hours before the tornado, 149 km from the path. May 23, 2020.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2020-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -90225, lifted condensation level 1178 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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 2020-05-23The 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 79 square meters per square second, 0 to 6 km bulk shear 37 knots.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
-90225 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1178 m above ground
0-6 km bulk shear
37 kt
0-1 km bulk shear
15 kt
0-1 km storm-relative helicity
79 m²/s²
0-3 km storm-relative helicity
166 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.2 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 00:00Z

4.1 hours after it, 149 km from the path. May 24, 2020.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2020-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 778 joules per kilogram, CIN -4, lifted condensation level 1426 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 2020-05-24The 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 106 square meters per square second, 0 to 6 km bulk shear 20 knots.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
778 J/kg
Mixed-layer CIN
-4 J/kg
Surface CAPE
1808 J/kg
Mixed-layer LCL
1426 m above ground
0-6 km bulk shear
20 kt
0-1 km bulk shear
18 kt
0-1 km storm-relative helicity
106 m²/s²
0-3 km storm-relative helicity
122 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8
0-3 km lapse rate
7.4 K/km

Open this sounding in Storm Lab

The radar

The Chicago radar (KLOT), 22 km away, was scanning. The volume nearest the touchdown began at 19:56 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
19:05 UTCTSTM WND DMG2 E OttawaLa Salle, ILSPOTTER REPORTED NICKEL SIZED HAIL AND DOWNED TREES ON THE EAST SIDE OF OTTAWA. TIME ESTIMATED BY RADAR.
19:15 UTCHAIL 0.88MarseillesLa Salle, IL.
19:15 UTCHAIL 0.88MarseillesLa Salle, IL
19:53 UTCTORNADO1 Nw MinookaKendall, ILTRAINED SPOTTER REPORTED A TORNADO LOOKING NORTH FROM I-80 AND RIDGE RD AND DAMAGE INDICATES THERE WAS A TORNADO. THIS BEGAN AROUND 2:53 P.M. AT 41.4535/-88.3269 (3 WNW OF MINOOKA) AND ENDED AT 41.4800/-88.2106 (2.5 S OF
20:02 UTCTORNADO1 Nw MinookaGrundy, ILTRAINED SPOTTER REPORTED A TORNADO LOOKING NORTH FROM I-80 AND RIDGE RD. BEFORE IT BECAME RAIN-WRAPPED.
20:02 UTCTORNADO1 Nw MinookaKendall, ILTRAINED SPOTTER REPORTED A TORNADO LOOKING NORTH FROM I-80 AND RIDGE RD. BEFORE IT BECAME RAIN-WRAPPED.
20:03 UTCTSTM WND DMG1 Ssw ShorewoodWill, ILTREES AND POWERLINES DOWN AT SEIL ROAD NEAR THE DUPAGE RIVER.
20:15 UTCTSTM WND DMG2 Sw Crest HillWill, ILSEVERAL REPORTS OF POWER LINES DOWN ALONG BLACK RD. AT THE INTERSECTIONS WITH N ANN ST. AND N LARKIN AVE. TIME ESTIMATED BY RADAR.
20:20 UTCTSTM WND DMG1 Nne RockdaleWill, ILREPORTED ALONG PARK DRIVE IN JOLIET. LARGE TREE LIMBS DOWN. TIME IS ESTIMATED.
20:20 UTCTSTM WND DMG1 Nnw RockdaleWill, ILNEAR LARKIN AND JEFFERSON. WIDESPREAD TREE DAMAGE, INCLUDING SOME HEALTHY TREES A FOOT OR TWO IN DIAMETER, BLOCKING MULTIPLE STREETS. BETWEEN 3:15 AND 3:25 PM CDT.
20:20 UTCTSTM WND DMGJolietWill, ILVIDEO AND PHOTO SHARED ON FACEBOOK OF AN ENTIRE ROOF BLOWN OFF ONTO JEFFERSON STREET A BUILDING NEAR THE JOLIET SLAMMERS BALL PARK. TIME ESTIMATED BASED ON RADAR.
20:47 UTCHAIL 1BuckinghamKankakee, IL.
20:47 UTCHAIL 1BuckinghamKankakee, IL
21:00 UTCFLASH FLOODJolietWill, ILNUMEROUS PHOTOS ON SOCIAL MEDIA SHOWING STREET FLOODING THROUGHOUT JOLIET.
21:25 UTCHAIL 12 W KankakeeKankakee, IL
22:00 UTCHEAVY RAIN 1.7LansingCook, IL1.70 INCHES OF RAINFALL OBSERVED BETWEEN 4:15 AND 5:00 PM. STORM TOTAL OF 2.15 INCHES.

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 May 23, 2020

13 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 2312:30 PM CDTEF1Johnson, IA7.050
May 2312:57 PM CDTEF1Cedar, IA6.930
May 231:20 PM CDTEF0Clinton, IA1.220
May 231:53 PM CDTEF0Jackson, IA1.420
May 231:54 PM CDTEF0Woodford, IL3.575$20,000
May 232:24 PM CDTUnratedJackson, IA0.010
May 232:29 PM CDTEF1Whiteside, IL12.330
May 234:18 PM CDTUnratedJo Daviess, IL0.520
May 234:30 PM CDTEF1Ogle, IL0.3100
May 236:06 PM CDTEF0Kane, IL3.250
May 236:14 PM CDTUnratedGarza, TX0.430
May 236:52 PM CDTEF0Benson, ND0.120
May 236:07 PM MDTUnratedSherman, KS1.150

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.