Tornadoes · United States · Illinois · 2003

F0 tornado, Millington, Illinois, May 30, 2003

This F0 tornado ran 2.5 miles across Kendall and LaSalle counties on May 30, 2003, touching down at 7:35 PM CDT and reaching 100 yards wide. It killed nobody.

The rating scale

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

  1. F040 to 72 mphthis tornado

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

  2. F173 to 112 mph

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

  3. F2113 to 157 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. F3158 to 206 mph

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

  5. F4207 to 260 mph

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

  6. F5261 to 318 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
F0
Date
May 30, 2003
Touchdown
7:35 PM CDT (00:35 UTC)
Path length
2.5 miles (4.0 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
Counties
Kendall and LaSalle counties
Touchdown point
41.600, -88.650
Lift-off point
41.600, -88.580
Record number
982

What the Weather Service recorded

Several supercell thunderstorms moved across northern Illinois during the evening hours of May 30th. Several tornadoes formed with these supercells with the strongest tornadoes and most extensive damage across Joliet and Lockport in Will counties. In addition to the tornadoes, wind damage was also reported across the area. Trees were blown down in Silver Springs State Park west of Yorkville in Kendall county. Trees and power lines were reported down in Somonauk in Dekalb county. Several trees and power lines were blown down near Lake Holiday in far northwest La Salle county and windows were blown out of some mobile homes near the Lake Holiday area. Large trees and power lines were blown down from Plainfield to Joliet. One tree fell onto a house. A gust to 80 mph was reported between Central Ave and Cicero Ave near 53rd in Chicago. Trees were reported down in Manteno in Kankakee county. Tree limbs were blown down across parts of McHenry county. In Paxton in Ford county, high winds damaged a farm shed, causing the roof to fall onto a tractor. A large tree fell onto a van, causing significant damage and the roof of a grain bin was damaged.

A tornado touched down about 3 miles northwest of Millington in LaSalle county at 735 pm. The tornado crossed the LaSalle/Kendall county line at 838pm, about 2.5 miles north of Millington. The tornado continued east for about one mile and lifted about 3 miles north-northeast of Millington at Finnie Road near the Fox River. Total path length was about 2.5 miles.

A tornado touched down about 3.5 miles east-northeast of Millington. A tree was damaged at Hollenback Road and Route 71. A large tree was snapped at Walker Road and Helmar Road. A large farm building collapased just south of Walker Road and east of Lisbon Road. The tornado lifted about 5 miles south-southwest of Yorkville.

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

The warnings

21 minutes of warning. NWS LOT issued a tornado warning for this county at 00:14 UTC, 21 minutes before the tornado touched down, in force until 00:45 UTC.

Issued (UTC)ExpiredProductOffice
00:14 UTC00:45 UTCTornado WarningLOT
00:28 UTC01:15 UTCTornado WarningLOT
00:49 UTC01:00 UTCTornado WarningLOT

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

The forecast that day

The Storm Prediction Center had this point in a Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 20:38 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.

Davenport, (KDVN), 00:00Z

0.6 hours before the tornado, 157 km from the path. May 31, 2003.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2003-05-31Temperature 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 -64895, lifted condensation level 3321 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Davenport, at 00:00Z on 2003-05-31The 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 -43 square meters per square second, 0 to 6 km bulk shear 56 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
-64895 J/kg
Surface CAPE
2391 J/kg
Mixed-layer LCL
3321 m above ground
0-6 km bulk shear
56 kt
0-1 km bulk shear
22 kt
0-1 km storm-relative helicity
-43 m²/s²
0-3 km storm-relative helicity
51 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.4
0-3 km lapse rate
9.0 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 12:00Z

11.4 hours after it, 157 km from the path. May 31, 2003.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2003-05-31Temperature 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 -78825, lifted condensation level 632 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Davenport, at 12:00Z on 2003-05-31The 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 -37 square meters per square second, 0 to 6 km bulk shear 57 knots.1939587897117136Sfc1 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
-78825 J/kg
Surface CAPE
2 J/kg
Mixed-layer LCL
632 m above ground
0-6 km bulk shear
57 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

The surface observations

Chicago/Aurora (ARR), 22 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
22:53 UTC7356180° 11 kt19997.6
23:53 UTC7059180° 12 kt995.6-RA
00:36 UTC64.462.6160° 7 kt995.3+RA BR
00:46 UTC64.460.8190° 8 kt17996.3+RA FG
00:53 UTC6461160° 3 kt16995.6-RA BR
00:57 UTC62.662.6160° 7 kt995.3-RA BR
01:04 UTC62.660.8160° 3 kt994.9
01:11 UTC62.660.8170° 5 kt994.9
01:53 UTC6361 6 kt16995.3

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

The radar

The Chicago radar (KLOT), 44 km away, was scanning. The volume nearest the touchdown began at 00:33 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.

This ground now

The live radar over the trackEvery 2003 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of May 30, 2003

20 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 305:25 PM CDTF0Dane, WI3.125
May 305:52 PM CDTF1Green, WI10.1100
May 306:25 PM CDTF0Winnebago, IL0.3100
May 306:33 PM CDTF0Winnebago, IL4.0100
May 306:36 PM CDTF0Lee, IL4.0100
May 307:16 PM CDTF0LaSalle, IL0.550
May 307:36 PM CDTF0Fulton, IL0.110
May 307:42 PM CDTF0Kendall, IL3.5100
May 307:53 PM CDTF2Woodford, IL7.3150
May 307:56 PM CDTF1Mason, IL14.0100
May 308:20 PM CDTF1Will, IL1.7100
May 308:22 PM CDTF0Logan, IL5.050
May 308:25 PM CDTF1Will, IL5.7100$60,000
May 308:30 PM CDTF0Cook, IL0.350
May 308:31 PM CDTF0Will, IL0.550
May 308:34 PM CDTF0Logan, IL0.110
May 308:34 PM CDTF0Kankakee, IL2.550
May 308:38 PM CDTF2Logan, IL14.0880$2.5 million
May 308:51 PM CDTF2DeWitt, IL12.81,1004$9.3 million
May 309:13 PM CDTF0Lake, IN0.350

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.