Tornadoes · United States · Illinois · 2000

F0 tornado, Le Roy, Illinois, May 18, 2000

This F0 tornado ran 0.1 miles across McLean County on May 18, 2000, touching down at 7:25 PM CDT and reaching 20 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 18, 2000
Touchdown
7:25 PM CDT (00:25 UTC)
Path length
0.1 miles (0.2 km)
Path width
20 yards (18 m)
Deaths
0
Injuries
0
County
McLean County
Touchdown point
40.350, -88.780
Lift-off point
40.350, -88.780
Record number
933

What the Weather Service recorded

A tornado briefly touched down in a field. No injuries or damage were reported.

Another tornado touched down in a field 1 mile west of LeRoy. No injuries or damage were reported.

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

The warnings

48 minutes of warning. NWS ILX issued a tornado warning for this county at 23:37 UTC, 48 minutes before the tornado touched down, in force until 00:45 UTC.

Issued (UTC)ExpiredProductOffice
22:43 UTC23:45 UTCSevere Thunderstorm WarningILX
22:56 UTC23:45 UTCTornado WarningILX
23:37 UTC00:45 UTCTornado WarningILX

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. The outlook in force was issued at 19:52 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), 00:00Z

0.4 hours before the tornado, 27 km from the path. May 19, 2000.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2000-05-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1192 joules per kilogram, CIN -15, lifted condensation level 1231 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 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, Lincoln, IL at 00:00Z on 2000-05-19The 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 218 square meters per square second, 0 to 6 km bulk shear 53 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
1192 J/kg
Mixed-layer CIN
-15 J/kg
Surface CAPE
1558 J/kg
Mixed-layer LCL
1231 m above ground
0-6 km bulk shear
53 kt
0-1 km bulk shear
35 kt
0-1 km storm-relative helicity
218 m²/s²
0-3 km storm-relative helicity
249 m²/s²
Significant tornado parameter
1.3
Supercell composite
3.2
0-3 km lapse rate
6.9 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 12:00Z

11.6 hours after it, 27 km from the path. May 19, 2000.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2000-05-19Temperature 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 -81464, lifted condensation level 601 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, Lincoln, IL at 12:00Z on 2000-05-19The 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 -62 square meters per square second, 0 to 6 km bulk shear 33 knots.1939587897117Sfc1 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
-81464 J/kg
Surface CAPE
6 J/kg
Mixed-layer LCL
601 m above ground
0-6 km bulk shear
33 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
-62 m²/s²
0-3 km storm-relative helicity
13 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
2.5 K/km

Open this sounding in Storm Lab

The surface observations

Bloomington/Norm (BMI), 18 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
22:45 UTC7764.4200° 24 kt401004.1BL DU
23:45 UTC62.660.8300° 16 kt1006.4-RA
00:45 UTC64.460.8300° 10 kt1008.8
01:45 UTC60.860.8330° 10 kt1010.2
02:00 UTC5959350° 14 kt1010.5BR

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

This ground now

The live radar over the trackEvery 2000 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of May 18, 2000

36 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 1810:20 AM CDTF0Adair, IA0.220
May 1810:31 AM CDTF0Adair, IA0.120$1,000
May 1810:33 AM CDTF0Adair, IA0.120$1,000
May 1810:58 AM CDTF0Cass, IA1.030$1,000
May 1812:01 PM CDTF1Warren, IA2.030$10,000
May 1812:17 PM CDTF0Polk, IA0.220$1,000
May 181:45 PM CDTF0Poweshiek, IA3.610$1,000
May 182:12 PM CDTF0Iowa, IA0.110
May 182:20 PM CDTF0Iowa, IA0.110
May 182:50 PM CDTF0Henry, IL0.110
May 183:09 PM CDTF0Henry, IL0.110
May 183:11 PM CDTF0Henry, IL0.110
May 183:34 PM CDTF0Henry, IL0.110
May 183:50 PM CDTF0Bureau, IL0.110$10,000
May 184:00 PM CDTF0Bureau, IL0.110$10,000
May 185:25 PM EDTF2Ulster, NY0.250$50,000
May 185:30 PM EDTF0Dutchess, NY0.120$70,000
May 184:42 PM CDTF1Boone, AR2.030
May 185:05 PM CDTF0LaSalle, IL3.0100
May 185:18 PM CDTF0Woodford, IL0.2201$10,000
May 185:35 PM CDTF0Livingston, IL0.550
May 185:50 PM CDTF0Livingston, IL0.550
May 186:00 PM CDTF0Livingston, IL0.550
May 186:10 PM CDTF0Kankakee, IL0.550
May 186:10 PM CDTF0Kankakee, IL0.550
May 186:45 PM CDTF0Livingston, IL0.550
May 187:05 PM CDTF0Newton, IN0.550
May 187:10 PM CDTF0Ford, IL0.550
May 187:12 PM CDTF0Porter, IN0.550
May 187:12 PM CDTF0Logan, IL2.520
May 187:13 PM CDTF0McLean, IL0.120
May 187:20 PM CDTF0Iroquois, IL0.550
May 187:30 PM CDTF0Ford, IL0.550
May 187:40 PM CDTF0Ford, IL0.550
May 187:45 PM CDTF0Champaign, IL0.110
May 188:00 PM CDTF0Iron, MO0.550$3,000

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.