Tornadoes · United States · Illinois · 2004

F0 tornado, Pesotum to Philo, Illinois, April 20, 2004

From Pesotum to Philo, this F0 tornado ran 0.1 miles across Champaign County on April 20, 2004, touching down at 2:32 PM CDT and reaching 50 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
April 20, 2004
Touchdown
2:32 PM CDT (19:32 UTC)
Path length
0.1 miles (0.2 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Champaign County
Touchdown point
40.030, -88.100
Lift-off point
40.030, -88.100
Record number
825

What the Weather Service recorded

As the tornado crossed from Douglas County into Champaign County, 3 miles southwest of Pesotum, it destroyed a barn as well as several trees and power lines. The tornado lifted and dissipated 2 miles south southwest of Pesotum. No injuries were reported.

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

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

The warnings

2 minutes of warning. NWS ILX issued a tornado warning for this county at 19:30 UTC, 2 minutes before the tornado touched down, in force until 20:15 UTC.

Issued (UTC)ExpiredProductOffice
19:30 UTC20:15 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 General Thunderstorms Risk. The outlook in force was issued at 16:20 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

7.5 hours before the tornado, 45 km from the path. April 20, 2004.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2004-04-20Temperature 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 -77876, lifted condensation level 1297 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 2004-04-20The 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 111 square meters per square second, 0 to 6 km bulk shear 33 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
0 J/kg
Mixed-layer CIN
-77876 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1297 m above ground
0-6 km bulk shear
33 kt
0-1 km bulk shear
14 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
169 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.4 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 00:00Z

4.5 hours after it, 45 km from the path. April 21, 2004.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2004-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 118 joules per kilogram, CIN -27, lifted condensation level 1737 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 2004-04-21The 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 176 square meters per square second, 0 to 6 km bulk shear 40 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
118 J/kg
Mixed-layer CIN
-27 J/kg
Surface CAPE
586 J/kg
Mixed-layer LCL
1737 m above ground
0-6 km bulk shear
40 kt
0-1 km bulk shear
31 kt
0-1 km storm-relative helicity
176 m²/s²
0-3 km storm-relative helicity
261 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7
0-3 km lapse rate
7.6 K/km

Open this sounding in Storm Lab

What was reported nearby

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

Time (UTC)ReportWhereCountyRemark
19:00 UTCTORNADO3 Nw TuscolaDouglas, ILSAME TORNADO WITH MULTIPLE TOUCHDOWNS IN DOUGLAS AND CHAMPAIGN COUNTIES. INITIAL TOUCHDOWN AT THIS LOCATION...DAMAGED A HOUSE AND BARN...WITH A SECOND HOUSE DAMAGED...MACHINE SHED AND GARAGE DESTROYED. DEBRIS PATH OF 1 T
19:00 UTCTORNADO3 Nw TuscolaDouglas, ILSAME TORNADO WITH MULTIPLE TOUCHDOWNS IN DOUGLAS AND CHAMPAIGN COUNTIES. INITIAL TOUCHDOWN AT THIS LOCATION...DAMAGED A HOUSE AND BARN...WITH A SECOND HOUSE DAMAGED...MACHINE SHED AND GARAGE DESTROYED. DEBRIS PATH OF 1 T
19:10 UTCTORNADO2 Sw PesotumChampaign, ILTOUCHDOWN OF SAME TORNADO...BARN DAMAGED CONTAINING ANTIQUE TRACTORS.
19:10 UTCTORNADO2 Sw PesotumChampaign, ILTOUCHDOWN OF SAME TORNADO...BARN DAMAGED CONTAINING ANTIQUE TRACTORS.
19:32 UTCTORNADO3 Ne PhiloChampaign, ILTRAINED SPOTTER REPORTED A BRIEF TORNADO TOUCHDOWN AT THE INTERSECTION OF COUNTY ROADS 1900E AND 1100N. STARTING TO DISSIPATING NOW. SAME TORNADO...MULTIPLE TOUCHDOWNS.
19:32 UTCTORNADO3 Ne PhiloChampaign, ILTRAINED SPOTTER REPORTED A BRIEF TORNADO TOUCHDOWN AT THE INTERSECTION OF COUNTY ROADS 1900E AND 1100N. STARTING TO DISSIPATING NOW. SAME TORNADO...MULTIPLE TOUCHDOWNS.

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

This ground now

The live radar over the trackEvery 2004 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of April 20, 2004

31 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 202:00 PM CDTF1Douglas, IL3.950$70,000
April 205:05 PM CDTF1Stark, IL10.8440$260,000
April 205:15 PM ESTF1Clinton, IN3.850$250,000
April 205:40 PM CDTF0Knox, IL2.830
April 205:40 PM ESTF1Boone, IN2.0508$1.8 million
April 205:44 PM CDTF3Putnam, IL15.8880812$8.0 million
April 205:45 PM CDTF0Holt, NE0.220
April 205:45 PM ESTF0Boone, IN0.130$70,000
April 205:45 PM ESTF0Howard, IN0.250$500,000
April 206:00 PM ESTF1Howard, IN0.7751$3.0 million
April 206:07 PM CDTF0Holt, NE0.220
April 206:10 PM CDTF2LaSalle, IL9.0400
April 206:24 PM ESTF0Miami, IN1.050
April 206:33 PM CDTF1LaSalle, IL1.530
April 206:50 PM CDTF0LaSalle, IL2.020
April 206:52 PM CDTF0Ford, IL0.520
April 206:59 PM CDTF0Iroquois, IL5.020
April 207:08 PM CDTF0Creek, OK0.4200
April 207:08 PM CDTF1Clinton, IA1.3100$30,000
April 207:08 PM ESTF1Wabash, IN2.0150$70,000
April 207:10 PM CDTF0Grundy, IL2.020$80,000
April 207:18 PM CDTF2Kankakee, IL3.050
April 207:24 PM ESTF0Madison, IN0.250$180,000
April 207:25 PM ESTF0Huntington, IN3.550$30,000
April 207:26 PM ESTF0Grant, IN4.0100
April 207:31 PM ESTF0Grant, IN0.250
April 207:35 PM CDTF1Kankakee, IL6.075
April 207:40 PM ESTF0Huntington, IN6.0150
April 207:45 PM CDTF1Will, IL1.6250$5.0 million
April 208:03 PM CDTF0Kankakee, IL3.020
April 208:18 PM CDTF0Will, IL1.520

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.