Tornadoes · United States · Illinois · 2003

F1 tornado, Morton to Washington, Illinois, May 10, 2003

From Morton to Washington, this F1 tornado ran 1.5 miles across Tazewell County on May 10, 2003, touching down at 10:16 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 mph

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

  2. F173 to 112 mphthis tornado

    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
F1
Date
May 10, 2003
Touchdown
10:16 PM CDT (03:16 UTC)
Path length
1.5 miles (2.4 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
County
Tazewell County
Touchdown point
40.670, -89.450
Lift-off point
40.670, -89.420
Record number
885

What the Weather Service recorded

After the long track tornado dissipated, another tornado formed 3 miles north of Morton and traveled to the northeast. Three homes sustained major damage as well as a business. No injuries were reported.

A tornado first touched down in Tazewell County 3 miles southeast of Washington. It damaged a couple of homes and businesses, as well as blowing down numerous trees, power poles and power lines. The tornado then moved into Woodford County where it increased in intensity. No injuries were reported.

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

The warnings

31 minutes of warning. NWS ILX issued a tornado warning for this county at 02:45 UTC, 31 minutes before the tornado touched down, in force until 03:45 UTC.

Issued (UTC)ExpiredProductOffice
02:19 UTC03:15 UTCTornado WarningILX
02:45 UTC03:45 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 High Risk, with a 0.35 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 02:41 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

3.3 hours before the tornado, 91 km from the path. May 11, 2003.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2003-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2426 joules per kilogram, CIN -41, lifted condensation level 784 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 2003-05-11The 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 193 square meters per square second, 0 to 6 km bulk shear 58 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
2426 J/kg
Mixed-layer CIN
-41 J/kg
Surface CAPE
3687 J/kg
Mixed-layer LCL
784 m above ground
0-6 km bulk shear
58 kt
0-1 km bulk shear
21 kt
0-1 km storm-relative helicity
193 m²/s²
0-3 km storm-relative helicity
257 m²/s²
Significant tornado parameter
3.2
Supercell composite
17.1
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 12:00Z

8.7 hours after it, 91 km from the path. May 11, 2003.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2003-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 9 joules per kilogram, CIN -3, lifted condensation level 815 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 12:00Z on 2003-05-11The 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 -67 square meters per square second, 0 to 6 km bulk shear 90 knots.1939587897117136156Sfc1 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
9 J/kg
Mixed-layer CIN
-3 J/kg
Surface CAPE
21 J/kg
Mixed-layer LCL
815 m above ground
0-6 km bulk shear
90 kt
0-1 km bulk shear
23 kt
0-1 km storm-relative helicity
-67 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
4.6 K/km

Open this sounding in Storm Lab

The surface observations

Peoria (PIA), 21 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
01:54 UTC7372190° 12 kt25997.6-TSRA BR
01:59 UTC73.471.6210° 9 kt19997.3+TSRA BR
02:10 UTC71.671.6190° 7 kt997.6TSRA BR
02:15 UTC71.671.6200° 8 kt997.6TSRA BR
02:29 UTC71.671.6230° 5 kt998+TSRA BR
02:36 UTC71.671.60° 0 kt997.3+TSRA BR
02:43 UTC71.671.620° 10 kt995.9+TSRA BR
02:54 UTC7170220° 17 kt21997-TSRA BR
03:00 UTC71.669.8200° 12 kt997-TSRA
03:07 UTC71.669.8210° 14 kt997TS
03:15 UTC69.869.8210° 14 kt20997TS
03:54 UTC6968240° 16 kt22997-TSRA BR
04:36 UTC66.264.4260° 19 kt28997.3
04:54 UTC6559250° 19 kt26998

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

The radar

The Lincoln radar (KILX), 58 km away, was scanning. The volume nearest the touchdown began at 03:16 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 10, 2003

50 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 103:00 AM CDTF0Butler, KS4.0110$10,000
May 103:05 AM CDTF0Marion, KS6.0110$50,000
May 107:53 AM CDTF0Sangamon, IL0.110
May 107:55 AM CDTF0Sangamon, IL0.220
May 107:58 AM CDTF0Sangamon, IL1.030$40,000
May 108:08 AM CDTF0Christian, IL0.320
May 109:45 AM CDTF0Cumberland, IL0.110
May 1010:40 AM CDTF0Edgar, IL0.110
May 1010:51 AM ESTF0Putnam, IN0.550$10,000
May 1011:00 AM CDTF1Jasper, IL1.5100$10,000
May 104:45 PM EDTF3Mason, KY25.020017$5.5 million
May 104:02 PM CDTF0Linn, MO0.525
May 104:38 PM CDTF0Mercer, MO0.125$1,000
May 104:56 PM CDTF1Putnam, MO7.0100$20,000
May 105:23 PM CDTF0Macon, MO5.550$1,000
May 105:26 PM CDTF1Marion, IA18.550$320,000
May 105:33 PM CDTF2Knox, MO22.1200$500,000
May 105:35 PM CDTF0Putnam, MO0.550$1,000
May 105:50 PM CDTF0Shelby, MO5.050
May 106:08 PM CDTF2Lewis, MO20.02006$5.0 million
May 106:10 PM CDTF0Lewis, MO4.050
May 106:19 PM CDTF0Monroe, MO0.240
May 106:27 PM CDTF0Tama, IA0.125
May 106:28 PM CDTF2Lee, IA11.5200$1.0 million
May 106:30 PM CDTF0Marion, MO2.550
May 106:36 PM CDTF2Adams, IL69.23004$1.1 million
May 106:37 PM CDTF3Marion, MO12.0200
May 107:10 PM CDTF0Van Buren, IA4.0100$100,000
May 107:20 PM CDTF2Adams, IL30.8300
May 107:23 PM CDTF0Jefferson, IA5.0100$100,000
May 107:33 PM CDTF0Jefferson, IA2.4100$100,000
May 107:44 PM CDTF1Henry, IA27.9200$2.0 million
May 108:14 PM CDTF2Schuyler, IL6.0150
May 108:15 PM CDTF1Lafayette, WI7.82001$200,000
May 108:30 PM CDTF0Mercer, IL8.3100$100,000
May 108:32 PM CDTF1Fulton, IL3.0400
May 108:39 PM CDTF1Iowa, WI8.6200$300,000
May 109:42 PM EDTF0Beaufort, NC0.150
May 108:45 PM CDTF0Mercer, IL2.150$100,000
May 108:47 PM CDTF1Fulton, IL2.7100
May 108:55 PM CDTF0Mercer, IL3.850$50,000
May 108:55 PM CDTF0Henry, IL25.5100$650,000
May 109:12 PM CDTF1Mason, IL8.0150
May 109:33 PM CDTF2Mason, IL2.51001
May 109:38 PM CDTF1Mason, IL2.0100
May 109:45 PM CDTF3Tazewell, IL17.544032$10 million
May 109:58 PM CDTF0Bureau, IL4.150$50,000
May 1010:18 PM CDTF2Woodford, IL12.53004
May 1010:25 PM CDTF1Woodford, IL8.0200
May 1010:35 PM CDTF1Jackson, AR0.630

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.