F0 tornado, Dwight to Cullom, Illinois, May 30, 2004

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.

Rating

F0

Date

May 30, 2004

Touchdown

6:40 PM CDT (23:40 UTC)

Path length

1.0 miles (1.6 km)

Path width

20 yards (18 m)

Deaths

0

Injuries

0

County

Livingston County

Touchdown point

40.880, -88.330

Lift-off point

40.880, -88.320

Record number

963

The morning of May 30 started out with a line of showers and thunderstorms moving into north-central Illinois. Other thunderstorms developed over portions of east central Illinois and northwest Indiana. The major threat was heavy rain which produced widespread street flooding. There were also reports of thunderstorm wind damage. The line of thunderstorms continued to march east through northeast Illinois and northwest Indiana and by early afternoon the line had pushed east of the region. By mid afternoon a second line of thunderstorms crossed the Mississippi river into western Illinois and other storms developed over east central Illinois and northwest Indiana. The storms continued to move through the area into early evening. The two lines of thunderstorms produced widespread tree damage. There were also a few reports of lightning damage associated with these storms. Flash flooding was a serious problem as a considerable amount of rain had fallen recently in addition to heavy rains associated with these storms. The storms produced several weak tornadoes over Livingston County Illinois.

An experienced storm spotter and chaser reported a tornado 6 miles southwest of Dwight. Trees were damaged in this area. It had a brief narrow path.

A trained spotter reported and photographed a tornado west of Saunemin. Trees were knocked down on the north side of State Road 116 near 2500 East, about 3 miles west of Saunemin.

A brief, narrow tornado occurred along a 1 mile path on County Road 1700 North, from County Road 3100 East to about 3200 East. This is about 3.5 to 2.5 miles west of Cullom. There was minor damage to trees and a farm building.

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

9 minutes of warning. NWS LOT issued a tornado warning for this county at 23:31 UTC, 9 minutes before the tornado touched down, in force until 00:30 UTC.

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 Storm Prediction Center had this point in a High Risk, with a 0.25 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 16:38 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 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.

The Chicago radar (KLOT), 83 km away, was scanning. The volume nearest the touchdown began at 23:41 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.

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

80 more were confirmed in the United States that day.

All 81 of them

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.