Unrated tornado, Chandlerville to Newmansville, Illinois, July 10, 2021

1. EF065 to 85 mph

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

2. EF186 to 110 mph

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

3. EF2111 to 135 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. EF3136 to 165 mph

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

5. EF4166 to 200 mph

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

6. EF5over 200 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. Unratedthis tornado

   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

Unrated

Date

July 10, 2021

Touchdown

3:16 PM CDT (20:16 UTC)

Lifted

3:17 PM CDT (20:17 UTC)

On the ground

1 minutes

Path length

0.1 miles (0.1 km)

Path width

10 yards (9 m)

Deaths

0

Injuries

0

County

Cass County

Touchdown point

39.973, -90.045

Lift-off point

39.974, -90.046

Record number

2107101416-01

10 damage points were recorded along this path by NWS ILX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 95 mph.

• Damage to bus barn roof and door, also the greenhouse roof at the Virginia High School.
• Crop damage in the field about a half mile southwest of Virginia.
• Trees down near the Cass County Courthouse.
• Damage to the porch of a house.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

A Mesoscale Convective Vortex (MCV) generated by prior convection across Kansas and Missouri tracked into west-central Illinois during the afternoon of July 10th. Despite minimal instability, the enhanced low-level vorticity created by this feature was enough to trigger several rotating thunderstorm cells across west-central Illinois. Five brief tornadoes touched down across portions of Schuyler, Cass, and Morgan counties...with minor damage reported. Meanwhile further south, flash flooding occurred across parts of Clay County as thunderstorms with torrential rainfall skirted well south of I-70 during the evening.

A tornado touched down about 3.5 miles south-southwest of Chandlerville at 2:44 PM CDT. The tornado tracked northeastward along Illinois Route 78 from Palmerton Road to Philadelphia Road causing heavy tree and agricultural damage. A barn was flattened east of Palmerton Road. The tornado dissipated 1.2 miles south of Chandlerville at 2:51 PM CDT.

A tornado briefly touched down near the intersection of Newmansville Road and Cox Creek Road about 5.1 miles northeast of Philadelphia at 3:16 PM CDT. The tornado dissipated by 3:17 PM CDT with no damage occurring.

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

31 minutes of warning. NWS ILX issued a tornado warning for this county at 19:45 UTC, 31 minutes before the tornado touched down, in force until 20:34 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 Marginal Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 20:10 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.

Jacksonville (IJX), 28 km from the path, in the two hours either side.

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

The Lincoln radar (KILX), 63 km away, was scanning. The volume nearest the touchdown began at 20:13 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.

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

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

The live radar over the trackEvery 2021 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

7 more were confirmed in the United States that day.

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.