EF1 tornado, Limestone to Ahern, Illinois, July 28, 2023

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 mphthis tornado

   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. 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

EF1

Date

July 28, 2023

Touchdown

11:30 PM CDT (04:30 UTC)

Lifted

11:36 PM CDT (04:36 UTC)

On the ground

6 minutes

Path length

5.5 miles (8.9 km)

Path width

90 yards (82 m)

Deaths

0

Injuries

0

County

Kankakee County

Touchdown point

41.155, -87.722

Lift-off point

41.156, -87.617

Record number

2307282230-01

123 damage points were recorded along this path by NWS LOT, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 110 mph.

• numerous large branches downed onto house
• numerous trees with large branches downed, some trunks snapped. Metal sign damaged.
• trees uprooted, several branches downed, narrow corridor
• No structural damage noted

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

July 28th saw two rounds of severe storms move across the Chicago metro, one during the predawn hours of the morning and another during the evening. The first round brought isolated instances of damaging wind to the area and the second featured damaging winds, severe hail, and 13 tornadoes across the WFO Chicago CWA: 11 in Illinois and 2 in Indiana. Additionally, temperatures in the 90s and high humidity resulted in oppressively hot conditions with afternoon heat indices as high as 105-115��F.

This tornado began in the area of the River Bend neighborhood south of Route 113 and west of Kankakee, where multiple trees were uprooted or had large limbs snapped. The tornado appeared to cross Route 113 near the First Baptist Church and produced concentrated tree damage along Springview Drive. It then moved east into Bradley and Kankakee, where sporadic tree damage was observed into the Pioneer Park area. The tree damage again became more significant as the tornado moved toward Hammes Avenue, especially north of Spruce Street, where numerous trees were uprooted or had limbs snapped. In the area beyond this point to the east of I-57, there was no additional damage observed, but that area is much less developed compared to areas west of the interstate. Along this entire route, little to no structural damage was observed, though the Valspar facility along Fair Street had a partial collapse of one wall. The storm lifted just after crossing I-57 near Green Street. South of the track, sporadic straight-line wind damage was observed.

This tornado began just west of 8000 East Road at 2500 North Road west of Momence, based upon drone imagery provided by the Kankakee County Emergency Management Agency. The tornado produced EF-0 damage to a farm near the aforementioned intersection with damage to tree branches and part of a metal outbuilding roof damaged. The tornado continued east just south of 2500 North Road with a narrow, convergent path evident in a corn field from drone imagery. The tornado's intensity briefly weakened in the immediate vicinity of the Kankakee River with only limited tree damage noted. Just east of River South Road, the tornado again intensified as it moved through fields toward IL-17. Drone footage again indicated a narrow path of convergent damage in corn fields until the tornado moved into the backyards of a few residences on River South Road, causing significant damage to multiple trees. As the tornado moved east, drone footage revealed additional corn flattened in the field southwest of the Van Drunen Farms building. The tornado then struck a row of two-story apartment homes on Harvard Street, removing the roof and a portion of the upper-level walls from one of them and depositing the debris over the next couple of blocks to the east. Damage to the adjacent apartment homes was very minor. East of Harvard Street, there was little to no additional structural damage, but there was considerable damage to trees and power lines, especially along Indiana Street. East of Momence, the tornado continued along Route 114. Just west of N 13250E Road, it removed part of the roof of a metal outbuilding while snapping and uprooting additional trees. Little to no additional tornado damage was observed east of the intersection of Route 114 and N 13250E Road.

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

6 minutes of warning. NWS LOT issued a tornado warning for this county at 04:24 UTC, 6 minutes before the tornado touched down, in force until 04:45 UTC.

The county was under a severe thunderstorm watch, issued at 00:31 UTC and running to 05:44 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 Enhanced Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:53 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), 61 km away, was scanning. The volume nearest the touchdown began at 04:26 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 2023 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

16 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.