EF1 tornado, Harmony to Barrington Hills, Illinois, July 12, 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 12, 2023

Touchdown

6:06 PM CDT (23:06 UTC)

Lifted

6:17 PM CDT (23:17 UTC)

On the ground

11 minutes

Path length

6.4 miles (10.3 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

County

McHenry County

Touchdown point

42.154, -88.519

Lift-off point

42.163, -88.394

Record number

2307121706-01

62 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 100 mph.

• Outer edge of leaf debris, twigs
• Approximate start point, per EM drone footage
• Damage to garage doors, siding, roofs
• Damage to siding, soffits, garages

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

During the evening of July 12, scattered thunderstorms dropped 13 tornadoes across far northeast Illinois, primarily within the west of northwest suburbs of Chicago. Of these 13 tornadoes, three were determined to be EF-1 with the remaining 10 being EF-0.

This tornado started in a field off US-20 near Getty Road along the McHenry/Kane County line. The tornado tracked east-northeast along and just south of Harmony Road, west of Huntley, snapping tree limbs and uprooting trees. The tornado continued east, just south of Main Street, damaging a small outbuilding and downing additional tree limbs. The tornado then shifted northeast into downtown Huntley while increasing to EF-1 intensity. It then continued between Main Street and Douglas Avenue causing substantial roof damage to two homes and uprooting additional trees. The tornado shifted a final time to the east-southeast, passing the Huntley Police station and causing more tree damage before lifting near Leland Lane and Central Park Boulevard on the east side of Huntley.

An EF-0 tornado began along Spring Creek Road in far southeastern McHenry County and the village of Barrington Hills before quickly moving into southwestern Lake County. Damage occurred as a farm outbuilding was struck, detaching two walls. Damage then continued with snapped trees and tree limbs along N Buckley Road and in the Chicago Highlands subdivision off of Northwest Highway. The tornado appeared to lift near W Sunset Road off IL-59, north of the Roslyn Road Elementary School in unincorporated Barrington.

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

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

The county was under a tornado watch, issued at 20:53 UTC and running to 23:51 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 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 20:00 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.

De Kalb (DKB), 32 km from the path, in the two hours either side.

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

The Chicago radar (KLOT), 69 km away, was scanning. The volume nearest the touchdown began at 23:05 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

23 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.