# July 15, 2024 Chicagoland tornado outbreak

The July 15, 2024 Chicagoland tornado outbreak was a tornado outbreak and severe weather event occurring in the Midwestern United States. This weather event broke the daily record for tornado touchdowns in the Chicagoland forecasting area, where approximately 33 tornados touched down in the Chicagoland area and other surrounding areas. The outbreak produced mostly weak EF0/EF1 tornados, though one EF2 tornado did drop down in the Channahon-Matteson area. The storm also produced intense straight line winds, most of which reached up to 80 mph and one reaching nearly 90 mph.

## Before the storm

The day before, the Storm Prediction Center issued an Enhanced Risk of Severe Weather, with a 30% Significant Severe Probability of Damaging Winds, a 5% Probability of a Tornado, and a 5% probability of large hail.
The next day, it was increased to a Moderate risk with a 45% probability of Damaging Winds and a 10% probability of a tornado.

## Storm development

In the evening hours of July 15, 2024, a complex system of thunderstorms moving across the northern Midwestern United States produced supercell thunderstorms and a derecho, a rare weather event. Derechos form when humid air and downdrafts collide to create bow echos, which are curved or bowed thunderstorms. These bow echos may eventually create a derecho, which are widespread and long-lasting powerful windstorms. The humid Midwest air mixing with an incoming cold front allowed a strong derecho to form, where supercell thunderstorms were quickly produced as a result. As the system moved east into Illinois, tornado watch alerts were issued in the late afternoon and early evening.

## General timeline

At 7:44 p.m., the first tornado warning was issued for Ogle County. This harmless tornado was an EF0 and a short lived seven-minute touchdown. By 8:00 p.m., two other EF0 tornados had dropped in Ogle County and Winnebago County. These first few tornados did relatively little damage and resulted in no fatalities.
For about a forty minute period, the storm moved slightly northeast but did not produce any tornados, until 8:38 p.m., when a tornado dropped in Kane and DeKalb Counties. From about 8:45 to 9:45 p.m., approximately 20 tornadoes and strong wind bursts were recorded in surrounding areas. Most of the recorded tornadoes were EF0 and EF1 ratings, with minimal roof and tree damage.
After 9:45 p.m., approximately six other tornadoes touched down as the storm approached Chicago, Illinois and Gary, Indiana. The final tornado dissipated at 10:20 p.m., near Valparaiso, Indiana. The storm took place over an approximate three hour timeline and the final tornado warnings were let up after 10:20 p.m., when it was confirmed that the system had passed completely.

### Channahon-Matteson EF2

The highest rated tornado was the Channahon-Matteson tornado, which was given an EF2 rating. The tornado lasted from 9:17 to 9:40 p.m. and moved on a 28.9-mile path through Will and Cook Counties. The maximum recorded wind speed of the tornado was about 120 mph and the maximum recorded width of the tornado was about 200 yards. The tornado resulted in two injures and was responsible for nearly five hours of traffic on Interstate 55, where drivers became trapped by debris and surrounded by unstable power lines which had fallen onto the highway. After the storm, ComEd teams worked to clear the debris, closing a nearly seven mile stretch of the road for three days. After three days, ComEd reported that nearly 18,000 residents of the area were still without power due to this tornado. Other damage included crop destruction, tree damage, and roof damage.

## Confirmed tornadoes

Enhanced Fujita Scale for reference :
| Rating | EFU | EF0 | EF1 | EF2 | EF3 | EF4 | EF5 |
| Description | Unknown | Weak | Moderate | Significant | Severe | Extreme | Catastrophic |
| Wind speed | Unknown | 65–85 MPH | 86–110 MPH | 111–135 MPH | 136–165 MPH | 166–200 MPH | 200+ MPH |
All confirmed tornadoes :
| Rating | Location | Time (CDT) | Path length | Damage |
| EF0 | Ogle County | 7:44 – 7:51 p.m. | 5.2 miles | Tornado touched down in Byron, producing minor tree damage and tearing the roof off of a car wash. |
| EF0 | Ogle County | 7:58 – 8:00 p.m. | 1.7 miles | Tornado produced minor tree damage on the north side of Davis Junction. |
| EF0 | Winnebago County | 7:58 – 7:59 p.m. | 1.1 miles | Tornado moved along Montague Road just southwest of Rockford, causing damage to corn crops, trees, and powerlines. |
| EFU | DeKalb and Kane Counties | 8:38 – 8:40 p.m. | 1.7 miles | Radar indicates that a circulating funnel briefly touched down, causing minor crop damage. |
| EF1 | Kane County | 8:49 – 9:00 p.m. | 8.4 miles | Damage unknown |
| EF0 | Kane County | 8:52 – 9:05 p.m. | 10.1 miles | Damage unknown |
| EF1 | Kendall and Will Counties | 8:55 – 9:18 p.m. | 19.1 miles | Tornado uprooted and snapped trees. Minor structural damage was also reported. |
| EF1 | Kendall and Will Counties | 9:07 – 9:26 p.m. | 16.3 miles | Damage unknown |
| EF0 | Kendall and Will Counties | 9:12 – 9:29 p.m. | 14.3 miles | Tornado produced extensive roof damage to Plainfield High School and St. John Lutheran Church. Minor tree damage was also noted before the tornado dissipated near I-355. |
| EF2 | Will and Cook Counties | 9:17 – 9:40 p.m. | 28.9 miles | See section on this tornado |
| EF0 | DuPage County | 9:23 – 9:27 p.m. | 3.1 miles | Tornado extensively damaged trees but produced minor roof and structural damage. |
| EF0 | DuPage County | 9:29 – 9:30 p.m. | 0.8 miles | A brief tornado touched down and produced tree damage as well as straight line wind damage. |
| EF0 | DuPage and Cook Counties | 9:34 – 9:42 p.m. | 3.8 miles | Tornado impacted O'Hare Airport, where windows, doors, and exterior paneling and roofing were destroyed. Tree damage was also reported. |
| EF0 | Kankakee County | 9:36 – 9:45 p.m. | 12.3 miles | Damage unknown |
| EF0 | Cook County | 9:36 – 9:37 p.m. | 0.8 miles | Tornado destroyed the roofs of three apartment buildings and produced tree damage which in turn caused vehicle damage as well. |
| EF1 | Cook County | 9:37 – 9:40 p.m. | 2.1 miles | Tornado produced extensive tree damage and caused structural to multiple houses. A greenhouse in the area was also destroyed. |
| EF0 | Cook County | 9:41 – 9:48 p.m. | 5.7 miles | Damage unknown |
| EF0 | Will County | 9:41 – 9:46 p.m. | 6.4 miles | Damage unknown |
| EF0 | Cook County | 9:43 – 9:44 p.m. | 0.4 miles | Damage unknown |
| EF1 | Cook County | 9:43 – 9:49 p.m. | 5.5 miles | Tornado passed through Thornton where it produced tree damage and minor structural damage. |
| EF0 | Cook County | 9:45 – 9:46 p.m. | 0.4 miles | Damage unknown |
| EF1 | City of Chicago and Cook County | 9:47 – 9:53 p.m. | 3.0 miles | Tornado uprooted numerous trees and caused roof damaged to a building near Stillman Park. Minor structural damage at the Chicago Police Academy building was also reported. |
| EF1 | City of Chicago and Cook County | 9:47 – 9:51 p.m. | 3.2 miles | Tornado snapped multiple large willow trees at their bases and produced a corridor of tree damage in Marquette Park. |
| EF0 | City of Chicago and Cook County | 9:50 – 9:52 p.m. | 1.4 miles | Tornado uprooted and downed large trees. Structural damage to buildings was reported, such as windows being blow out, damage to roofing, and damage to walls. |
| EF1 | Kankakee County | 9:51 – 9:53 p.m. | 2.6 miles | Damage unknown |
| EF1 | Lake and Porter Counties | 9:52 – 10:20 p.m. | 29.1 miles | Tornado hit Cedar Lake and Valparaiso, where extensive tree damage and damage to two houses was reported. One fatality was also reported, though it is unclear if this is due to the tornado or the storm's straight line winds. |
| EF0 | Lake and Jasper Counties | 10:02 – 10:14 p.m. | 13.7 miles | Tornado produced tree damage and roofing damage. |
The information listed above represents data that is known as of 2 August 2024. This data chart may eventually be inaccurate if new data emerges.
Some of the confirmed tornadoes listed above have unknown damage. This may mean that that specific tornado had little to no damage, unreported damage, or damage that has yet to be recorded/released.