Isolated severe thunderstorm cells formed explosively during the late afternoon hours. The storms rapidly intensified into destructive hailstorms, producing golf ball to baseball size hail for sustained periods of time. During the evening, damaging winds became the main hazard as a bowing line of storms moved east-southeast across the Mount Vernon area. The storms formed in an extremely unstable air mass south of an outflow boundary that was generated from earlier storms well to the north. Strong daytime heating and high dew points in the mid 70's yielded mixed-layer capes around 5000 j/kg. Wind shear was adequate for organized storm structures. Effective shear values averaged around 30 knots.

Hail in JACKSON, ILLINOIS
From 30-JUN-23 15:52:00 to 30-JUN-23 16:00:00 (CST-6)
Location: MAKANDA
Magnitude: 1.75 
Crop damage: 0.00K
Reported by: Public

Hail in JACKSON, ILLINOIS
From 30-JUN-23 16:40:00 to 30-JUN-23 16:40:00 (CST-6)
Location: CARBONDALE
Magnitude: 1.75 
Crop damage: 0.00K
Reported by: Public

Hail in UNION, ILLINOIS
From 30-JUN-23 16:20:00 to 30-JUN-23 16:25:00 (CST-6)
Location: ANNA
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in UNION, ILLINOIS
From 30-JUN-23 16:37:00 to 30-JUN-23 16:37:00 (CST-6)
Location: ANNA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

This storm is the same storm that produced golf ball size hail in Anna.

Hail in WILLIAMSON, ILLINOIS
From 30-JUN-23 16:31:00 to 30-JUN-23 16:35:00 (CST-6)
Location: WHITEASH
Magnitude: 2.75 
Crop damage: 0.00K
Reported by: Public

Baseball size hail accompanied this storm that had a history of damaging giant hail in the Marion area. The damaging hail swath continued northeast.

Hail in FRANKLIN, ILLINOIS
From 30-JUN-23 18:13:00 to 30-JUN-23 18:13:00 (CST-6)
Location: BENTON
Magnitude: 1.75 
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in PERRY, ILLINOIS
From 30-JUN-23 19:30:00 to 30-JUN-23 19:30:00 (CST-6)
Location: TAMAROA
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in JOHNSON, ILLINOIS
From 30-JUN-23 17:03:00 to 30-JUN-23 17:05:00 (CST-6)
Location: CYPRESS
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Quarter to golf ball size hail fell in southwest Johnson County.

Hail in HAMILTON, ILLINOIS
From 30-JUN-23 18:02:00 to 30-JUN-23 18:02:00 (CST-6)
Location: RURAL HILL
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Quarter-size hail fell in the southwest corner of Hamilton County.

Thunderstorm Wind in HAMILTON, ILLINOIS
From 30-JUN-23 19:53:00 to 30-JUN-23 19:56:00 (CST-6)
Location: DAHLGREN
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Power lines were down in Mcleansboro. A large tree was down on State Route 142 and County Road 200E near Dahlgren.

Hail in WILLIAMSON, ILLINOIS
From 30-JUN-23 16:19:00 to 30-JUN-23 16:31:00 (CST-6)
Location: CRAINVILLE
Magnitude: 3.00 
Property damage: 10.00M
Crop damage: 0.00K
Reported by: Emergency Manager

Giant hail occurred in a swath of Williamson County along Illinois Route 13. The swath of large hail began near the Marion/Williamson County airport, just east and southeast of Crainville. Hail slightly larger than baseballs pounded the area in the immediate vicinity of the Marion/Williamson County Regional Airport. Hail damage was reported to planes at the airport, including broken windows. Numerous vehicles were damaged by hail from quarter size to golf-ball size. Hail damage occurred at the baseball stadium near Interstate 57 at Route 13. There was major damage to multiple vehicles at a car dealership on Route 13 between the Marion airport and the downtown Marion area. The large hail swath continued into the north side of the city of Marion, where hail the size of golf balls occurred.

Thunderstorm Wind in JEFFERSON, ILLINOIS
From 30-JUN-23 19:25:00 to 30-JUN-23 19:39:00 (CST-6)
Location: MT VERNON
Magnitude: 61.00 MG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Multiple trees and power lines were down in the Mt. Vernon area. A tree fell on a mobile home and damaged the home. A large maple tree was snapped. A wind gust to 70 mph was measured on a personal weather station two miles west-southwest of Mt. Vernon.

Hail in FRANKLIN, ILLINOIS
From 30-JUN-23 17:31:00 to 30-JUN-23 17:31:00 (CST-6)
Location: WEST FRANKFORT
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in WILLIAMSON, ILLINOIS
From 30-JUN-23 16:35:00 to 30-JUN-23 16:44:00 (CST-6)
Location: JOHNSTON CITY
Magnitude: 2.75 
Crop damage: 0.00K
Reported by: Trained Spotter

The severe thunderstorm that produced a destructive swath of golf ball to baseball size hail in Marion continued northeast across northern Williamson County. Baseball size hail accompanied the storm as it tracked east-northeast across north central and northeast parts of the county. Vehicles were dented and windshields were cracked.