A supercell thunderstorm organized over southern Jackson County, then spawned a tornado as it moved east along the Union/Williamson County line. This supercell continued east-southeast across northern Johnson and northern Pope Counties, producing two significant tornadoes and large hail. Although the storm exhibited strong rotation as it continued east through Hardin County and across the Ohio River into Kentucky, no additional tornadoes were reported there.

Tornado in JOHNSON, ILLINOIS
From 18-OCT-04 18:19:00 to 18-OCT-04 18:25:00 (CST)
Location: GOREVILLE
Tornado F-scale: F1
Property damage: 10K
Reported by: NWS STORM SURVEY

From Union County, the tornado crossed into extreme northwest Johnson County, only about a half mile south of the Williamson County line. The tornado then moved northeast into Williamson County where Interstate 57 crosses the county line. A semi was overturned on Interstate 57 less than a mile south of the Interstate 24 interchange. The driver was injured. Peak winds along this portion of the tornado path were around 75 MPH.

Hail in WILLIAMSON, ILLINOIS
From 18-OCT-04 18:07:00 to 18-OCT-04 18:07:00 (CST)
Location: MARION
Magnitude: 1.75 
Reported by: TRAINED SPOTTER

Thunderstorm Wind in JACKSON, ILLINOIS
From 18-OCT-04 18:07:00 to 18-OCT-04 18:07:00 (CST)
Location: CARBONDALE
Magnitude: 52 EG
Reported by: TRAINED SPOTTER

Numerous trees were blown down.

Tornado in WILLIAMSON, ILLINOIS
From 18-OCT-04 18:25:00 to 18-OCT-04 18:28:00 (CST)
Location: PULLEYS MILL
Tornado F-scale: F1
Property damage: 25K
Reported by: NWS STORM SURVEY

The tornado entered Williamson County from Johnson County where Interstate 57 crosses the county line.  The tornado passed less than a half mile south of the junction of Interstates 24 and 57. The tornado was only on the ground for about a mile in Williamson County before turning back southeast into Johnson County near Route 37. In the community of Pulleys Mill, dozens of large trees were topped or uprooted, one home received partial roof damage, and a garage roof was peeled. Utility poles and lines were downed. Peak winds along this segment of the tornado were estimated near 80 MPH.

Tornado in UNION, ILLINOIS
From 18-OCT-04 18:16:00 to 18-OCT-04 18:19:00 (CST)
Location: WAYSIDE
Tornado F-scale: F1
Property damage: 4K
Reported by: NWS STORM SURVEY

The tornado touched down in the extreme northeast corner of Union County, only about one-half mile from the Johnson County line. A metal machine shed was destroyed. The television antenna on a nearby home was blown down. Branches were blown down, and a few trees were snapped. The estimated winds were around 75 MPH. The tornado moved into northwestern Johnson County.

Tornado in JOHNSON, ILLINOIS
From 18-OCT-04 18:28:00 to 18-OCT-04 18:35:00 (CST)
Location: GOREVILLE
Tornado F-scale: F2
Property damage: 500K
Reported by: NWS STORM SURVEY

The tornado turned east-southeast from Williamson County back into Johnson County. The bulk of the damage and injuries occurred in a neighborhood on the southern half of the Lake of Egypt. The two injured persons were mobile home residents whose homes were demolished. One of the mobile homes was swept clean off its foundation. The demolished home was deposited 50 to 100 yards away. The 32-year-old male occupant of the mobile home, who was ejected from the home, received numerous bruises and cuts. A female resident of another mobile home was injured. In total, three mobile homes were destroyed, and dozens of mobile homes, barns, and sheds were damaged. Rescue efforts were hampered by a large amount of tree debris on roads. Peak winds in the Lake of Egypt neighborhood were estimated near 120 MPH. The tornado lifted as it reached the southeast side of the Lake of Egypt. The parent thunderstorm produced another tornado in northern Johnson County only a few miles beyond where this tornado lifted.

Tornado in JOHNSON, ILLINOIS
From 18-OCT-04 18:43:00 to 18-OCT-04 18:55:00 (CST)
Location: TUNNEL HILL
Tornado F-scale: F1
Property damage: 50K
Reported by: NWS STORM SURVEY

This tornado touched down less than ten minutes after an earlier tornado in northern Johnson County lifted. Both tornadoes were produced by the same supercell thunderstorm. The tornado tracked entirely across Shawnee National Forest land, causing extensive tree damage. Near the touchdown point, a mobile home was destroyed, and another mobile home was damaged. In the community of Ozark, the general store received extensive roof damage. Branches were blown down in the community, and large trees were down 1 to 2 miles east of Ozark. The tornado strengthened to F-2 intensity after crossing into Pope County.

Tornado in POPE, ILLINOIS
From 18-OCT-04 18:55:00 to 18-OCT-04 19:04:00 (CST)
Location: ABBOTT
Tornado F-scale: F2
Property damage: 150K
Reported by: NWS STORM SURVEY

This tornado entered Pope County from Johnson County in a remote area of the Shawnee National Forest. Most of the track was through heavily forested areas, causing extensive tree destruction. The tornado reached its peak intensity about a mile northeast of Bell Smith Springs, a scenic river gorge about 4 miles northwest of Eddyville. Peak winds were estimated near 120 MPH. Near the end of the damage path, just as the tornado was reaching Illinois Route 145, a mobile home was damaged.