Isolated supercell thunderstorms moved into southern Illinois during the evening hours. The storms developed ahead of a cold front in a destabilizing air mass characterized by dew points in the lower to mid 60's. The most intense supercell storm awaited the approach of a mid-level impulse from Oklahoma, which was downstream from the primary shortwave trough over the southern Plains. The supercell produced two long-track strong tornadoes, the first of which originated in Perry County, Missouri and tracked almost 50 miles before dissipating. The second strong tornado formed in the Wabash Valley and crossed into southwest Indiana. A southwesterly low-level jet increased substantially during the evening, creating favorable conditions for tornadoes.

Funnel Cloud in WILLIAMSON, ILLINOIS
From 28-FEB-17 22:56:00 to 28-FEB-17 22:56:00 (CST-6)
Location: JOHNSTON CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The funnel cloud was observed by a trained spotter.

Hail in FRANKLIN, ILLINOIS
From 28-FEB-17 21:00:00 to 28-FEB-17 21:04:00 (CST-6)
Location: BENTON
Magnitude: 3.00 
Crop damage: 0.00K
Reported by: Trained Spotter

This large hail was associated with the supercell that produced a strong tornado in Jackson and western Franklin Counties. Hailstones were slightly larger than baseballs on the north side of Benton. Quarter-size hail fell on the west side of Benton.

Hail in WHITE, ILLINOIS
From 28-FEB-17 21:54:00 to 28-FEB-17 22:00:00 (CST-6)
Location: CROSSVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

This large hail was associated with the tornadic supercell that produced the strong tornado that passed south of Crossville into southwest Indiana.

Hail in JACKSON, ILLINOIS
From 28-FEB-17 22:29:00 to 28-FEB-17 22:29:00 (CST-6)
Location: CARBONDALE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in JACKSON, ILLINOIS
From 28-FEB-17 22:30:00 to 28-FEB-17 22:30:00 (CST-6)
Location: MURPHYSBORO
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in WILLIAMSON, ILLINOIS
From 28-FEB-17 22:56:00 to 28-FEB-17 22:56:00 (CST-6)
Location: JOHNSTON CITY
Magnitude: 3.00 
Crop damage: 0.00K
Reported by: Trained Spotter

Hail slightly larger than baseballs was associated with the supercell that spawned the EF-1 tornado further south in Williamson County.

Tornado in JACKSON, ILLINOIS
From 28-FEB-17 20:18:00 to 28-FEB-17 20:50:00 (CST-6)
Location: CORA
Tornado F-scale: EF3
Property damage: 6.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

This large tornado entered Jackson County from Randolph County near the community of Rockwood. The tornado originally began near Perryville, Missouri, where it achieved its peak intensity in the EF-4 category. The tornado crossed the entire width of Jackson County, entering the county about two miles from the Mississippi River. The tornado passed just south of Ava, clipped the southern edge of Vergennes, and then passed near the north edge of Elkville before exiting the northeast corner of the county. In Jackson County, the tornado reached a maximum intensity of EF-3 on the south end of Vergennes. Winds estimated near 145 mph destroyed a house. The wood house was not securely anchored to the foundation, and other construction details suggested wind speeds were below the EF-4 category. Elsewhere in Jackson County, the tornado passed through mainly rural farmlands and woods. Thousands of large trees were snapped and uprooted, and dozens of homes and other structures were damaged or destroyed. The tornado remained quite wide, nearly one-third of a mile at times. The average path width in Jackson County was about 600 yards. The tornado continued east-northeast into Franklin County.

Tornado in FRANKLIN, ILLINOIS
From 28-FEB-17 20:50:00 to 28-FEB-17 20:57:00 (CST-6)
Location: MULKEYTOWN
Tornado F-scale: EF3
Property damage: 800.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This large tornado entered Franklin County from Jackson County. The tornado originally formed near Perryville, Missouri. The most intense damage in Franklin County was located south of Mulkeytown, where the tornado was rated EF-3 based on a house that was swept clean off its foundation. Debris was thrown up to a mile downwind. The debris was shredded, with nothing larger than 2-by-4 wood pieces. However, the house was sitting on a block foundation, unattached to anything. Based on the lack of any anchors for the house, peak winds were estimated near 160 mph at this site. Most of the other damage in this rural area of Franklin County consisted of snapped trees, heavily damaged barns, and a few damaged houses. The tornado rapidly weakened from EF-3 intensity to complete dissipation during the final two miles of its path. The average path width in Franklin County was 340 yards. The total path length starting near Perryville, Missouri was nearly 50 miles. The tornado dissipated just southwest of Christopher.

Tornado in WILLIAMSON, ILLINOIS
From 28-FEB-17 22:44:00 to 28-FEB-17 22:54:00 (CST-6)
Location: CRAINVILLE
Tornado F-scale: EF1
Property damage: 6.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado skipped along the path, bringing down large tree limbs from Crab Orchard Lake to Interstate 57 a few miles north of Marion. Most of the tornado track was EF-0, except for an uprooted tree or two west of Interstate 57 near Whiteash. Peak winds were estimated near 95 mph.

Hail in JACKSON, ILLINOIS
From 28-FEB-17 22:18:00 to 28-FEB-17 22:18:00 (CST-6)
Location: GRAND TOWER
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Tornado in WHITE, ILLINOIS
From 28-FEB-17 21:55:00 to 28-FEB-17 22:08:00 (CST-6)
Location: CARMI MUNI ARPT
Tornado F-scale: EF3
Property damage: 2.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado touched down between Crossville and Carmi, quickly strengthening to EF-3 intensity before crossing Illinois Route 1. The tornado track stayed northeast of Carmi, in relatively sparsely populated farmland. In White County, 35 structures were damaged or destroyed. At least several of those were homes. Just west of Highway 1, several vehicles were rolled over and moved, and a single-wide mobile home was destroyed. Near where the tornado crossed Route 1, an older house was moved three feet off its foundation. The house did not appear to be bolted to the foundation. Most of the second floor was removed. A double-wide mobile home was destroyed in the same area near Route 1. The width of the damage path was about 300 yards along Route 1. Just south of Crossville on County Road 1675E, a vehicle was rolled about 30 yards, and a house was destroyed. Some walls of the house collapsed, and most of the roof came off. Peak winds at this location were estimated near 150 mph. The sole fatality occurred south of Crossville, where an elderly man was caught outdoors when the tornado struck. The man was found in a farm field about 40 yards from his house. His wife was inside in the house, and she received scrapes and bruises. Another EF-3 damage location was east of Crossville, where a vehicle was moved about 30 yards and an old house was partially destroyed. The average path width was about 300 yards in White County. The tornado continued across the Wabash River into Posey County, Indiana.