A mature, very intense derecho moved rapidly east along a stationary front across the Mid Mississippi Valley into the Lower Ohio Valley. With a very moist and unstable atmosphere, along with strongly veering winds aloft, embedded tornadic supercells were associated with the derecho. Widespread damaging winds were the primary impact. Nearly all the damage in southern Illinois was associated with the comma head at the northern end of the bow echo. Winds were measured slightly over 100 mph under the comma head as it passed through the Carbondale area. In addition to damaging winds, the slow-moving storm complex dumped very heavy rain that flooded roads.

Flash Flood in FRANKLIN, ILLINOIS
From 08-MAY-09 11:20:00 to 08-MAY-09 15:00:00 (CST-6)
Location: SESSER
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Widespread flooding was reported over many county roads. Extensive street flooding occurred in West Frankfort. In Christopher, a home was surrounded by floodwater, and a nearby outbuilding was flooded.

Thunderstorm Wind in JOHNSON, ILLINOIS
From 08-MAY-09 12:15:00 to 08-MAY-09 12:50:00 (CST-6)
Location: GOREVILLE
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Scattered tree limbs and a few trees were blown down on the northern edge of the county. The vast majority of the damage associated with the comma head of a bow echo passed north of the county.

Thunderstorm Wind in UNION, ILLINOIS
From 08-MAY-09 10:30:00 to 08-MAY-09 10:30:00 (CST-6)
Location: DONGOLA
Magnitude: 65.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Three residences were damaged. One of the residences was a mobile home that was moved two feet off its foundation. The home was tied down, which prevented it from rolling. The frame of a neighboring mobile home was bent, its windows were blown out, and the porch was destroyed. Shingles and siding were blown off a house. A large garage sustained extensive damage, mainly to the roof. An outbuilding was blown over. A barn and a shed were destroyed. A calf was killed inside the barn. An antenna tower was blown over. A satellite dish was blown onto a vehicle. Many large trees, power lines, and a power pole were down.

Hail in WILLIAMSON, ILLINOIS
From 08-MAY-09 10:39:00 to 08-MAY-09 10:44:00 (CST-6)
Location: COLP
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in FRANKLIN, ILLINOIS
From 08-MAY-09 12:18:00 to 08-MAY-09 12:19:00 (CST-6)
Location: ROYALTON
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

This brief tornado was photographed by emergency management personnel. Leaves were observed in the rotation. No damage was located.

Flash Flood in HAMILTON, ILLINOIS
From 08-MAY-09 12:00:00 to 08-MAY-09 15:00:00 (CST-6)
Location: DELAFIELD
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Widespread flash flooding of many roads occurred from Mcleansboro south. A vehicle was stranded in floodwaters under the viaduct on Illinois Route 14 in Mcleansboro. The occupants were on top of the roof of their car. Rescue personnel pushed the car to safety. Another vehicle was stuck in floodwaters near a bridge in the southeast part of the county. The motorist did not require assistance.

Thunderstorm Wind in UNION, ILLINOIS
From 08-MAY-09 11:40:00 to 08-MAY-09 12:30:00 (CST-6)
Location: WOLF LAKE
Magnitude: 65.00 EG
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Newspaper

Northwest parts of the county were struck hardest by very strong winds associated with the comma head of a bow echo. Widespread tree and power line damage occurred. The most intense destruction was in the Wolf Lake and Alto Pass areas. About 25 homes sustained damage in the county. Power outages were widespread. Numerous trees were snapped along Illinois Route 127, mainly north of Anna. The highway was closed while fire and highway personnel worked to clear it. A large tree fell in Anna, taking down power lines and a couple utility poles.

Flash Flood in PERRY, ILLINOIS
From 08-MAY-09 11:02:00 to 08-MAY-09 15:00:00 (CST-6)
Location: WINKLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Water was over roadways around the county. Many rural roads were closed due to high water over them. Flash flooding occurred on U.S. Route 51 in DuQuoin. In Pinckneyville, three-quarters of an inch of rain fell in less than thirty minutes.

Heavy Rain in WILLIAMSON, ILLINOIS
From 08-MAY-09 11:01:00 to 08-MAY-09 12:00:00 (CST-6)
Location: MARION
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Ponding of water occurred throughout Marion. Visibility was down to one block at times in heavy rain.

Thunderstorm Wind in HAMILTON, ILLINOIS
From 08-MAY-09 12:30:00 to 08-MAY-09 13:30:00 (CST-6)
Location: RURAL HILL
Magnitude: 52.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Hamilton County avoided the major wind impact that occurred in places to the south and southwest from a major derecho. There were a few trees down in the Walpole area, but no structural damage was reported.

Tornado in FRANKLIN, ILLINOIS
From 08-MAY-09 12:45:00 to 08-MAY-09 12:48:00 (CST-6)
Location: THOMPSONVILLE
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado resulted in a swath of downed trees in rural areas. Peak winds were estimated near 90 mph. The tornado path continued into Williamson County.

Tornado in WILLIAMSON, ILLINOIS
From 08-MAY-09 12:48:00 to 08-MAY-09 12:51:00 (CST-6)
Location: CORINTH
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado continued into Williamson County from Franklin County. There was a swath of downed trees in rural areas. Peak winds around 90 mph occurred in the Franklin County portion of the track.

Flash Flood in JEFFERSON, ILLINOIS
From 08-MAY-09 12:00:00 to 08-MAY-09 15:00:00 (CST-6)
Location: CRAVAT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

High water was reported across many county roads.

Thunderstorm Wind in WILLIAMSON, ILLINOIS
From 08-MAY-09 12:15:00 to 08-MAY-09 13:15:00 (CST-6)
Location: CARTERVILLE
Magnitude: 87.00 EG
Property damage: 175.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

Widespread wind damage occurred countywide. Extensive tree and power line damage resulted in power outages up to several days long. Many power poles were snapped. Countywide, efforts to restore power were complicated by swampy fields, mud, and downed trees. Ninety-five percent of the county was without power at the peak of the outages. Numerous permanent structures were damaged, including major businesses in downtown Marion and Herrin. A total of 33 homes were heavily damaged or destroyed. It is estimated that over 10,000 homes in the county received minor damage (less than 50,000 dollars per house). Gas leaks were common. Most communication by phone was impossible, including cell phones. Stores were closed, making groceries and gas very difficult to obtain locally in the immediate aftermath of the storm. Travel was nearly impossible due to debris and trees blocking roads. While about two dozen people were treated for storm-related injuries at local hospitals, all but one of them was due to post-storm cleanup. Many school facilities were damaged. The roof of Carterville High School was severely damaged. Several windows were blown out of the school. Minor damage occurred at athletic facilities, including the roof blown off a baseball dugout. Many outbuildings and small structures were destroyed across the county. In Carterville, a garage was lifted and dropped on a vehicle. Many vehicles countywide were damaged or destroyed by falling tree and building debris. A state disaster declaration was granted. A dusk-to-dawn curfew was imposed, and a state of emergency was declared. The Williamson County airport near Marion reported a peak gust of 86 mph. Based on the most severe structural damage east of the airport, peak winds were estimated by storm surveyors close to 100 mph. There was extensive damage at the airport, including hangar buildings. A television station on Route 13 was knocked off the air due to structural and roof damage. All along Route 13, signs were blown down, power poles were down, and windows were smashed. Car dealerships along Route 13 sustained damage due to signs falling on vehicles and windows being blown out. Numerous structures sustained varying degrees of roof damage. A large hotel near the Interstate 57 interchange sustained major roof damage. Many trees were down along Interstate 57 from the Route 13 interchange northward, blocking the southbound lanes. Semis on the interstate were overturned or blown off the highway, causing extended traffic delays. One of the drivers of the semis was seriously injured. A tree fell on a van on the interstate. Damaged or destroyed trees were too numerous to count. Cleanup was expected to last through Labor Day, according to the Mayor of Marion.

Thunderstorm Wind in JACKSON, ILLINOIS
From 08-MAY-09 11:52:00 to 08-MAY-09 12:45:00 (CST-6)
Location: NEUNERT
Magnitude: 92.00 EG
Property damage: 100.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

Widespread wind damage occurred across Jackson County. Widespread damage to trees, power lines, and structures occurred as the comma head of a bow echo moved east across the county. In the city of Carbondale alone, officials reported 34 properties were deemed total losses from the storm. All but nine of those properties were mobile homes. Damage in the city alone (excluding Southern Illinois University) was estimated near 3 million dollars. Officials estimated about 3,000 trees were down or damaged in Carbondale alone, including the campus of Southern Illinois University. Officials in Murphysboro reported 17 dwellings in that city were total losses. One mobile home was blown over onto a car. Murphysboro officials also reported a police cruiser, a truck, and a mobile command center were destroyed. The city's public works garage was shifted off its foundation, and the city police station was damaged. The peak gust recorded by the automated system at the Carbondale airport was 81 mph before the system failed. An observer at the airport visually observed a separate anemometer located on the rooftop reach 106 mph.  The automated system measured a sustained wind of 68 mph before failing. Numerous permanent structures and vehicles were damaged countywide.  Small outbuildings were destroyed. The roof of a school collapsed. Carbondale was virtually impassable due to debris. One fatality occurred on Old Route 13 in Murphysboro when a large tree limb fell on a home, knocking an elderly man down a flight of stairs and causing a severe head injury. Emergency responders were delayed by blocked roads. A state disaster declaration was granted for Jackson County. A curfew and state of emergency was declared. Cleanup was expected to take most or all of the summer. Hundreds of trees were blown down in parks, which were closed indefinitely. The preliminary damage estimate for Southern Illinois University was 5 million dollars. Many buildings on campus sustained roof damage. The storm blew out nearly 100 windows in residence halls. Countywide, efforts to restore power were complicated by swampy fields, mud, and downed trees. Eighty-seven percent of the county was without power at the peak of the outages. Widespread power and telephone outages complicated recovery efforts. Most roads were blocked by debris and downed trees. Gas stations were closed in many areas, adding to problems obtaining fuel for generators. Red Cross shelters were opened in Carbondale and Murphysboro. Major grocery stores were closed for at least 12 to 24 hours, and much of their frozen food was lost. Most communication by cell phone and land line was impossible.

Thunderstorm Wind in SALINE, ILLINOIS
From 08-MAY-09 12:30:00 to 08-MAY-09 13:30:00 (CST-6)
Location: NEWHOPE
Magnitude: 78.00 EG
Property damage: 4.50M
Crop damage: 0.00K
Reported by: NWS Storm Survey

Widespread wind damage occurred across the county. The pockets of greatest damage were in northern parts of the county including Galatia and Raleigh, as well as southwestern parts around Carrier Mills. Harrisburg itself escaped the worst of the damage, and power outages there only affected several hundred customers. Winds were estimated near 90 mph in the Harco area. Extensive power outages lasted three to six days in the hardest hit areas, including Galatia. The power losses rendered pumping stations that supply water inoperable. Many structures were damaged. Every street in Galatia had trees down across streets, houses, vehicles, or outbuildings. Two homes in Galatia received major damage. Barns were destroyed in the Harco area. A mobile home used as a school for the Amish blew off its foundation. Some roofs were blown off. Other structures were damaged by falling trees. A semi was blown over north of Harrisburg on Illinois 34. Emergency responders had difficulty reaching the scene due to downed trees. Many roads were closed by downed trees and power lines, including major routes such as Illinois 34 and U.S. Highway 45. A state disaster declaration included Saline County.

Thunderstorm Wind in FRANKLIN, ILLINOIS
From 08-MAY-09 12:15:00 to 08-MAY-09 13:15:00 (CST-6)
Location: WEST FRANKFORT
Magnitude: 74.00 EG
Property damage: 6.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

Widespread damaging winds across southern Franklin County caused lots of power outages. At the peak of the outages, 49 percent of the county was without power. A state disaster declaration was granted for Franklin County. Among the hardest hit cities was West Frankfort. Peak winds were estimated around 60 mph at Benton, but from 80 to 90 mph around West Frankfort and near the Williamson County line. Thirteen homes were destroyed beyond repair. Damage assessments indicated 184 dwellings sustained damage countywide. Of that number, 114 sustained minor damage, and 70 needed moderate repairs. Numerous trees were blown down, blocking some of the main roads. Near the Williamson County line, trees were blown across the southbound lanes of Interstate 57. Secondary roads stayed blocked for longer periods of time. The hardest hit areas were in and near Royalton, Zeigler, Orient, West Frankfort, and Thompsonville. In Christopher, sheds and carports were overturned, and trees were down on roads and power lines. An uprooted tree landed on a house. The community park in West Frankfort was closed for a little over a week due to downed trees and fences. Some schools were closed for part of the week following the storm.

Thunderstorm Wind in PERRY, ILLINOIS
From 08-MAY-09 12:00:00 to 08-MAY-09 12:45:00 (CST-6)
Location: WILLISVILLE
Magnitude: 61.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Across far southern parts of the county including DuQuoin, numerous trees, limbs, and power lines were blown down. This resulted in power outages, though of a much shorter duration than counties to the south. Sheet metal roofing was blown off a house in DuQuoin. This damage occurred on the northern fringe of the widespread high winds associated with a derecho.

Tornado in JACKSON, ILLINOIS
From 08-MAY-09 12:12:00 to 08-MAY-09 12:13:00 (CST-6)
Location: ELKVILLE
Tornado F-scale: EF0
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Newspaper

Damage was reported at a coal company, where an office trailer was blown off its foundation. There were several eyewitness accounts of a tornado. Peak winds were estimated near 70 mph.

Tornado in JACKSON, ILLINOIS
From 08-MAY-09 10:32:00 to 08-MAY-09 10:33:00 (CST-6)
Location: RADDLE
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

The reported tornado briefly touched down in a field and caused no known damage.

Tornado in JACKSON, ILLINOIS
From 08-MAY-09 10:30:00 to 08-MAY-09 10:34:00 (CST-6)
Location: SATO
Tornado F-scale: EF1
Property damage: 80.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Dozens of large trees were snapped or uprooted. Structural damage occurred to two barns, mainly in the form of roof damage. Power poles were blown over, and one pole snapped. Houses received minor shingle damage. Peak winds were estimated near 95 mph.