A series of thunderstorm complexes over a period of several days resulted in locally significant flash flooding. A cold front stalled across the Lower Ohio and Mid-Mississippi Valleys, where tropical moisture was already in place. Precipitable water values from 2.25 to 2.5 inches were common. A sub-tropical low pressure system that produced torrential rains along the Gulf of Mexico coast then turned north, eventually getting pulled northeast across Missouri along the stalled cold front. This low brought copious amounts of moisture. Showers and isolated thunderstorms brought torrential downpours between the 13th and 17th. Rainfall amounts during this time ranged up to 5 to 10 inches from the Marion/Carbondale area north to Mount Vernon and west to the Missouri state line.

Flash Flood in JEFFERSON, ILLINOIS
From 13-AUG-16 15:27:00 to 13-AUG-16 18:00:00 (CST-6)
Location: MARCOE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Water was flowing across Highway 148 near the Interstate 57 overpass, making conditions dangerous. A co-operative observer at Waltonville measured 3.79 inches just prior to the start of the flooding. A U.S. Army Corps of Engineers site near Rend Lake recorded a 24-hour total of 6.23 inches.

Flood in PERRY, ILLINOIS
From 14-AUG-16 21:15:00 to 14-AUG-16 22:45:00 (CST-6)
Location: ST JOHNS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Water was over a secondary road near St. Johns. A co-operative observer near Pinckneyville measured a 72-hour rainfall total of 6.57 inches.

Flood in JEFFERSON, ILLINOIS
From 15-AUG-16 09:27:00 to 15-AUG-16 14:00:00 (CST-6)
Location: WALTONVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A tributary creek of the Big Muddy River flooded a rural road just north of Waltonville. The road was impassable due to one to two feet of water across it. The storm total rainfall since August 13 was 10.15 inches at a location a few miles east of Waltonville.

Flash Flood in FRANKLIN, ILLINOIS
From 14-AUG-16 22:00:00 to 15-AUG-16 00:30:00 (CST-6)
Location: WEST FRANKFORT
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A motorist was stranded in three to four feet of water at an intersection in West Frankfort. Public bystanders rescued the motorist. Numerous streets were closed in the city. A Cocorahs (Community Collaborative Rain, Hail, and Snow Network) observer in West Frankfort measured a three-day rainfall total of 7.90 inches.  Ditches were overflowing onto Route 149 east of Zeigler.

Flash Flood in UNION, ILLINOIS
From 13-AUG-16 11:02:00 to 13-AUG-16 18:15:00 (CST-6)
Location: WOLF LAKE
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Just north of Alto Pass, a small bridge across Cave Creek was washed out. The bridge was on a dead-end street off Highway 127. Road crews were dispatched to several flooded roads around the area. A 24-hour rainfall amount of 7.9 inches was reported at Cobden, and just over 5 inches fell at Wolf Lake within 8 hours.

Flash Flood in MASSAC, ILLINOIS
From 17-AUG-16 07:12:00 to 17-AUG-16 09:00:00 (CST-6)
Location: METROPOLIS
Flood cause: Heavy Rain
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

A railroad viaduct was flooded in Metropolis. A vehicle became partially submerged in the floodwater and was towed out. Portions of County Road 1 were flooded in and near the city of Metropolis. Water was over numerous other streets and intersections in the city.

Flash Flood in HAMILTON, ILLINOIS
From 15-AUG-16 05:17:00 to 15-AUG-16 07:30:00 (CST-6)
Location: DALE
Flood cause: Heavy Rain
Property damage: 4.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several people were rescued from a flooded vehicle on a rural road four miles southwest of Mcleansboro. Just north of Dale, a large amount of water was crossing Illinois Route 142 and County Road 700N. There was also a large amount of water crossing Illinois Route 242 north of Mcleansboro near County Road 1800N.

Flash Flood in WILLIAMSON, ILLINOIS
From 13-AUG-16 08:22:00 to 13-AUG-16 14:00:00 (CST-6)
Location: CARTERVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Some roads were closed in and near Carterville and Crainville. A Carterville city street just north of Illinois Route 13 was under six inches of water. A manhole cover popped off, and water was filling up yards. A television station in Carterville measured 4.11 inches from midnight through 7:30 P.M. CST.

Flash Flood in JACKSON, ILLINOIS
From 13-AUG-16 10:15:00 to 13-AUG-16 14:00:00 (CST-6)
Location: BOSKYDELL
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported 1.5 feet of water over a secondary road south of Carbondale leading to Giant City State Park. A rainfall amount of 3.49 inches was measured at a nearby fire station between midnight and 6:45 P.M. CST.

Flood in HAMILTON, ILLINOIS
From 13-AUG-16 10:15:00 to 13-AUG-16 12:15:00 (CST-6)
Location: GARRISON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Two to four inches of water covered Route 242 in the northern portion of the county, about ten miles north of Mcleansboro.

Flash Flood in PERRY, ILLINOIS
From 13-AUG-16 14:50:00 to 13-AUG-16 18:00:00 (CST-6)
Location: TAMAROA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

U.S. Route 51 was closed just south of Tamaroa due to flooding. Water was covering Illinois Route 154 just west of U.S. Highway 51.

Flood in HAMILTON, ILLINOIS
From 15-AUG-16 19:22:00 to 16-AUG-16 02:00:00 (CST-6)
Location: DALE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Rising floodwaters along the north fork of the Saline River closed County Road 500N about three miles east of Illinois Route 142.

Flood in ALEXANDER, ILLINOIS
From 17-AUG-16 06:00:00 to 17-AUG-16 08:00:00 (CST-6)
Location: CAIRO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

U.S. Highway 51 was flooded in a few places in Cairo.

Flash Flood in WILLIAMSON, ILLINOIS
From 14-AUG-16 21:20:00 to 15-AUG-16 00:30:00 (CST-6)
Location: SPILLERTOWN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

The intersection of two county roads just northeast of Marion was under swiftly moving water. Water was bubbling out of the top of a sewer and spilling out of ditches in Marion. An observer near Carterville measured a two-day storm total of 6.5 inches.