Low pressure tracking along a stationary frontal boundary brought several rounds of showers and thunderstorms to central Illinois from the evening of May 18th into the morning of May 19th.  A few cells produced hail as large as quarters: however, the main impact was locally heavy rainfall.  Rain amounts of 3 to 6 inches were common in a corridor from near Jacksonville northeastward through Springfield and Decatur to Champaign.  Due to excessive rainfall rates, flash flooding occurred in many locations.  Several underpasses and viaducts were flooded in Springfield and Decatur, while high water stranded a vehicle on a county road between Cerro Gordo and Bement in Piatt County.

Hail in CHAMPAIGN, ILLINOIS
From 18-MAY-17 21:45:00 to 18-MAY-17 21:50:00 (CST-6)
Location: IVESDALE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in CHRISTIAN, ILLINOIS
From 19-MAY-17 05:33:00 to 19-MAY-17 05:38:00 (CST-6)
Location: EDINBURG
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Flash Flood in MORGAN, ILLINOIS
From 19-MAY-17 02:00:00 to 19-MAY-17 08:30:00 (CST-6)
Location: ALEXANDER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rain of 3.00 to 5.00 inches from the late evening of May 18th through the early morning of May 19th produced flash flooding in eastern Morgan County. Numerous rural roads were closed from Alexander to Rees to Franklin. Illinois Route 104 from Rees to Franklin was also closed in spots. The flooding subsided in most areas around 8:30 am.

Flash Flood in SANGAMON, ILLINOIS
From 19-MAY-17 03:45:00 to 19-MAY-17 08:45:00 (CST-6)
Location: SPRINGFIELD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy rain of 2.00 to 4.00 inches from the late evening of May 18th through the early morning of May 19th produced flash flooding across Sangamon County, mainly along and just south of I-72. The heaviest rain was southwest of New Berlin, near the Morgan County line, and from the east side of Springfield toward Mechanicsburg. Numerous rural roads were closed and several city streets in Springfield were flooded. Heavy rain and ponded water on I-55 on the east edge of Springfield resulted in numerous car accidents during the early morning commute.

Flash Flood in CHRISTIAN, ILLINOIS
From 19-MAY-17 03:30:00 to 19-MAY-17 08:45:00 (CST-6)
Location: ILLIOPOLIS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy rain of 2.50 to 4.00 inches from the late evening of May 18th through the early morning of May 19th produced flash flooding in extreme northern Christian County. Numerous rural roads were closed from Mt. Auburn toward the Sangamon River to the Macon County line. The flooding subsided in most areas before 9:00 am.

Flash Flood in MACON, ILLINOIS
From 19-MAY-17 03:00:00 to 19-MAY-17 08:45:00 (CST-6)
Location: NIANTIC
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy rain of 3.00 to 5.50 inches from the late evening of May 18th through the early morning of May 19th produced flash flooding in central and southern Macon County. Streets were flooded in Decatur and numerous rural roads were flooded from Decatur to Oakley and east toward the Piatt County line. The flooding subsided in most areas before 9:00 am.

Flash Flood in PIATT, ILLINOIS
From 19-MAY-17 02:00:00 to 19-MAY-17 09:00:00 (CST-6)
Location: CISCO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rain of 3.00 to 6.00 inches from the late evening of May 18th through the early morning of May 19th produced flash flooding in central Piatt County. Numerous rural roads were closed from Cerro Gordo through Milmine toward Bement. A vehicle was stranded in the flood waters just north of Route 105, about 3 miles east of Cerro Gordo. No injuries were reported. The flooding subsided in most areas around 9:00 am.