A large upper trough with a closed upper low slowly moved east across the Central United States March 17th through the 19th. This allowed a strong southerly flow to transport copious amounts of moisture from the deep south into the Midwest.  Several waves of low pressure moved along a nearly stationary frontal boundary that remained just south of the forecast area, across northern Arkansas and extreme southern Illinois. Several rounds of rain and thunderstorms brought locally heavy rainfall to much of the forecast area, with the greatest amounts confined along and south of Interstate 44 in Missouri and Interstate 70 in Illinois. Total rainfall ranged from less than an inch across portions of west central Illinois to almost 10 inches in southern Reynolds County, Missouri. The excessive rainfall led to flash flooding of low lying areas and major flooding on local rivers and creeks for the next week. Many people were affected by this event, with millions of dollars in damage recorded across the forecast area.

Flash Flood in WASHINGTON, ILLINOIS
From 18-MAR-08 17:20:00 to 19-MAR-08 03:00:00 (CST-6)
Location: VENEDY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Up to 6 inches of rain fell on already saturated soils in Washington county from the late evening hours of March 17th through March 18th.  Numerous roads were flooded throughout the county.  Northeast of Hoyleton, there was an estimated 4 feet of water flowing over the intersection of Sycamore Road and Peach Tree Road due to Indian Point Creek overflowing its banks. Also, about 6 miles south southeast of Nashville, Posen Road was inundated about a mile east of Illinois Route 127. The city of Nashville reservoir a mile east of town was dangerously close to overflowing during the event.

Flash Flood in ST. CLAIR, ILLINOIS
From 18-MAR-08 03:30:00 to 18-MAR-08 04:30:00 (CST-6)
Location: BELLEVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Two to three inches of rain fell onto already saturated soils in St. Clair county from the evening hours of March 17th through March 18th. Several roads had water flowing over them including Jefferson Road between Illinois Routes 13/15 and Illinois Route 4.

Flash Flood in MARION, ILLINOIS
From 18-MAR-08 17:20:00 to 19-MAR-08 03:00:00 (CST-6)
Location: VERNON
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: County Official

Up to 7 inches of rain fell on already saturated soils in Washington county from the late evening hours of March 17th through March 18th.  Numerous roads were flooded throughout the county.  Salem Town Creek which runs from the reservoir on the north side of Salem towards the east then southeast side of town where there is another reservoir, was overflowing.  A mobile home park on the east side of town near the eastern reservoir had 6 to 8 inches of water surrounding 6 mobile homes, but did not flood the structures themselves.  Just east of Central City, a combination of 16 homes and mobile homes were experiencing high water due to Raccoon Creek being out of its banks.

Flash Flood in RANDOLPH, ILLINOIS
From 18-MAR-08 19:30:00 to 19-MAR-08 03:00:00 (CST-6)
Location: CHESTER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Up to 6 inches of rain fell on already saturated soils in Randolph county from the late evening hours of March 17th through March 18th.  Numerous secondary roads were flooded throughout the county.