Flash Flood — Sangamon, Illinois

2016-08-12 · near Cantrall, Sangamon, Illinois

Event narrative

Persistent thunderstorms produced heavy rainfall during the early evening in Sangamon County and the western half of Springfield with 2.50 to 6.00 inches in less than three hours. Some locations reported more than 3.00 inches of rain between 1700 and 1800 CST. Numerous city streets in Springfield were closed due to the flooding, including all of the roads in the vicinity of the Illinois State Fairgrounds where the annual State Fair was starting. A total of 58 camper trailers and 25 vehicles were damaged on the State Fairgrounds, where nearly 50 people were rescued in the camping area. No injuries were reported. Many livestock buildings were flooded, the Grandstand concert was cancelled, and fair officials closed the entrance/exit gates to keep people from leaving due to the extensive street flooding. In other areas of Springfield, 48 water rescues were made on city streets and viaducts by first responders, with no injuries reported. In other parts of the county, rural roads north of Springfield toward Cantrall, and west of Springfield toward New Berlin were impassable. State Highways 4, 29, 97 and 125 were also closed in spots due to flowing water and flooding.

Wider weather episode

An approaching cold front triggered thunderstorms across central Illinois during the late afternoon and evening of August 12th. Due to copious amounts of moisture in the atmosphere and the slow-moving nature of the storms, extremely heavy rain fell along and just west of I-55. The heaviest rain occurred in a swath from southern Woodford County southward into western Sangamon County where 3.00 to 6.00 inches were common. The Springfield Airport set a new daily record for August 12th and a new calendar day record for any date of 5.59 inches. The highest totals of around 8.00 inches were focused across southern Tazewell County near the town of Delavan. The tremendous amount of rain coming down in a short period of time created flash flooding in many areas. Numerous roads had water flowing across them across portions of Tazewell, Logan, Mason, Menard, and Sangamon counties. In addition, the Illinois State Fair was getting underway in Springfield, where 50 people had to be rescued due to rising waters.

View location on OpenStreetMap → (39.9753, -89.6986)

Source: NOAA Storm Events Database, event_id 658359. Narrative written by the NWS forecast office that issued the report.