Flash Flood — Stephenson, Illinois

2011-07-27 to 2011-07-28 · near Waddams Grove, Stephenson, Illinois

Event narrative

Torrential rains of 3 to 8 inches caused some flash flooding across parts of Stephenson County during the evening of July 27 and morning of July 28. There were reports of cattle scattered through county by flood waters with some washed downstream. The flood waters were several feet deep in the town of Pearl City. Two people died just west of Freeport, IL from carbon monoxide fumes from a generator use to pump water from a flooded basement.

Wider weather episode

Hot and humid conditions prevailed across the region July 27, as a warm front lifted northward into northeast Iowa. Showers and thunderstorms developed along the Highway 20 corridor in Dubuque, Jo Daviess and Stephenson Counties during the early evening hours of July 27. They continued to redevelop and move over the same areas for about 18 hours. Record-setting rainfall totals of 7 to 15 inches resulted in flash flooding of much of the area. The Mississippi River at Dubuque, IA even rose about 4 feet in 12 hours due to the excessive rainfall. In addition to the heavy rains and flooding, some of the stronger storms producing large hail and a brief tornado. High temperatures on July 27 topped out in the lower and middle 90s. Due to the high humidity levels, low temperatures the morning of July 28 only managed to slip into the 70s and lower 80s.

View location on OpenStreetMap → (42.5000, -89.9200)

Source: NOAA Storm Events Database, event_id 332697. Narrative written by the NWS forecast office that issued the report.