Flash Flood — Worth, Iowa

1999-07-19 · near Manly, Worth, Iowa

Wider weather episode

A nearly stationary frontal boundary was draped across Iowa during the afternoon of the 18th into the night. Thunderstorms erupted in the vicinity of the front as dew point temperatures in the mid 70s to around 80 pooled just south of front. Most of the storms produced heavy rain and gusty winds with very few producing severe weather. Two distinct mesoscale convective systems moved across northern Iowa. The first one produced some wind damage as it moved across. Trees were downed in Kossuth County southeast of Irvington. Another cell ripped shingles from a home in Dumont in Butler County. The main problem was flash flooding over north central Iowa. Near Manly in Worth County. 5.75 inches of rain was recorded in a 4 hour period just after midnight. Numerous basements were flooded and roads overtopped by water. Heavy rains also fell over northeast Cerro Gordo County, overtopping many roads with 1 to 2 feet of water. The heaviest rainfall occurred over Worth County. A bucket survey indicated spot 9 to 12 inch rainfall amounts northeast of Manly, with the highest unofficial measurement at 13.5 inches, though there was one report of an incredible 20 inches of rain. The county Emergency Manager reported that 25% of the county was covered by water with at least 75 washouts. It was reported that 550 of the buildings in town, or about half, had water in the basement. A 54 car train was derailed in the area just southwest of Grafton and at least 3 major highways were closed, Iowa Highway 9, U.S. Highway 18, and U.S. Highway 65. Flooding hit a campground southeast of Manly near the town of Rock Falls. One hundred and fifty people were evacuated in the town of Rock Falls itself. The water flooded the campground and debris was recovered three miles downstream of the campground. Flooding affected the town of Greene where half of the businesses in town were flooded. There was also several other evacuations. One of the larger was along the Winnebago River in the Mason City area where 400 homes along the river were ordered evacuated. Some of the totals in property damage include 2 homes destroyed in Worth County, 56 suffered major damage, and 249 sustained minor damage. In Bremer County, 24 homes suffered major damage, while 104 sustained minor damage. Highway and bridge damage in Cerro Gordo County topped $750,000, with $300,000 in road damage in Worth County. Governor Vilsack declared 8 counties in Iowa disaster areas. In the Des Moines CWA, these included Bremer, Butler, Cerro Gordo and Worth. Crop damage was also quite extensive in these two counties with many fields under water. It will be some time before the true extent of the damage is known however. Farther to the south, an isolated thunderstorm moved through Mahaska County and produced high winds. The winds tore the roof off of a mobil home in the town of Fremont.

Source: NOAA Storm Events Database, event_id 5706007. Narrative written by the NWS forecast office that issued the report.