Flood warnings issued for O'Brien, Dickinson counties; flash flood watch for Friday for region
3:06 p.m. Update
SIOUX FALLS, S.D. - A flash flood watch will be in effect from Friday evening through late Friday night for Cottonwood, Jackson, Murray, Nobles, Pipestone, Rock, Lincoln and Lyon counties in southwest Minnesota and Dickinson, Lyon, O'Brien, Osceola, Buena Vista, Cherokee, Clay, Ida, Plymouth, Sioux and Woodbury counties in northwest Iowa.
According to the National Weather Service:
Thunderstorms should develop near the James Valley in South Dakota Friday afternoon, and then move east and southeast over the area Friday night. Abundant moisture and instability will be available with this system, and the potential is there for additional very heavy rain.
At this time, the biggest threat for widespread heavy rain should be in the vicinity of southwest Minnesota, with somewhat lesser threat to the west and south. However, any heavy rains could lead to flash flooding over already saturated ground.
A flash flood watch means that conditions may develop that lead to flash flooding. People should monitor later forecasts and be prepared to take action should flash flood warnings be issued.
12:35 p.m. Thursday
SIOUX FALLS, S.D. - The National Weather Service has issued a flood warning for some rivers in O'Brien and Dickinson counties in Iowa, including:
- The Floyd River at Sheldon, until 1 a.m. Saturday. At 7 a.m. Thursday, the stage was 11.3 feet. Flood stage is considered to be 12.0 feet, and moderate flooding is forecast. The river is projected to rise above flood stage by 9 a.m. Thursday and crest near 14.1 feet by July 22. The river will fall below flood stage by July 23. At stages near 14.0 feet, flooding affects large areas of farmland within 1,000 feet of the river.
- The Floyd River at Alton
- Little Sioux River near Milford, until further notice. At 8 a.m. Thursday the stage was 12.4 feet. Flood stage is considered to be 12.0 feet, at which minor flooding of low-lying agricultural lands begins.
- Little Sioux River at Spencer
- Little Sioux River at Linn Grove
- West Fork Ditch near Hornick
The following river forecasts include forecast precipitation through this afternoon. Any additional future rains could affect the crest forecasts.
Rainfall of 2 to 6 inches occurred last night and this morning across northwest Iowa. This will result in the Little Sioux and Floyd Rivers rising above flood stage.
The National Weather Service advised against driving cars through flooded areas. The water depth and road condition may be unsafe.