RSS FeedsHydrologic Summary for July 2003 for the Area Served by the NWS Forecast Office at Sioux Falls, SD
Summary
Heavy rains fell across portions of southeast South Dakota and northwest Iowa during the first ten days of July. Flash Flood warnings were issued for 7 counties, and flood warnings were issued for parts of the Floyd and Little Sioux rivers.
Flooding
Minor flooding occurred on parts of the Little Sioux River following heavy rains that fell between the 3rd and 9th of July. The gage at Cherokee was the only site to go above flood stage, but Spencer and Linn Grove also saw significant in-bank rises during this time. The upper Floyd River near Alton also saw large in-bank rises. Flash Flooding of small creeks, streams, county roads, and urban areas was also reported in early July. Eastern Woodbury, Ida, Cherokee, and Buena Vista counties in northwest Iowa were hit by heavy rains and flash flooding for the second month in a row, as were Turner and Clay counties in southeast South Dakota.
General Hydrologic Information
Temperatures in July were near normal to slightly above normal across the region, generally ranging between 1 ½ degree above and ½ degree below the 30 year average.Precipitation for the month varied widely across the region, as is normal with summertime convection. The northern portions of southeast South Dakota into southwestern Minnesota missed out on most of the heavier rains, with most areas receiving 1 to 2 inches, which is 1 to 2 ½ inches below normal. The areas south of I-90 in South Dakota across into northwestern Iowa received more rainfall in July. Monthly totals of 3 to 5 inches were reported, which is near normal to 1 ½ inches above normal.
Soil Moisture conditions at the end of July were slightly below normal along and north of I-90 in South Dakota and Minnesota, with near normal to slightly above normal conditions in the southern portions of the region. Streamflows on the main rivers in the region were generally near normal at the end of the month. The National Drought Monitor showed abnormal dryness in areas along the Missouri River above Fort Randall Dam at the end of July.
Mike Gillispie
August 6, 2003
August 6, 2003
