RSS FeedsHydrologic Summary for June 2003 for the Area Served by the NWS Forecast Office at Sioux Falls, SD
Summary
There were several heavy rainfall events across the area in June. The hardest hit areas were in the lower Vermillion River basin in southeast South Dakota, and the Little Sioux River basin in northwest Iowa. Flood warnings were issued for 7 forecast points in these basins, and Flash Flood warnings were issued for 16 counties.
Flooding
There was minor flooding on the Vermillion River in southeast South Dakota and the Little Sioux River in northwest Iowa in June. Additionally, there were three flash flood events across the region in June. Heavy rainfall of 2 to 4 inches fell on the night of the 9th along and south of the Missouri River toward the Sioux City Metro area, resulting in flash flooding on small creeks and urban flooding in Sioux City. Another round of heavy rain fell on the night of the 23rd, and again on the night of the 24th. On the 23rd, areas in northwest Iowa received 3 to 5 inches on average, with isolated maximum amounts of 6 to 8 inches. This was followed on the 24th with more widespread rainfall of 2 to 4 inches, with isolated maximum amounts of 4 to 6 inches, falling across an area from the lower Vermillion River basin in southeast South Dakota through much of northwest Iowa. Flash Flooding and urban flooding occurred in 10 counties during and shortly after the rainfall, and river flooding continued for several days after the event on the Vermillion and Little Sioux Rivers.
General Hydrologic Information
Temperatures in June were below normal across the region, with most areas 1 to 2 degrees below the 30 year average.Precipitation for the month was near to slightly above normal in the northern areas, and above to much above normal in the south. Most of the region received between 3 and 5 inches of rain in June. Some of the highest reported amounts for the month were 10.47” at Sioux Rapids IA, 8.37” at Washta IA, 7.59” at Cherokee IA, 7.17” at Montrose SD, 7.13” at Lake Park IA, 6.80” in northern Sioux City IA, and 6.78” at Howard SD.
Soil Moisture conditions at the end of June were near normal. The drought indices as of the end of June showed no areas of abnormal dryness or drought in southeast South Dakota, southwest Minnesota, or northwest Iowa.
Mike Gillispie
July 15, 2003
July 15, 2003
