Despite a snow-packed winter, the National Weather Service is predicting minimal risk for flooding this spring in the St. Louis area.
According to the agency’s March 6 spring flood outlook, in the next 90 days minor flooding can be expected on the Mississippi River from southern Iowa to the Missouri River confluence near St. Louis, while flood chances on the Missouri River will be about average.
The Illinois River downstream from Beardstown, Ill., has an above-average chance for minor flooding based on 2 to 4 inches of snow and ice on the ground in the northern river basin. But significant Illinois River flooding is unlikely with average spring rainfall, according to the National Weather Service.
Mississippi River basin snowpack is above average, with 2 to 4 feet common in Minnesota, Wisconsin and Iowa. Snow depths in the Missouri River basin are slightly below the seasonal average, especially between Omaha, Neb., and Bismarck, N.D.; northwestern Missouri into western Iowa have above-average snow cover.
Drought in northern states is the main mitigating factor in this year’s flood forecast. Much of the melting snow and ice will be absorbed by dry soil and low river levels, National Weather Service hydrologist Mark Fuchs said.
The Climate Prediction Center’s 8- to 14-day outlook calls for below-average temperatures in Illinois and Missouri and below-average precipitation.
“If we have a lot more rain than an average spring, then our chances of significant flooding will increase,” Fuchs said. “This is all based on an average rainfall.”