ST. CHARLES, Mo. - For much of the late spring and early summer, the Bi-state region’s rivers were in flood, leading to millions of dollars in damages. But forecasters are already worried for what spring 2020 may have in store.
Both the Missouri and Mississippi rivers finally dropped below the flood action stage earlier this week, but there's still a lot of water flowing through those river basins. If you look at USGS flow percentiles, both rivers are running way above normal for this time of year.
Soil moisture also remains very high in the upper Mississippi and middle and lower Missouri river basins, meaning there's very little room to put any additional precipitation that falls or melts this winter and next spring.
And to top it all off, the Climate Prediction Center’s winter outlook is a basically a worst-case scenario for the upper Mississippi and lower Missouri basins, showcasing a high probability for above-normal precipitation coupled with near-normal temperatures, implying a very active snow season for the Dakotas, Iowa, Minnesota, northern Illinois, and Wisconsin.
"You put those two things together, high rivers, high soil moisture, there’s just not much room left for additional precipitation," explains NWS Senior Service Hydrologist Mark Fuchs. "And that’s where the CPC winter outlook comes in. They just updated it and that winter outlook is showing an above-average chance for above-average precipitation for not just for the upper Missouri but also the upper Mississippi basins. None of that looks good if you want lower water in the spring."
Fuchs feels that even if the upper Midwest and northern Great Plains see just average snowfall this winter, we're looking at a chance for at least moderate flooding next spring.