Significant river flooding not expected through this spring
We wrapped up winter with an active February with several winter weather events and a long cold stretch, but we actually ended up with less snow than normal through March 1st.
Snow amounts across the upper Midwest were similar, which bodes well for our rivers this spring.
2020 ended up being fairly tame as far as severe weather goes. Thunderstorms were reported 43 days of the year, and our spring rainfall was slightly above average.
Despite the uptick in rainfall and deeper snow pack upstream last year, river flooding wasn't much of an issue.
We're tracking near normal flood conditions this spring, with minor flooding possible on the Missouri River through late May. With no ongoing river flooding, stream flows appear normal along the Missouri and smaller rivers despite the recent ice jam near Jefferson City in February that backed up flow for a few days.
Rainfall in early March could temporarily send smaller river levels up, but snow cover was much lower than average across the upper Missouri Basin in Minnesota and the Dakotas. Soil moisture is also lower than normal in these areas.
The drier environment will allow more storage in the upper Missouri River Basin for the months to come. However, with more snow cover in Iowa and eastern Nebraska this winter, there could be some minor flooding impacts downstream in our area.
There is a 50% chance of surpassing minor flood levels in Hermann, Boonville, Glasgow, and Chamois. There is a 75% chance of reaching minor flood stage on the Moreau River in Jefferson City, and on the Petite Saline in Boonville. The Grand River in Chariton County has a 75% chance of reaching moderate flood stage.
Rainfall is expected to be near average this spring, but heavy rain or thunderstorm events could temporarily cause rises in river levels, especially on smaller streams.
The black line on the below graph shows the historical chance of reaching each flood stage at Glasgow, while the red line shows the forecast given the current conditions. This year, we are trending below the historical average, meaning flooding is likely to be less impactful this year. Hermann is closer to the yearly average through minor flood stage, with even less of a chance of reaching moderate flood stage.