Tracking runoff trends along the Missouri River

While the Missouri River is not strikingly wide in most locations, it is the longest river in the United States, snaking over 2,300 miles from the Rocky Mountains of Montana to the eastern edge of Missouri where it drains into the Mississippi River. The Missouri River Basin is all the more expansive, covering more than half-a-million square miles over 10 different U.S. states and one Canadian province. All this to say that a multitude of weather events and patterns influence its water levels from one year to the next.

Less than two weeks ago the Missouri River was filled with chunks of ice along its St. Joseph banks, before a recent warm spell melted away the wintry scene. From late December to mid January, premature melting of snow and ice was a theme for the Missouri River and its tributaries across northern parts of the basin, especially around the head waters in Montana. This early melt-off promoted above normal runoff and water levels last month, especially for points north of Sioux City. 

Water levels on the Missouri River have been within the normal range at the St. Joseph gauge and many points in either direction this week. Meanwhile, runoff in northern stretches of the Missouri River Basin is slowly slacking off. According to the U.S. Army Corps of Engineers, this trend is likely to continue in some capacity over the coming months with a lack of snowpack in much of the Northern Plains and Rocky Mountains. Just under 30% of the Missouri River Basin is in some form of drought, also contributing to a potential deficit when it comes to water levels in the coming months.

On a positive note, dry conditions across the Missouri River Basin are far better than this time last year, when over 65% of the basin was dealing with drought. Beyond that, March and April could still bring meaningful snowfall across northern parts of the basin. Even with current moisture deficits, the latest runoff forecast is projected to be around 91% of average, a manageable figure when it comes to making adjustments for navigation and water availability.

Looking ahead to spring, precipitation patterns could go in either a drier or wetter direction across different parts of the Missouri River Basin, including Northwest Missouri and Northeast Kansas. That being said, below average snowpack this late in the winter season could help reduce the risk for major flooding come spring-time, depending on how rainfall patterns shape up.