Ag Weather Forum

Judging by the latest runoff forecast for the Upper Missouri River Basin from the U.S. Army Corps of Engineers (USACE), soil moisture prospects for the northwestern Corn Belt are on the dry side as we move further into spring 2025.

The USACE's latest 2025 calendar year runoff forecast for the Missouri River Basin above Sioux City, Iowa, showed that March runoff in the Upper Missouri Basin was 2.3 million acre-feet (MAF), just 76% of average.

"We are forecasting a below-average runoff year for the basin," said USACE Missouri River Basin Water Management Division Chief John Remus in a USACE news release.

The update noted the 2025 calendar year runoff forecast above Sioux City is 21.9 MAF, 85% of average. The runoff forecast is based on current soil moisture conditions, Plains snowpack, mountain snowpack, and long-term precipitation and temperature outlooks.

As of early April, the water volume stored in the Missouri River Mainstem Reservoir System was noted at 50.8 MAF, 5.3 MAF below the top of the carryover multiple use zone.

The contribution of moisture from snow melt into the river basin is also below average. As of Wednesday, April 16, the Snow Water Equivalent (SWE) amount was 85% of the 30-year average in the reach above Fort Peck, Montana. The Fort Peck to Garrison, North Dakota, reach SWE was also 85% of the 30-year average. The typical peak date for SWE in both reaches is April 17, which indicates that both reaches will finish the season with below-average snow melt water moving into these stretches of the Upper Missouri River.

Snowfall at reporting stations on the Upper Missouri is notably below average. On the river reach above Fort Peck, total snowfall at the Glasgow, Montana, National Weather Service office from July 1, 2024, was 21.0 inches on Monday, April 21, 2025 -- just 53% of the average 39.3 inches. Since March 1, 2025, the Glasgow NWS office has recorded just 1.8 inches of snow, only 24% of the average 7.6 inches. Further downstream in North Dakota, the Bismarck NWS station has logged 25.3 inches of snow since July 1, 2024 -- just 51% of the average 49.3 inches. Since March 1, 2025, Bismarck has had only 3.8 inches of snow, 31% of the average 12.3 inches. Soil moisture assessments in the Dakotas and Montana are also mostly short to very short, particularly in South Dakota, with topsoil moisture assessed at 80% short to very short and subsoil moisture assessed at 90% short to very short in the April 21, 2025, USDA NASS Crop Progress report.

Forecast precipitation over the next week offers some moisture with scattered benefits for the upper reaches of the Missouri Basin. That may offer short-term soil moisture, but the region begins planting season on the short side when it comes to precipitation ahead of substantial need and usage.

Bryce Anderson can be reached at bryce.anderson@dtn.com

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