Current Conditions for the Missouri River Basin

• According to the U.S. Drought Monitor, 17% of the area within Missouri River Basin states are in drought. Severe Drought (D2) persists in Kansas and Montana, with Extreme Drought (D3) impacting small portions of western Montana and central Kansas. 
• Despite the remaining drought in some areas, conditions improved in many areas of the basin over the spring season (Figure 1). North Dakota, Iowa, Missouri, and parts of Montana saw the most improvement this spring. 
• Above-normal spring precipitation drove this improvement in many areas (Figure 2). Iowa, North Dakota, and northern Montana received 100–200% of normal precipitation over the past 90 days. 
• However, portions of Kansas, eastern Colorado, eastern Wyoming, eastern Montana, and portions of the Dakotas received only 5–50% of normal precipitation. Some of the largest deficits were in Kansas and eastern Colorado, where drought conditions worsened.
• Despite above-normal spring precipitation in many areas, the snowfall season was below-normal for a majority of the basin. Snowfall since September 1, 2023 is only 25-75% of normal for North Dakota, South Dakota, and eastern Wyoming (Figure 3). 

Figure 1: 10-Week U.S. Drought Monitor Change Map (Since March 12, 2024)

Key Takeaway: Much of the Missouri River Basin saw drought improvement throughout the spring. Areas with drought improvement include northern South Dakota, eastern Nebraska, and nearly all of Montana, North Dakota, Missouri, and Iowa. Drought conditions deteriorated in eastern Colorado and in Kansas throughout the spring. 

Figure 2: 90-Day Percent of Normal Precipitation (February 23–May 22, 2024)

Key Takeaway: recipitation totals were mixed across the Missouri River Basin over the last 90 days. Northern Montana, northern North Dakota, and western Iowa received significantly above-average precipitation. Below-normal precipitation was widespread across Kansas, western Nebraska, eastern Wyoming, and eastern Colorado.

Figure 3: Percent of Normal Snowfall from September 1, 2023–May 23, 2024

Key Takeaway: Snowfall was below normal across the majority of the Missouri River Basin, most significantly across, North Dakota, South Dakota, Missouri, and eastern Wyoming. 

Missouri River Basin Drought Impacts

• Below-normal snowfall during the winter, across the region, caused negative impacts for recreation industries. Impacts included navigation issues, low water levels on recreational lakes, and concern for harmful algal blooms. 
• Below-normal mountain snowpack reduced the risk for spring flooding in Upper Missouri, but this also meant less replenishment of overall moisture to the system (e.g., soil moisture, groundwater), which typically happens during the snowmelt season in late winter and spring.
• The river runoff forecast for the Missouri River Basin is still below normal, due to low snowpack in the headwaters, and reservoir systems continue to release water to meet downstream navigational targets. 
• Poor precipitation timing throughout the winter and spring and the resulting drought negatively impacted western Kansas winter wheat. Current wheat conditions in Kansas are reporting for the sixth week in a row as the worst in the United States.  
• For the first time in two years, rainfall-driven river flooding was seen in the lower basin in eastern Kansas, western Missouri, and northwestern Iowa, as drought conditions slowly improved across parts of the basin throughout the month of May. 
• Surface water and soil moisture conditions improved throughout the spring season in most of the basin as a result of timely spring rains (Figures 4, 5). 

Figure 4: 28-Day Average Streamflow Conditions (Valid May 22, 2024)

Key Takeaway: Wet spring conditions resulted in average to above-average streamflow conditions across the basin, except in central and southwestern Kansas, where persistent drought conditions this spring resulted in below-normal streamflow.

Figure 5: 0–100 cm Soil Moisture Conditions (Valid May 22, 2024)

Key Takeaway: Wet spring conditions resulted in a recovery of soil moisture conditions across much of the basin, resulting in near to above-normal conditions across many areas. However, persistent drought conditions this spring have resulted in below-normal soil moisture conditions across eastern Colorado, and southern Wyoming, and western Kansas.

Figure 6: Stock Ponds in North Dakota: April 15 vs. May 20

Key Takeaway: Regular spring rainfall over the northern Great Plains reduced drought impacts from below-normal snowfall during the winter season and allowed surface water conditions to recover. 

Outlooks and Potential Impacts for the Missouri River Basin

• The NOAA Climate Prediction Center’s summer outlook for June–August 2024 shows an increased chance of above-normal temperatures across large portions of the basin, except for North Dakota, South Dakota, and western portions of Iowa, which have equal chances for above-, near-, or below-normal temperatures (Figure 7). 
• The next three months (June–August) have almost equal chances of neutral or La Niña conditions, but La Niña is expected to develop in the Pacific Ocean by late summer/early fall. During the neutral summer months, forecasters expect that there will be less predictability of precipitation.
• Western portions of the basin have a higher probability of below-normal precipitation, while eastern basin states have equal chances for above-, near-, or below-normal precipitation (Figure 8). Combined with above-normal temperatures, low precipitation could mean lower streamflows and reduced soil moisture. The combination of hot and dry weather may lead to negative agricultural impacts throughout the summer. 
• Through the end of August, the Climate Prediction Center's seasonal drought outlook calls for drought to persist in areas already in drought in western Kansas and portions of Montana and Wyoming, with the possibility of drought improvements in Iowa. The majority of the basin is not predicted to see drought develop, though as summer temperatures increase, the possibility of flash drought development is still present (Figure 9).

Figure 7: Seasonal Temperature Outlook for (June–August 2024)

Key Takeaway: Temperatures are likely to be above normal across large portions of the Missouri River Basin from June–August 2024. The greatest chances of above-normal temperatures are in western portions of Montana, Wyoming, and Colorado. North Dakota, South Dakota, and portions of Minnesota and Iowa have equal chances for above-, near-, or below-normal temperatures.

Figure 8: Seasonal Precipitation Outlook (June–August 2024)

Key Takeaway: Below-normal precipitation is anticipated across Montana, Wyoming, Colorado, and western portions of South Dakota, Kansas, and Nebraska for June through August 2024. The rest of the basin has equal chances for above-, near-, or below-normal precipitation.

Figure 9: Seasonal Drought Outlook (Valid May 16–August 31, 2024)

Key Takeaway:  Drought is expected to persist or develop in parts of Kansas, Wyoming, Montana, and Nebraska through the end of August. Areas of remaining drought in Nebraska and Iowa after spring improvements are expected to improve or be removed during the summer months. No drought development is forecasted for the remainder of the basin.