FGUS73 KBIS 261721 ESFBIS NDC001-007-011-015-021-025-029-031-033-037-041-043-045-047-051-053- 055-057-059-061-065-083-085-087-089-093-103-105-270130- Probabilistic Hydrologic Outlook National Weather Service Bismarck ND 1221 PM CDT Thu Mar 26 2026 ...FLOOD AND WATER RESOURCES OUTLOOK... This Flood and Water Resources Outlook is for the Missouri and James River basins of North Dakota, covering the period of March 29th through June 27th, 2026. The following message has four sections. The first provides some text on the highlights of this outlook and conditions affecting the local hydrology. The second section gives the current and historical risks of flooding as determined by the Ensemble Streamflow Forecast model of the National Weather Service. The third section gives the current probabilities for reaching flood stage at the listed forecast locations. And finally, the fourth section covers the risk of the river sites falling below the listed stages. ...Flood Outlook Highlights... The overall probability of widespread flooding across the Missouri and and James River basins is seasonably low for this outlook period. This is a result of the lack of snowcover as of late March, and the continued thawing of soils. Earlier-season snowfall and recent light snow events have produced some runoff that has already made its way through creeks and streams with little fanfare outside of early-season, within-bank rises. Ice is now out of many creeks and rivers, and will continue to thaw and break up in others, along with area lakes and reservoirs in the coming weeks. This means the risk of ice-jam related flooding has also diminished. Despite the lack of snowcover, soils are wet across much of the James and Missouri River basins, outside of far southwest North Dakota. As a result, if a heavy snow or heavy rain event was to occur, it could generate enough runoff to cause increased flows on creeks and streams. That scenario accounts for the low probability of flooding that exists in the flood outlook probabilities. The outlook already accounts for both current soil moisture conditions and the historical frequency of springtime rain and snow events, and generally reflects an overall below-normal risk of flooding due the lack of snowcover and thawing soils. ...Snowpack Conditions... Snowcover is not present in either the Missouri or James River basins in North Dakota as of late March. Earlier-season snowpack melted with stretches of warm weather after the 1st of the year, and either ran off into local streams or infiltrated soils. The result has been wet soils in many portions of the Missouri and James River basins. As is always the case this time of the year, additional snowfall may still occur, which could result in short-term snowmelt runoff yet this spring. The probabilities in this flood outlook already account for the historical frequency and probability of those potential snow events. ...Current Drought Conditions... There are no current drought designations in the Missouri and James River basins of North Dakota. ...Reservoirs and Natural Wetlands... Natural wetlands and artificial reservoirs are generally within the long-term normal range for this time of the year. Flood control features are generally at their normal spring draw-down levels. This suggests that local water storage will provide a normal amount of flood mitigation this spring. ...Soil Conditions... Soils have been warming through the last few weeks, though a stretch of colder weather in mid March slowed the progression of thawing in parts of the area. The southwest corner of North Dakota has had the warmest weather, and frost has gone out there with soil temperatures above freezing throughout the entire top 40 inches of the soil profile. Across northwest and central North Dakota into the James River Valley, there is more variability with regard to how deep the above-freezing layer has progressed into the soils, ranging from as little as 8 inches to as much as 20 inches. However, this is within the normal range for this time of the year, and the soils are expected to continue thawing going into early April. Soils across much of the Missouri and James River basins in North Dakota remain very wet. This is the result of early-winter snowfall on warm soils that caused considerable melting, and also the melting of that snowpack and additional light precipitation events the last few months. The exception to the wet soils is in the very southwest part of the state, where above normal temperatures have continued to dry out the soils in recent weeks. ...Weather Outlook... The short term weather forecast calls for warm and mainly dry weather to close out the month of March, but the 6-10 and 8-14 day outlooks favor above normal precipitation probabilities for North Dakota in early April. The overall weather pattern will begin to favor cooler temperatures, as well, especially in northern parts of the state in the 6-10 and 8-14 day period. Looking further out, when considering the outlook for the full month of April, there are equal chances of above-normal, near-normal, or below-normal temperatures and precipitation. This ultimately suggests that a relatively normal spring weather pattern featuring large variability is highly probable. That includes the aforementioned potential for a wetter and cooler start to April. Looking even longer term, the 3-month outlook covering April, May, and June has almost all of the Missouri and James River basins in equal chances for above-normal, near-normal, or below-normal temperatures and precipitation. The exception is the southwestern corner of North Dakota, which favors above-normal temperatures in that 3-month period. This is consistent with historical trends for the area as a La Nina pattern fades through the spring. In Table 1 below, the current (CS) and historical (HS) or normal probabilities of exceeding minor...moderate...and major flood stage are listed for the valid time period. CS values indicate the probability of reaching a flood category based on current conditions. HS values indicate the probability of reaching a flood category based on historical or normal conditions. When the value of CS is greater than HS...the probability of exceeding that level is higher than normal. When the value of CS is less than HS...the probability of exceeding that level is lower than normal. ...Table 1--Probabilities for minor...moderate and major flooding... Valid Period: 3/29/2026 - 6/27/2026 : Current and Historical : Chances of Exceeding : Flood Categories : as a Percentage (%) Categorical : Flood Stages (FT) : Minor Moderate Major Location Minor Mod Major : CS HS CS HS CS HS -------- ----- ----- ----- : --- --- --- --- --- --- :Pipestem Pingree 11.0 13.0 15.0 : <5 12 <5 <5 <5 <5 :James River Grace City 12.0 14.0 15.0 : <5 16 <5 13 <5 9 LaMoure 14.0 16.0 18.0 : <5 17 <5 8 <5 <5 :Missouri River Williston 22.0 24.0 26.0 : 6 42 <5 31 <5 9 :Cannonball River Regent 22.0 24.0 26.0 : <5 <5 <5 <5 <5 <5 :Cedar Creek Raleigh 12.0 14.0 16.0 : <5 9 <5 5 <5 <5 :Cannonball River Breien 10.0 20.0 23.0 : 11 52 <5 <5 <5 <5 :Beaver Creek Linton 12.0 14.0 16.0 : 5 44 <5 31 <5 13 :Little Muddy River Williston 10.0 12.0 14.0 : 13 69 <5 27 <5 7 :Little Missouri River Marmarth 18.0 23.0 30.0 : <5 6 <5 <5 <5 <5 Medora 15.0 18.0 20.0 : 5 21 <5 8 <5 6 Watford City 20.0 24.0 30.0 : <5 11 <5 5 <5 <5 :Knife River Manning 15.0 17.0 20.0 : <5 20 <5 <5 <5 <5 :Spring Creek Zap 14.0 18.0 20.0 : 8 22 5 11 <5 8 :Knife River Hazen 21.0 24.0 25.0 : 6 37 <5 28 <5 20 :Heart River Mandan 27.0 33.0 38.0 : <5 17 <5 <5 <5 <5 :Apple Creek Menoken 15.0 16.0 17.0 : 20 61 17 55 <5 34 Legend CS = Conditional Simulation (Current Outlook) HS = Historical Simulation FT = Feet In Table 2 below...the 95 through 5 percent columns indicate the probability of exceeding the listed stage levels (FT) for the valid time period. ...Table 2--Exceedance Probabilities... Chance of Exceeding Stages at Specific Locations Valid Period: 3/29/2026 - 6/27/2026 Location 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Pipestem Pingree 7.5 7.5 7.5 7.5 7.8 8.3 9.2 :James River Grace City 5.2 5.2 5.2 5.3 6.6 7.5 8.2 LaMoure 8.2 8.2 8.2 8.2 8.9 10.0 12.4 :Missouri River Williston 16.8 17.3 17.4 17.7 18.8 21.0 22.4 :Cannonball River Regent 5.3 5.3 5.9 6.8 7.6 8.5 9.2 :Cedar Creek Raleigh 1.1 1.2 2.3 3.7 5.0 6.2 6.7 :Cannonball River Breien 2.7 2.8 4.7 6.2 8.1 10.1 10.6 :Beaver Creek Linton 4.7 4.7 4.9 5.5 6.8 10.5 12.0 :Little Muddy River Williston 4.6 4.6 4.6 7.8 9.3 10.1 11.7 :Little Missouri River Marmarth 0.7 0.7 0.7 2.5 8.0 11.1 14.2 Medora 2.4 2.4 2.6 4.0 8.8 11.9 14.9 Watford City 8.2 8.2 8.8 10.3 13.3 15.3 18.4 :Knife River Manning 6.1 6.1 7.1 8.2 8.9 11.8 12.8 :Spring Creek Zap 4.8 4.8 6.1 7.8 9.4 11.3 18.7 :Knife River Hazen 2.0 2.0 4.5 7.1 11.4 17.1 22.7 :Heart River Mandan 11.7 12.0 12.9 15.1 18.3 20.9 24.1 :Apple Creek Menoken 6.2 6.2 6.9 12.4 14.5 16.5 16.7 In Table 3 below...the 95 through 5 percent columns indicate the probability of falling below the listed stage levels (FT) for the valid time period. ...Table 3--Nonexceedance Probabilities... Chance of Falling Below Stages at Specific Locations Valid Period: 3/29/2026 - 6/27/2026 LOCATION 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Pipestem Pingree 6.8 6.7 6.7 6.7 6.7 6.7 6.7 :James River Grace City 4.4 4.3 4.3 4.3 4.3 4.3 4.3 LaMoure 7.8 7.8 7.7 7.7 7.7 7.7 7.7 :Missouri River :Cannonball River Regent 5.2 5.2 5.2 5.2 5.2 5.2 5.2 :Cedar Creek Raleigh 0.4 0.4 0.4 0.4 0.4 0.4 0.4 :Cannonball River Breien 2.3 2.2 2.2 2.1 2.1 2.1 2.0 :Beaver Creek Linton 4.4 4.4 4.4 4.4 4.3 4.3 4.3 :Little Muddy River Williston 4.5 4.5 4.5 4.5 4.4 4.4 4.4 :Little Missouri River Marmarth 0.7 0.7 0.7 0.7 0.7 0.7 0.7 Medora 2.3 2.3 2.3 2.3 2.3 2.3 2.2 Watford City 8.2 8.2 8.2 8.1 8.1 8.1 8.1 :Knife River Manning 6.1 6.1 6.1 6.1 6.0 6.0 6.0 :Spring Creek Zap 4.7 4.7 4.7 4.7 4.7 4.7 4.7 :Knife River Hazen 2.0 2.0 2.0 1.9 1.9 1.9 1.9 :Heart River Mandan 11.4 11.3 11.2 10.9 10.8 10.8 10.8 :Apple Creek Menoken 4.2 4.2 4.0 3.8 3.4 3.3 3.3 These long-range probabilistic outlooks contain forecast values that are calculated using multiple season scenarios from 30 or more years of climatological data...including current conditions of the river...soil moisture...snow cover and 30 to 90 day long-range outlooks of temperature and precipitation. By providing a range of probabilities...the level of risk associated with long-range planning decisions can be determined. These probabilistic forecasts are part of the National Weather Service's Advanced Hydrologic Prediction Service. Visit our web site weather.gov/bis for more weather and water information. The next outlook will be issued by the end of April. $$ CJS