Flood Potential Outlook
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
963
FGUS73 KBIS 121716
ESFBIS
NDC001-007-011-015-021-025-029-031-033-037-041-043-045-047-051-053-
055-057-059-061-065-083-085-087-089-093-103-105-130130-
Probabilistic Hydrologic Outlook
National Weather Service Bismarck ND
1216 PM CDT Thu Mar 12 2026
...SPRING FLOOD AND WATER RESOURCES OUTLOOK...
This Spring Flood and Water Resources Outlook is for the Missouri
and James River basins of North Dakota, covering the period of 15
March through 13 June, 2026. This outlook is the last of the three
part series collectively referred to as the Spring Flood and Water
Resources Outlooks. On March 26th, the National Weather Service will
revert back to its normal issuance of the 90-day probabilistic
outlooks, usually on, or about the 4th Thursday of every month. In
reality, NWS-Bismarck uses the same general format for the routine
monthly Flood and Water Resources Outlooks as it does for this
nationally coordinated series of outlooks.
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...
In general, the models do not currently reflect much risk of
widespread flooding across the James and Missouri River basin
forecast locations. This is largely due to the current lack of snow
cover and recent gentle melt pattern across most of the James and
Missouri River basins of North Dakota. The risks presented in the
below tables are largely associated with the risk of an early,
large, spring rain on top of what are currently wet and frozen
soils. These wet and frozen soils impede infiltration of rain and
meltwater into the ground and enhance runoff from a given snowpack
or spring rain. Once the soils begin to thaw in earnest, the overall
risk for flooding will further lessen.
Lastly, warm weather will once again visit the area around the
middle of the third full week of March. While this certainly does
not suggest the area will not receive snow later this month, it will
very likely remove the snow received over the coming few days. It
should also start significantly thawing the ground surface,
especially in areas with little to no snow.
...Snowpack Conditions...
While the snow accumulation season had a robust beginning in early
December, most of the Missouri and James River basins have since
lost most of their snowpack to melting and sublimation. Much, but
not all, of this meltwater ran into the local streams and is now
drained off the countryside. There are a couple of chances for
precipitation over the coming few days, but not enough is expected
to substantially alter the below tables of probabilities.
...The Missouri and Yellowstone rivers west of Williston...
The Missouri and Yellowstone rivers west of Williston are generally
in the near normal range for this time of year. Runoff from the
intermittent melt pattern over the past several weeks has produced
modest amounts of runoff that continues to make its way towards Lake
Sakakawea. While flooding is not a large concern at this point,
unstable ice along the free-flowing portions of the Yellowstone and
Missouri Rivers west of Williston is a danger to outdoor enthusiasts
recreating on and along the rivers. As the area warms again in the
third full week of March, the ice on both the Yellowstone and
Missouri rivers west of Williston will become increasingly unstable.
...The Missouri River Below Garrison Dam...
The Missouri River below Garrison Dam is largely open down through
the Wilton area. From Wilton to the Bismarck/Mandan area, the ice
weakens with each passing day and the percentage of open water
increases. Given the weather forecast, the Missouri River near the
Bismarck and Mandan area is likely to lose its ice cover during the
third full week of March. Once this happens, the risk of an ice jam
will be all but zero.
...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, even as they have
taken on some runoff. Flood control features are already at, or
below their normal draw-down levels in preparation for the eventual
spring melt season. This suggests that local water storage will
provide a normal amount of flood mitigation through the spring melt
season. Many smaller water storage features, such as stock dams and
dugouts have already experienced considerable rises due to recent
runoff events.
...Soil Conditions...
Soil temperatures are highly varied this year. Soils are warming
fast in the southwest corner of North Dakota, but considerable frost
depth remains the farther east and north one looks.
Below freezing temperatures can go down to around 30 inches in some
areas, with about 24 inches being normal. These soil temperatures
are generally near normal for this time of year. What is quite a bit
more unusual is the soil moisture profile across the Missouri and
James River basins. Since the early snow fell on warm soils and
subsequently experienced a lot of melting, the ground surface and
near surface soils tend to be very wet. The very southwest portion
of the state is the exception to a wet ground surface as
unseasonably warm temperatures have at least dried out the surface
soils.
...Weather Outlook...
While the short-term forecast is generally cool and wet, the 6-10
outlooks favor above normal temperatures across North Dakota, but
the precipitation outlook favors below normal precipitation across
the southern one-third of the state, with areas north of that in the
James and Missouri River basins near normal. In the slightly longer
term, the 8-14 day weather outlooks retain the above normal
temperature signal, but the precipitation outlook slightly favors
above normal precipitation north of Highway 200, and near normal
precipitation south of Highway 200. The one-month outlook, covering
all of March, puts all of the state north of I-94 in the equal
chances designation for above normal, near normal, or below normal
temperatures, with south of I-94 slightly favored for above normal
temperatures. Nearly all of the James and Missouri basins with the
equal chances designation for above normal, near normal, or below
normal precipitation.
The longer term 3-month outlooks covering March, April, and May
has all of the James and Missouri River basins in the equal chances
category for above normal, near normal, or below normal temperatures
and precipitation.
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: 03/15/2026 - 06/13/2026
: 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 : 7 17 <5 8 <5 <5
:Missouri River
Williston 22.0 24.0 26.0 : 9 42 <5 25 <5 8
: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 : 16 58 <5 <5 <5 <5
:Beaver Creek
Linton 12.0 14.0 16.0 : 13 45 5 31 <5 13
:Little Muddy River
Williston 10.0 12.0 14.0 : 24 73 8 43 <5 10
:Little Missouri River
Marmarth 18.0 23.0 30.0 : <5 6 <5 <5 <5 <5
Medora 15.0 18.0 20.0 : 6 24 5 9 <5 6
Watford City 20.0 24.0 30.0 : 5 14 <5 5 <5 <5
:Knife River
Manning 15.0 17.0 20.0 : 10 26 <5 <5 <5 <5
:Spring Creek
Zap 14.0 18.0 20.0 : 9 31 6 17 5 8
:Knife River
Hazen 21.0 24.0 25.0 : 14 43 6 31 5 26
:Heart River
Mandan 27.0 33.0 38.0 : <5 17 <5 <5 <5 <5
:Apple Creek
Menoken 15.0 16.0 17.0 : 35 58 18 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: 03/15/2026 - 06/13/2026
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Pipestem
Pingree 5.3 5.3 5.3 5.4 5.8 8.7 9.4
:James River
Grace City 5.5 5.5 5.5 5.9 6.7 9.9 11.4
LaMoure 7.8 7.8 7.9 8.2 9.0 11.6 15.4
:Missouri River
Williston 17.0 17.8 18.1 18.7 19.7 21.4 23.3
:Cannonball River
Regent 5.2 5.3 5.8 7.0 8.0 8.8 9.0
:Cedar Creek
Raleigh 2.3 2.4 3.2 4.2 5.8 6.6 6.9
:Cannonball River
Breien 4.5 4.5 5.0 6.6 8.9 10.9 11.5
:Beaver Creek
Linton 5.6 5.7 6.4 8.6 10.4 12.3 13.8
:Little Muddy River
Williston 5.2 5.4 6.4 8.8 9.9 11.5 12.6
:Little Missouri River
Marmarth 1.4 1.4 2.1 4.8 9.7 13.1 16.5
Medora 3.7 3.7 4.3 5.7 10.4 13.3 17.2
Watford City 8.5 8.8 10.4 11.9 14.7 16.9 20.2
:Knife River
Manning 6.1 6.5 7.6 8.6 9.9 14.9 15.1
:Spring Creek
Zap 6.0 6.4 7.1 8.7 10.6 13.0 20.6
:Knife River
Hazen 4.0 5.0 6.3 9.2 14.7 23.2 24.9
:Heart River
Mandan 12.8 13.2 14.2 15.3 19.8 21.6 24.0
:Apple Creek
Menoken 7.6 8.3 9.9 13.3 15.7 16.8 17.0
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: 03/15/2026 - 06/13/2026
LOCATION 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Pipestem
Pingree 5.0 4.9 4.8 4.8 4.8 4.8 4.8
:James River
Grace City 4.4 4.4 4.3 4.3 4.2 4.2 4.2
LaMoure 7.3 6.9 6.5 6.5 6.5 6.5 6.5
:Missouri River
:Cannonball River
Regent 5.0 5.0 5.0 5.0 5.0 5.0 5.0
:Cedar Creek
Raleigh 1.1 1.1 1.1 1.0 1.0 0.8 0.8
:Cannonball River
Breien 2.4 2.4 2.2 2.2 2.1 2.1 2.1
:Beaver Creek
Linton 4.7 4.7 4.5 4.4 4.4 4.4 4.4
:Little Muddy River
Williston 4.7 4.6 4.5 4.5 4.5 4.5 4.4
:Little Missouri River
Marmarth 1.3 1.3 1.3 1.3 1.3 1.3 1.3
Medora 2.5 2.5 2.5 2.5 2.5 2.5 2.4
Watford City 8.4 8.3 8.3 8.3 8.2 8.2 8.2
:Knife River
Manning 6.1 6.1 6.1 6.1 6.0 6.0 6.0
:Spring Creek
Zap 4.8 4.8 4.7 4.7 4.7 4.7 4.7
:Knife River
Hazen 2.1 2.1 2.0 2.0 1.9 1.9 1.9
:Heart River
Mandan 11.2 11.2 11.1 11.1 11.0 10.9 10.9
:Apple Creek
Menoken 4.9 4.9 4.6 4.0 3.5 3.4 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 26 March.
$$
Schlag