Flood Potential Outlook
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
878
FGUS73 KBIS 121833
ESFBIS
NDC001-007-011-015-021-025-029-031-033-037-041-043-045-047-051-053-
055-057-059-061-065-083-085-087-089-093-103-105-130245-
Probabilistic Hydrologic Outlook
National Weather Service Bismarck ND
1233 PM CST Thu Feb 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
February through 16 May, 2026. This outlook is the first of three in
a series of outlooks that the National Weather Service collectively
refers to as the Spring Flood and Water Resources Outlooks. This
will be followed by Spring Flood and Water Resources Outlooks to be
issued on 26 February, and 12 March, 2026. 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.
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 current models do not have much risk of widespread
flooding across the James and Missouri River basin forecast
locations. This is largely due to the widespread runoff that
occurred during early February. This runoff event drained a large
fraction of the modest Snow-Water Equivalent (SWE) that was sitting
on the ground surface since early December. Accordingly, the
hydrologic models recognize that the region may now be only several
weeks away from the spring melt season and it is unlikely we will
see the accumulation of two plus inches of SWE across large areas.
However, while the risk is currently low in the models, the runoff
event experienced in early February made the most of what was
already a very limited snowpack and due to its quick nature, frozen
ground surface, and roughly 0.75-1.25 inches of SWE in the ice and
snow cover, some fairly impressive rises were observed in the
streams of western North Dakota. So, while the snowpack is currently
insufficient to generate much concern...there remains a distinctly
non-zero risk of flooding, especially if the region were to
experience a warm Colorado Low bringing heavy spring rains before
the soils thaw and become available to infiltration of meltwater and
rainfall.
...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 much of their snowpack to melting and sublimation. Much of this
meltwater ran into the local streams and are still draining it off
of the countryside. In the southwestern corner of the state, SWE
content is now well below one-half of an inch, and builds slightly
to around one inch in the upper James River Basin. In and of itself,
the existing snowpack does not create much concern, but with several
weeks remaining in the snow accumulation season, it remains to be
seen how much total SWE will be on the ground for the eventual
spring melt season. Totals of over two inches of SWE across large
areas would be cause for concern this year given the demonstrated
impermeable nature of the surface soils.
...The Missouri and Yellowstone rivers west of Williston...
The Missouri and Yellowstone rivers west of Williston are slightly
elevated for this time of year as runoff from the early February
melt continues making 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.
...The Missouri River Below Garrison Dam...
The Missouri River below Garrison Dam is largely open down to about
Washburn. From Washburn to the Bismarck/Mandan area, there are a few
spots showing open water but it generally remains covered in ice.
This suggests that even with seasonable temperatures, enough ice
remains on the Missouri River to produce ice jam(s) if the region
were to experience a sudden large runoff event. For example, a warm
Colorado Low storm system bringing excessive rainfall to the area
before the soils thaw sufficiently to restore the soil`s ability to
minimize runoff, would be such an event.
...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 reservoir are generally within the
long-term normal range for this time of the year. Flood control
features are already at 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 come the
spring melt season. Many smaller water storage features, such as
stock dams and dugouts have already experienced considerable rises
due to the February melting off of the local snowpack.
...Soil Conditions...
Soil temperatures are highly varied this year. In places where the
snow largely melted off during the multiple warm periods in late
December, early January and again in early February are now poorly
insulated and this helps frost depths increase. 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 profiles across the Missouri and James River
basins. Since the early snow fell on warm soils and subsequently
experienced a lot of melting without generating much observed
runoff, that water infiltrated into the soil and generally remains
trapped in the upper four inches of the ground. This has created a
nearly impermeable surface to the ground which has the potential to
greatly enhance future runoff from a given melting snowpack or early
spring rains.
Weather Outlook...
The near-term 6-10 and 8-14 day weather outlooks favor an above
normal temperature in the earlier portion of the next two weeks
coupled with an above normal favoring for above normal
precipitation. The temperature portion of this wanes a bit towards
the end suggesting a change in patterns that will bring cooler than
normal air into the region for the last 10 days of February while
retaining the above normal precipitation expectation.
For the full month of February, the western half of North Dakota is
in the equal chances designation for below normal, near normal, or
above normal temperatures with a slight favoring for below normal
temperatures in the eastern half of the state while nearly the
entire state of North Dakota is slightly favored for above normal
precipitation.
Looking even longer term, the 3-month outlooks covering February,
March, and April favor below normal temperatures with a slight
favoring of above normal precipitation. These outlooks remain
consistent with historical trends for the area when under a La Nina
influenced climate pattern. Note, the existing La Nina is expected
to wane over the coming weeks and months, but the reality is that
local weather patterns have not been very reflective of La Nina
affected weather patterns since before Christmas.
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: 02/15/2026 - 05/16/2026
: 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 : 6 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 : <5 20 <5 8 <5 5
: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 : 13 55 <5 <5 <5 <5
:Beaver Creek
Linton 12.0 14.0 16.0 : 19 41 <5 28 <5 13
:Little Muddy River
Williston 10.0 12.0 14.0 : 9 60 <5 33 <5 10
:Little Missouri River
Marmarth 18.0 23.0 30.0 : <5 <5 <5 <5 <5 <5
Medora 15.0 18.0 20.0 : <5 15 <5 8 <5 <5
Watford City 20.0 24.0 30.0 : <5 13 <5 <5 <5 <5
:Knife River
Manning 15.0 17.0 20.0 : 6 20 <5 <5 <5 <5
:Spring Creek
Zap 14.0 18.0 20.0 : 8 22 5 14 <5 8
:Knife River
Hazen 21.0 24.0 25.0 : 8 40 7 25 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 : 49 55 25 52 9 31
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:
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Pipestem
Pingree 4.9 4.9 4.9 5.1 5.9 8.2 10.0
:James River
Grace City 4.0 4.0 4.0 4.8 6.3 9.4 13.0
LaMoure 7.0 7.0 7.1 7.6 9.5 11.6 14.1
:Missouri River
Williston 15.5 15.8 16.1 16.6 17.9 18.6 20.7
:Cannonball River
Regent 5.2 6.0 6.4 6.8 7.6 9.0 10.1
:Cedar Creek
Raleigh 2.2 2.7 3.4 4.5 5.8 6.5 6.7
:Cannonball River
Breien 3.4 4.4 5.6 6.8 8.8 10.7 11.5
:Beaver Creek
Linton 4.8 6.0 7.0 8.2 10.8 12.2 13.2
:Little Muddy River
Williston 4.7 4.8 5.5 5.9 7.5 9.7 11.9
:Little Missouri River
Marmarth 1.5 1.5 2.3 4.7 6.9 11.5 12.7
Medora 4.3 4.3 4.6 5.5 9.1 13.7 14.4
Watford City 8.7 8.7 10.3 11.3 13.7 17.4 18.9
:Knife River
Manning 6.2 6.9 7.1 8.0 9.4 14.9 15.1
:Spring Creek
Zap 5.1 5.5 6.4 7.3 9.3 12.6 17.8
:Knife River
Hazen 1.5 4.0 6.3 9.2 14.0 17.9 25.2
:Heart River
Mandan 10.8 12.7 13.6 15.8 19.4 22.0 24.7
:Apple Creek
Menoken 6.0 6.6 10.4 14.9 16.0 16.9 17.7
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: 02/15/2026 - 05/16/2026
LOCATION 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Pipestem
Pingree 4.8 4.8 4.8 4.7 4.7 4.7 4.7
:James River
Grace City 4.0 4.0 4.0 4.0 4.0 4.0 4.0
LaMoure 7.0 6.9 6.9 6.8 6.7 6.7 6.7
:Missouri River
:Cannonball River
Regent 4.9 4.9 4.9 4.9 4.8 4.8 4.8
:Cedar Creek
Raleigh 0.8 0.8 0.7 0.6 0.6 0.5 0.4
:Cannonball River
Breien 2.0 2.0 2.0 2.0 1.9 1.8 1.8
:Beaver Creek
Linton 4.5 4.5 4.5 4.4 4.4 4.4 4.3
:Little Muddy River
Williston 4.5 4.5 4.5 4.5 4.5 4.5 4.4
:Little Missouri River
Marmarth 1.3 1.2 1.2 1.2 1.2 1.2 1.2
Medora 2.2 2.2 2.0 2.0 2.0 2.0 2.0
Watford City 7.5 7.5 7.5 7.5 7.4 7.4 7.4
:Knife River
Manning 6.2 6.2 6.1 6.1 6.1 6.1 6.1
:Spring Creek
Zap 4.7 4.7 4.7 4.7 4.7 4.7 4.6
:Knife River
Hazen 1.0 1.0 0.9 0.9 0.9 0.9 0.8
:Heart River
Mandan 9.6 9.6 9.6 9.4 9.2 9.1 9.0
:Apple Creek
Menoken 5.2 5.2 5.2 5.2 5.2 5.2 5.2
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 February.
$$
Schlag