Flood Potential Outlook
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
597
FGUS73 KBIS 271907
ESFBIS
NDC001-007-011-015-021-025-029-031-033-037-041-043-045-047-051-053-
055-057-059-061-065-083-085-087-089-093-103-105-291800-
Probabilistic Hydrologic Outlook
National Weather Service Bismarck ND
207 PM CDT Fri Jun 27 2025
...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 28
June through 28 September, 2025.
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 majority of forecast locations in the Missouri and
James River basins across North Dakota are near to somewhat below
normal for this time of year.
...Snowpack Conditions...
No snow exists in the Missouri and James River basins of North
Dakota.
...The Missouri and Yellowstone rivers west of Williston...
The headwaters areas for both the Yellowstone and Missouri rivers
continue to melt off a near-normal snowpack, but the overall runoff
remains somewhat lower than normal this year.
...Current Drought Conditions...
Recent rainfall has been very beneficial and improved the conditions
that influence drought designations. Nonetheless, there are still D0
(Abnormally Dry) to D1 (Moderate Drought) conditions that remain
over a fairly large area of western North Dakota centered around
McKenzie, Dunn, Gollden Valley and Billings counties. This area,
while significantly better off than just a few short weeks ago,
continues to reflect a less than optimal rebound from the much more
severe dry conditions over the past year.
...Reservoirs and Natural Wetlands...
In general, the Missouri River reservoirs of Lake Oahe and Lake
Sakakawea remain at the lower end of normal for expectations this
year. Smaller man-made features,natural wetlands, and livestock
dams have experienced mixed results with some doing well, and others
well below normal for this time of year.
...Soil Conditions...
A higher than normal fraction of the recent heavy rains infiltrated
the soil and raised soil moisture values considerably. Indeed, much
of the Missouri and James basins now have above normal soil moisture
values for this time of year.
...Weather Outlook...
The near term 6-10 and 8-14 day weather outlooks favor above normal
temperatures with above normal to below normal precipitation across
North Dakota. The outlooks for the month of July have a fairly
strong favoring for above above normal temperatures with below
normal precipitation. Looking our even longer at the three-month
outlooks covering July, August and September there is again a fairly
strong favoring for above normal temperatures with below normal
precipitation. This favoring of above normal temperatures and below
normal precipitation signal during the middle to latter half of
summer have been consistent now for several months.
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: 06/28/2025 - 09/26/2025
: 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 5 <5 <5 <5 <5
:James River
Grace City 12.0 14.0 15.0 : 11 8 9 7 8 6
LaMoure 14.0 16.0 18.0 : 5 <5 <5 <5 <5 <5
:Missouri River
Williston 22.0 24.0 26.0 : <5 38 <5 28 <5 14
: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 <5 <5 <5 <5 <5
:Cannonball River
Breien 10.0 20.0 23.0 : 9 34 <5 <5 <5 <5
:Beaver Creek
Linton 12.0 14.0 16.0 : 8 22 6 13 5 11
:Little Muddy River
Williston 10.0 12.0 14.0 : 11 40 5 17 <5 5
:Little Missouri River
Marmarth 18.0 23.0 30.0 : <5 <5 <5 <5 <5 <5
Medora 15.0 18.0 20.0 : <5 <5 <5 <5 <5 <5
Watford City 20.0 24.0 30.0 : <5 <5 <5 <5 <5 <5
:Knife River
Manning 15.0 17.0 20.0 : 6 13 <5 5 <5 <5
:Spring Creek
Zap 14.0 18.0 20.0 : 14 13 7 12 5 11
:Knife River
Hazen 21.0 24.0 25.0 : 15 12 10 10 6 9
:Heart River
Mandan 27.0 33.0 38.0 : 8 9 <5 <5 <5 <5
:Apple Creek
Menoken 15.0 16.0 17.0 : 19 40 12 27 5 9
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: 06/28/2025 - 09/26/2025
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Pipestem
Pingree 5.4 5.4 5.4 5.6 6.4 9.7 11.1
:James River
Grace City 6.4 6.4 6.4 6.4 7.8 12.7 17.2
LaMoure 8.1 8.1 8.1 8.1 8.2 9.2 13.4
:Missouri River
Williston 16.8 16.8 16.8 16.8 16.8 18.2 18.8
:Cannonball River
Regent 5.3 5.3 5.6 6.5 7.4 8.3 8.9
:Cedar Creek
Raleigh 1.4 1.5 2.6 3.9 4.7 5.7 6.6
:Cannonball River
Breien 3.2 3.9 4.9 6.4 8.0 9.7 11.3
:Beaver Creek
Linton 4.6 4.7 5.0 5.2 6.9 9.6 15.5
:Little Muddy River
Williston 4.6 4.6 4.7 4.9 6.9 10.9 12.1
:Little Missouri River
Marmarth 1.2 1.2 1.2 1.2 4.0 7.3 8.1
Medora 2.2 2.2 2.2 2.2 4.7 7.6 8.9
Watford City 7.5 7.5 7.5 8.2 10.1 12.4 13.5
:Knife River
Manning 6.2 6.2 6.3 7.2 8.4 13.8 15.8
:Spring Creek
Zap 4.7 4.7 4.7 5.2 8.4 15.0 20.1
:Knife River
Hazen 1.2 1.2 1.2 4.2 11.3 24.2 25.1
:Heart River
Mandan 9.6 9.6 10.6 12.3 17.5 21.2 31.0
:Apple Creek
Menoken 6.4 6.4 6.5 8.2 14.5 16.1 17.3
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: 06/28/2025 - 09/26/2025
LOCATION 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Pipestem
Pingree 5.4 5.4 5.3 5.3 5.3 5.3 5.3
:James River
Grace City 4.8 4.5 4.4 4.3 4.3 4.3 4.3
LaMoure 7.6 7.5 7.4 7.1 7.1 7.1 7.1
:Missouri River
:Cannonball River
Regent 5.2 5.2 5.2 5.2 5.2 5.2 5.2
:Cedar Creek
Raleigh 1.3 1.2 1.2 1.2 1.2 1.2 1.2
:Cannonball River
Breien 2.3 2.2 2.2 2.1 2.1 2.1 2.1
:Beaver Creek
Linton 4.6 4.5 4.4 4.3 4.3 4.3 4.3
:Little Muddy River
Williston 4.6 4.6 4.6 4.6 4.6 4.6 4.6
:Little Missouri River
Marmarth 1.1 1.0 1.0 1.0 1.0 0.9 0.9
Medora 2.0 2.0 2.0 2.0 2.0 2.0 2.0
Watford City 7.4 7.3 7.2 7.1 7.1 7.1 7.1
: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 4.7
:Knife River
Hazen 1.0 0.9 0.9 0.8 0.8 0.7 0.7
:Heart River
Mandan 9.3 9.2 9.2 9.1 9.1 9.1 9.0
:Apple Creek
Menoken 6.3 6.3 6.2 6.2 6.2 6.2 6.2
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 by the end of July.
$$
Schlag