Flood Potential Outlook
Issued by NWS Duluth, MN
Issued by NWS Duluth, MN
Versions:
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FGUS73 KDLH 271545
ESFDLH
MNC001-017-021-031-035-061-071-075-115-137-WIC003-007-013-031-051-
099-113-129-280345-
Probabilistic Hydrologic Outlook
National Weather Service Duluth MN
945 AM CST Thu Feb 27 2025
...Spring Flood and Water Resources Outlook Number Two...
This outlook covers NE Minnesota and NW Wisconsin for river forecast
points on the headwaters of the Mississippi, Chippewa, St. Croix,
Rainy, and Knife Rivers.
...Current Conditions...
Most river basins have a normal to below normal amount of water in
the snowpack. Some areas along the North Shore have normal to above
normal snowwater. Drought conditions persist in the region due to
well below normal precipitation since July. Fall rains slightly
improved the drought condition in November. Precipitation since
October 1st is near normal. The ground is deeply frozen due to
frequent cold snaps and shallow snow depth. This is a key factor in
this Spring`s flood potential. Rivers are ice covered which could
be a factor in ice jam flooding.
Recent warm temperatures and strong winds have diminished snow
pack across the region. While the headwaters of the Mississippi
and Rainy basins have retained snow the Chippewa River headwaters
are seeing some snow melt runoff. Rivers and streams feeding Lake
Superior are also showing signs of snow melt runoff with many
rivers showing water flowing over ice. The Knife River near Two
Harbors is a good example. Melt is mainly occurring in the lower
terrain along the North Shore. Active melt has been observed in
all of northwest Wisconsin and areas south of Highway 2 in north
central Minnesota.
...Climate Outlook...
Through March 6th expect some additional snow on Friday February
28th mainly across the Minnesota Arrowhead and northern Wisconsin. The
eastern most portions of the Rainy River Basin and tip of the
Minnesota Arrowhead have the best chance to see storm water
equivalents of 0.25 inches or greater. The Climate Prediction
Center`s 2 week outlooks show above normal temperatures and near
to above normal precipitation. The outlook for March, April and
May show an equal chance of both temperatures and precipitation
being above or below normal.
...Spring Flood Risk...
The Spring flood risk is normal to below normal and highest in
Northeast Minnesota. Precipitation and rate of melt through early
spring while the ground is still frozen is one of the most important
flood risk factors. Frost depths of 30 inches or deeper are common
which is much deeper than normal. The presence of deep frost and its
affect on spring runoff are not explicitly accounted for in the
probability of flooding.
Thick river ice is present in many area waterways. If this ice
were lifted by strong river rises spring break up ice jams would
be possible. A significant rainfall event would be needed to cause
this scenario. Spring ice jam flooding is difficult to predict
and can quickly develop into a very hazardous situation.
In Table 1 below...the current (CS) and historical (HS) or normal
probabilities of exceeding minor...moderate...and major flood stages
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 more 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: 03/03/2025 - 06/01/2025
: 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
-------- ----- ----- ----- : --- --- --- --- --- ---
:Prairie River
Taconite 10.0 12.0 13.0 : <5 <5 <5 <5 <5 <5
:Mississippi River
Aitkin 13.0 15.0 18.0 : 12 52 5 31 <5 7
Fort Ripley 10.5 12.5 26.0 : 14 41 <5 19 <5 <5
:St. Croix River
Danbury 7.0 8.5 10.0 : <5 8 <5 <5 <5 <5
:Snake River
Pine City 9.0 10.0 11.0 : <5 8 <5 5 <5 <5
:St. Louis River
Scanlon 10.5 11.0 13.0 : <5 5 <5 <5 <5 <5
:Knife River
Near Two Harbors 33.0 34.0 36.0 : <5 <5 <5 <5 <5 <5
:Nemadji River
South of Superior 24.0 26.0 28.0 : <5 <5 <5 <5 <5 <5
:Tyler Forks
Mellen 9.0 10.0 12.0 : 25 35 14 25 <5 5
:Bad River
Near Odanah 16.0 18.0 20.0 : <5 <5 <5 <5 <5 <5
At Odanah 8.5 9.5 10.5 : <5 6 <5 <5 <5 <5
:South Kawishiwi River
Ely 6.5 7.5 8.5 : 8 25 <5 12 <5 <5
:Little Fork River
Little Fork 22.0 24.0 26.0 : <5 <5 <5 <5 <5 <5
:Vermilion River
Crane Lake 14.0 16.0 18.0 : 7 14 <5 <5 <5 <5
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--Exceedence Probabilities...
Chance of Exceeding Stages
at Specific Locations
Valid Period: 03/03/2025 - 06/01/2025
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Prairie River
Taconite 3.7 4.1 4.6 5.5 6.8 8.1 8.3
:Mississippi River
Aitkin 6.7 6.8 8.5 9.7 12.0 13.6 15.0
Fort Ripley 5.8 6.1 6.6 7.9 9.0 10.8 11.9
:St. Croix River
Danbury 1.9 2.3 2.7 3.2 4.5 5.2 6.1
:Snake River
Pine City 4.7 5.0 5.4 6.1 7.0 8.0 8.3
:St. Louis River
Scanlon 5.5 5.7 6.5 7.2 8.4 9.2 10.0
:Knife River
Near Two Harbors 27.9 28.0 28.5 28.8 29.2 30.0 30.9
:Nemadji River
South of Superior 10.4 11.8 13.3 15.0 19.0 22.1 22.9
:Tyler Forks
Mellen 6.1 6.5 7.3 7.8 9.0 10.5 11.4
:Bad River
Near Odanah 5.7 6.1 7.0 7.6 9.4 12.0 13.1
At Odanah 3.7 3.9 4.4 5.0 6.2 7.3 8.0
:South Kawishiwi River
Ely 4.4 4.6 5.0 5.3 5.8 6.5 6.6
:Little Fork River
Little Fork 5.7 6.5 6.8 8.3 10.3 12.5 15.0
:Vermilion River
Crane Lake 8.9 9.9 10.4 11.1 12.2 13.2 14.3
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--Nonexceedence Probabilities...
Chance of Falling Below Stages
at Specific Locations
Valid Period: 03/03/2025 - 06/01/2025
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Prairie River
Taconite 0.1 0.1 0.1 0.1 0.1 0.1 0.1
:Mississippi River
Aitkin 1.3 1.3 1.3 1.2 0.9 0.7 0.6
Fort Ripley 2.4 2.3 2.2 2.0 1.8 1.5 1.2
:St. Croix River
Danbury 0.9 0.9 0.9 0.8 0.8 0.8 0.8
:Snake River
Pine City 0.3 0.3 0.2 0.2 0.1 0.1 0.1
:St. Louis River
Scanlon 1.3 1.3 1.2 1.1 1.1 0.9 0.9
:Knife River
Near Two Harbors 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:Nemadji River
South of Superior 0.1 0.1 0.1 0.1 0.0 0.0 0.0
:Tyler Forks
Mellen 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:Bad River
Near Odanah 0.1 0.1 0.1 0.1 0.1 0.1 0.1
At Odanah 0.3 0.3 0.3 0.3 0.3 0.3 0.2
:South Kawishiwi River
Ely 0.1 0.1 0.1 0.1 0.1 0.1 0.1
:Little Fork River
Little Fork 0.1 0.1 0.1 0.1 0.1 0.1 0.1
:Vermilion River
Crane Lake 0.1 0.1 0.1 0.1 0.1 0.1 0.1
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/dlh for more weather and water
information.
For additional information on stream flow conditions for USGS
locations please reference https://dashboard.waterdata.usgs.gov
For additional information on stream flow conditions at MNDNR sites
www.dnr.state.mn.us/waters/csg/index.html
or
www.climate.umn.edu/dow/weekly_stream_flow/stream_flow_weekly.asp
For more information on climate outlooks reference
www.cpc.ncep.noaa.gov
The next outlook will be issued March 13th.
$$