Flood Potential Outlook
Issued by NWS Aberdeen, SD
Issued by NWS Aberdeen, SD
818
FGUS73 KABR 131952
ESFABR
MNC011-155-SDC013-017-021-025-029-031-037-039-041-045-049-051-057-
059-065-069-075-085-089-091-107-109-115-117-119-129-272300-
Probabilistic Hydrologic Outlook
National Weather Service Aberdeen SD
152 PM CST Thu Feb 13 2025
...SPRING FLOOD AND WATER RESOURCE OUTLOOK...
This Spring Flood Outlook is for the rivers and streams in northeast
South Dakota, portions of central South Dakota, and portions of west
central Minnesota.
With a lack of significant liquid water in the snow cover that does
exist across the area, along with ongoing drought conditions, the
chances for minor, moderate, or major flooding across much of the
region are generally below normal. The flood threat through this
spring, both in location and severity, will largely be determined by
future rain or snowfall.
The outlook through February 22nd is for increased chances for below
normal temperatures and below normal precipitation. The outlook for
later in the month is for increased chances for above normal
temperatures and below normal precipitation. The 90 day outlook for
February through April indicates increased chances for below normal
temperatures and equal chances for below, near or above normal
precipitation.
...CURRENT SNOW CONDITIONS...
Current snow depth ranges from no snow pack from the area south of a
line from Onida to Warner and north of a line from Pierre to Miller
to Doland, to generally less than 2 inches along the North Dakota
border. One exception is an area of 4 to 8 inches across far
northeastern South Dakota and west central Minnesota. The liquid
water content in the snow pack is generally a trace to one inch.
...CURRENT SOIL CONDITIONS...
Soil moisture is below normal across the entire area. Frost depths
are generally in the 2 to 4 foot range. The entire region is in
Moderate to Severe drought conditions.
...CURRENT RIVER CONDITIONS...
All of the rivers in the area are iced over. River levels and flows
are generally running near to below normal. The threat for break-up
ice jams appears low at this time. Any potential ice jam flooding
will be determined by how fast the ice melts and how much additional
flow can get into the rivers to raise and break up the existing ice
cover before it melts.
...Probabalistic Outlooks...
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:
Valid Period: 02/17/2025 - 05/18/2025
: 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
-------- ----- ----- ----- : --- --- --- --- --- ---
:Elm River
Westport 14.0 16.0 19.0 : 8 28 6 22 <5 9
:James River
Columbia 13.0 16.0 18.0 : 36 57 30 45 23 29
Stratford 14.0 17.0 18.5 : 36 54 24 42 11 31
Ashton 13.0 14.0 16.0 : 25 52 24 45 21 43
Redfield 20.0 22.0 25.0 : 15 42 15 41 14 39
:Snake Creek
Ashton 11.5 13.0 16.0 : 18 50 17 49 16 41
:Turtle Creek
:Big Sioux River
Watertown 10NW 10.0 11.0 12.0 : 5 19 <5 <5 <5 <5
Watertown Conifer 9.0 10.0 12.0 : 13 54 6 34 <5 <5
Watertown Broadwy 10.5 11.0 13.5 : 7 35 6 33 <5 <5
Castlewood 9.0 11.0 16.0 : 13 38 6 28 <5 <5
:Grand River
Little Eagle 15.0 17.0 21.0 : <5 27 <5 18 <5 7
:Moreau River
White Horse 21.0 23.0 25.0 : <5 22 <5 17 <5 11
:Bad River
Fort Pierre 21.0 25.0 27.0 : 5 8 <5 5 <5 <5
:Little Minnesota
Peever 17.0 22.0 24.0 : 9 24 <5 <5 <5 <5
:Minnesota River
Big Stone Lake 970.0 971.5 973.5 : <5 6 <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--Exceedance Probabilities...
Chance of Exceeding Stages
at Specific Locations
Valid Period:
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Elm River
Westport 4.1 4.1 4.6 5.4 7.6 13.0 17.4
:James River
Columbia 5.2 5.2 6.2 8.6 17.1 18.5 19.8
Stratford 6.3 6.3 7.4 8.9 16.6 18.7 20.2
Ashton 3.9 3.9 4.4 5.5 13.0 22.1 28.9
Redfield 3.8 3.8 4.3 6.2 15.0 30.4 33.7
:Snake Creek
Ashton 1.8 1.8 1.9 3.1 7.6 18.6 21.1
:Turtle Creek
:Big Sioux River
Watertown 10NW 4.4 4.5 4.6 5.1 6.6 9.2 10.2
Watertown Conifer 5.3 5.3 5.7 6.2 6.9 9.3 10.5
Watertown Broadwy 5.1 5.1 5.3 5.6 6.4 9.5 12.0
Castlewood 5.1 5.1 5.3 5.5 6.5 10.6 11.7
:Grand River
Little Eagle 3.8 4.7 5.4 6.9 9.8 11.6 13.2
:Moreau River
White Horse 4.5 4.9 5.8 6.5 8.6 12.1 14.8
:Bad River
Fort Pierre 1.8 2.7 4.4 5.7 9.7 13.8 22.1
:Little Minnesota
Peever 11.6 11.8 12.4 13.4 14.5 16.7 18.4
:Minnesota River
Big Stone Lake 966.3 966.4 966.5 966.5 966.5 967.4 968.4
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:
LOCATION 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Elm River
Westport 4.1 4.1 4.0 4.0 4.0 4.0 4.0
:James River
Columbia 5.2 5.2 5.2 5.1 5.1 5.0 5.0
Stratford 6.2 6.2 6.2 6.2 6.2 6.2 6.2
Ashton 3.8 3.8 3.8 3.8 3.8 3.7 3.7
Redfield 3.6 3.6 3.6 3.6 3.6 3.6 3.6
:Snake Creek
Ashton 1.8 1.8 1.8 1.8 1.8 1.8 1.8
:Turtle Creek
:Big Sioux River
Watertown 10NW 4.1 4.1 4.1 4.1 4.1 4.1 4.1
Watertown Conifer 5.0 5.0 5.0 5.0 5.0 5.0 5.0
Watertown Broadwy 4.9 4.9 4.9 4.9 4.8 4.8 4.8
Castlewood 4.5 4.5 4.5 4.5 4.4 4.4 4.4
:Grand River
Little Eagle 2.6 2.6 2.6 2.6 2.6 2.5 2.5
:Moreau River
White Horse 2.1 2.1 2.1 2.1 2.1 2.1 2.1
:Bad River
Fort Pierre 0.5 0.5 0.5 0.5 0.5 0.5 0.5
:Little Minnesota
Peever 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:Minnesota River
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/abr for more weather and water
information.
The next outlook will be issued on February 27th, 2025.
$$
Parkin