JANUARY FLOOD OUTLOOK

…RED RIVER BASIN OUTLOOK FOR RIVER FLOOD POTENTIAL… FROM THE NATIONAL WEATHER SERVICE
This outlook covers the Red River of the North
and its Minnesota and North Dakota tributaries.
…HIGH RISK OF MAJOR FLOODING THIS SPRING ALONG THE MAINSTEM RED
RIVER WITH WIDESPREAD MINOR TO MODERATE FLOODING ALONG THE
TRIBUTARIES…
This outlook covers the period from January 27, 2020 to May 19,
2020. Note that this period has been extended to encompass the
entirety of the spring flood season.
.OUTLOOK SUMMARY…
* Probabilities for exceeding Major, Moderate, Minor Flood Stage…
Major Flooding…
There is a high risk (greater than 65 percent) of major flooding
at Fargo/Moorhead, Halstad, Grand Forks/East Grand Forks, Oslo,
Drayton, and Pembina on the Red River. In North Dakota, there is a
high risk of major flooding at Valley City, Kindred, the West Fargo
Diversion, and Harwood on the Sheyenne River and at Abercrombie on
the Wild Rice River. In Minnesota, there is not a high risk of major
flooding at any forecast points with this outlook issuance.
There is a medium risk (35 to 65 percent) of major flooding at
Wahpeton/Breckenridge on the Red River. In North Dakota, there is a
medium risk of major flooding at Lisbon on the Sheyenne River,
Mapleton on the Maple River, and Neche on the Pembina River. In
Minnesota, there is a medium risk of major flooding at Hendrum on the
Wild Rice River, Climax on the Sand Hill River, and at High Landing
and Crookston on the Red Lake River.
There is a low risk (less than 35 percent) of major flooding
throughout the remainder of the basin with this outlook issuance.
Moderate Flooding…
There is a high risk (greater than 65 percent) of moderate
flooding at Wahpeton/Breckenridge on the Red River. In North Dakota,
there is a high risk of moderate flooding at Lisbon on the Sheyenne
River, Enderlin and Mapleton on the Maple River, Hillsboro on the
Goose River, and Neche on the Pembina River. In Minnesota, there is a
high risk of moderate flooding at Sabin on the South Branch of the
Buffalo River, Hawley and Dilworth on the Buffalo River, Hendrum on
the Wild Rice River, Climax on the Sand Hill River, Crookston on the
Red Lake River, Alvarado on the Snake River, and Hallock on the Two
Rivers River.
There is a medium risk (35 to 65 percent) of moderate flooding at
Hickson on the Red River. In Minnesota, there is a medium risk of
moderate flooding at Twin Valley on the Wild Rice River, Shelly on
the Marsh River, and High Landing on the Red Lake River.
Minor Flooding…
There is a high risk (greater than 65 percent) of minor flooding
at Minto on the Forest River and Walhalla on the Pembina River. There
is a medium risk (35 to 65 percent) of minor flooding at Roseau on
the Roseau River and Grafton* on the Park River. There is a low risk
of minor flooding near Warren on the Snake River.
*Note: With the recent completion of the Grafton Bypass, river
flows will be divided between the main channel and the diversion.
This will significantly reduce the impact on the City of Grafton and
surrounding areas protected by the diversion, and the in town river
gage at Grafton is not likely to reach the stages depicted here.
However, locations outside the protection of the diversion still have
the depicted risk probability associated with historic levels on the
Grafton gage.
.OUTLOOK DISCUSSION…
Hydrologic and climate conditions which affect each of the several
factors that significantly determine the timing and magnitude of
spring snowmelt flooding within the Red River of the North are
discussed below:
* SNOWPACK CONDITIONS…
The current snowpack and associated water content is above normal.
Since December 1, 2019, snowfall has been much above average (roughly
150 to 300 percent of normal). This has been the case for much of the
basin with the exception of far northeastern ND and northwestern MN.
The current water content of the snow ranges from 2.5 to 5.0 inches
which are values usually seen closer to snowmelt (i.e., running high
for this point in the winter).
* SOIL MOISTURE…
At the time of freeze-up, soil moisture was well above normal
across much of the basin due to record precipitation during the fall.
Some locations even had standing water frozen into some ditches.
* FROST DEPTHS…
Current frost depth values are shallower than normal due to early
and persistent snowcover this winter. The far southern valley
currently reports frost depth values of 6 to 12 inches while most
locations north of Fargo range from 14 to 30 inches.
* RIVER FLOWS…
Base streamflows are much above normal, even nearing record levels
for this time of year due to the record wet fall. The Red River and
most tributaries (mainly south of Oslo) are currently flowing at the
95th percentile or greater. Further north, flows are in the 76th to
95th percentiles.
* RIVER ICE…
River ice and lake ice thicknesses are currently less than normal
and quite variable across the region.
* FACTORS YET TO BE DETERMINED…
– Further snowpack growth,
– Rate of snowmelt/thaw,
– Heavy rain on snow or frozen ground during thaw or peak flood,
– Heavy rain on ice-covered rivers causing short-term ice jams.

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