Snowstorm Is the Last Thing the Flood-Weary Plains Needs

Jonathan Erdman
Published: October 10, 2019
Actual and forecast snow from the October Plains snowstorm – heaviest in the darker purple contours – and river gauges reporting levels above flood stage in the Missouri, Mississippi and Red River basins as of Oct. 10, 2019.

A snowstorm will leave its mark in the northern Plains well after it's gone.

Some parts of the Dakotas may see their all-time October snowstorm of record, which will likely trigger power outages, down trees, damage crops still left to harvest and impact livestock.

(DETAILED FORECAST: Plains Snowstorm May Set October Records

That's impactful enough.

But what about the leftover snowpack?

A Fast Snowmelt

If this storm happened in November or December, the snowpack would stick around, since average high temperatures in most of the Dakotas would be closer to freezing.

But it's mid-October and daytime highs average in the 50s or lower 60s with lows near or just above freezing.


Average October Highs

The snowpack from this winter storm will chill the air above it for several days after the storm is over.

But daytime highs are expected to rise above freezing, from the mid-30s into the 40s. Areas with less snowpack should eventually see highs in the 40s or 50s.

Because all this snow is so early in the season, it's expected to melt, and may do so completely as soon as next weekend.

And because the ground isn't frozen yet, this water from melted snow should seep into the soil, right?

Unfortunately, that's not the case.

Soil moisture is well above average for this time of year, in the top 1% of all values for the second week of October in the northern Plains, according to NOAA's Climate Prediction Center,

This ground was saturated by the wettest September in 125 years in North Dakota and among the top three wettest Septembers in South Dakota, Montana and Minnesota.

(IN DEPTH: A Record September to Remember

Area precipitation rankings for September 2019, compared to each September since records began in 1895. Areas in darkest green were record-wet in September.
(NOAA/NCEI)

More Water for Swollen Rivers

So that snowmelt has nowhere to go but into creeks, streams and rivers.

But some mainstem rivers are still running high.

The Red River in Grand Forks County, North Dakota, was closed for public use Wednesday due to rising water and colder water temperatures, the Grand Forks Herald reported.

The NWS expects the river to crest in Grand Forks about 12 feet above flood stage Oct. 15 or 16, above the level at which flood gates would need to be closed and water pumping stations activated in the city.

While nowhere near the city's all-time record flood from spring 1997, this would be the highest crest on record in the fall, according to NWS records.

"Overall, this is about as high of a flow as we see this time of year," Daryl Ritchison, director of the North Dakota Agricultural Weather Network, told weather.com

Stretches of the Missouri River have been above flood stage for months after flooding in March damaged levees and inundated millions of acres of farmland.

In early October, the U.S. Army Corps of Engineers announced releases from Gavins Point Dam, the southernmost dam along the Missouri River near Yankton, South Dakota, would remain at roughly twice the normal rate through November, the Sioux City Journal reported.

This photo from Aug. 6, 2011, shows water released below the Gavins Point Dam along the Missouri River near Yankton, South Dakota.
(U.S. Army Corps of Engineers)

This was due to prolific September precipitation in the river basin from Montana to northern Nebraska, which required higher releases at five dams upstream from Gavins Point.

The U.S. Army Corps is attempting to drain reservoirs upstream quickly to create capacity to handle runoff from spring snowmelt in 2020.

Snowmelt from this October snowstorm will only add to this seven-month Missouri flood saga.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.


The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.