Red River Valley spring flood risk remains in moderate to low major flood range
The Red River has a 90% chance of reaching 30.7 feet and a 5% risk of 39 feet in Fargo, where major flooding starts at 30 feet.
FARGO — The consistently cold but dry weather pattern the last two weeks means the spring flood outlook in the Red River Valley remains in the moderate to low major flooding range.
The spring flood risk is largely unchanged since two earlier outlooks released in February as the spring thaw approaches, according to an outlook issued Thursday, March 10, by the National Weather Service.
Stream flows along the Red River and its tributaries in North Dakota and Minnesota remain 25% to 75% of normal.
The snowpack, which runs from 90% to 140% of normal, holds between two inches and five inches of liquid.
The consistently colder-than-normal temperatures have enabled frost to penetrate from 20 inches to 60 inches. The frost depth in Fargo is 24 inches. It's 37 inches in Grand Forks.
The National Weather Service's latest outlook includes a range of possible flood levels along the Red River, with varying probabilities:
- At Fargo, the Red River has a 90% chance of reaching 30.7 feet, a 50% chance of 33.6 feet, a 10% chance of 37 feet and 5% risk of 39 feet. Major flooding starts at 30 feet; the record 2009 flood crested at 40.84 feet.
- Downstream at Grand Forks, the Red has a 90% chance of reaching 42.5 feet, a 50% chance of 45.2 feet, a 10% chance of 49.6 feet and a 5% chance of 52.4 feet. Jafor flooding in Grand Forks starts at 46 feet.
- Upstream at Wahpeton, near the headwaters, the Red has a 90% chance of reaching 12 feet, a 50% chance of 13.7 feet, a 10% chance of 16.5 feet and a 5% risk of 17.1 feet. Major flooding in Wahpeton starts at 15 feet.
The weather outlook for the next two weeks is volatile, with seesawing temperatures fluctuating above and below freezing, said Greg Gust, a weather service meteorologist.
If the thaw is gradual, much of a one-inch rainfall would soak into the soil. But if the melt is rapid, much of the rain would flow into the river, Gust said.
Soil moisture is running near normal, he said.
Fargo has a snow depth of about eight inches, although that is "highly compressed." The water contained within the snow cover generally ranges from three inches to five, up to six inches in some locations, he said.