Midwinter outlook predicts minor to moderate spring flood risk along Red River
Fall rains and snowfall as of midwinter have eased the drought and produced conditions expected to result in minor to moderate flooding in the Red River Valley.
FARGO — The Red River Basin could see low to moderate flooding as the snow melts this spring, according to the National Weather Service's midwinter outlook, but precipitation through April will determine the magnitude.
Midwinter conditions create a moderate to somewhat high potential for significant snowmelt flooding, according to the flood outlook released Thursday, Jan. 27.
Lingering drought conditions, which were eased by fall rains, mean the soil has room to store moisture from snowmelt — provided the thaw is gentle.
“Climate outlooks currently indicate an increased risk for near-normal temperatures and precipitation through the late winter and early spring periods, which helps to keep our overall risk in check,” the outlook released by meteorologist Greg Gust said.
“The risk for significant snowmelt flooding is moderately high, running near to slightly above long-term historical averages across the Red River and Devils Lake basins,” the outlook said.
The outlook said the Red River at Fargo has a 95% chance of reaching 21.9 feet, a 75% chance of 27 feet, a 50% chance of 30.7 feet and a 5% chance of 39 feet. Major flood stage in Fargo begins at 30 feet. Minor flooding starts at 18 feet, with moderate flooding at 25 feet. The crest in the record 2009 flood was 40.84 feet.
In Grand Forks, the outlook predicted the Red River as a 95% chance of reaching 31.2 feet, a 75% chance of 39.3 feet, a 50% chance of 42.9 feet and a 5% chance of 50.3 feet. Upstream at Wahpeton, the Red River has a 95% chance of reaching 11.2 feet, a 75% chance of 11.9 feet, a 50% chance of 12.6 feet and a 5% chance of 16.4 feet.
Base stream flows are running near normal for this time of year, the NWS said. Analyses by the U.S. Geological Survey indicate the Red and most of its tributaries in North Dakota and Minnesota are moderately ice-covered and flowing at 25% to 75% of normal range.
As of Thursday afternoon, the Red River in Fargo was running at 14.34 feet and has been stable.
Conditions generally are a bit wetter in the far southern Red River Valley and a bit drier to the north, according to the outlook
Stream flows were running somewhat higher in the far southern basin and somewhat lower near the border with Canada. Similarly, soil moisture at freeze-up was near normal, though slightly above normal in the far southern basin and slightly below in the north.
The winter snowpack is “fairly well distributed across the area” but patchy because of drifting caused by storms and blizzards, according to the NWS. Since Dec. 1, snowfall has run 90% to 130% of normal.
The water equivalent in the snow ranges from 1½ to 3½ inches. The North Dakota tributaries have a slightly higher runoff potential across the southeast, decreasing toward the north and northeast.
Along the Sheyenne River, the soils hold near normal moisture. The mid and upper basin has somewhat above normal snowpack, and the lower Sheyenne Basin has near normal to above normal snowpack.
An updated spring flood outlook will be issued by Feb. 10.