Published January 28 2011
Devils Lake outlook worsensThe latest spring flood outlook released Thursday by the National Weather Service brought more bad news for Devils Lake and minor changes for those living along the Red River and its tributaries.
There’s now a 50 percent chance the Red River at Fargo will exceed 37.3 feet, compared with a 50 percent chance of 37.4 feet in the Jan. 18 outlook.
Thursday’s outlook also gives the Red at Fargo a 20 percent chance of hitting 40.7 feet, which would be just shy of the record crest of 40.84 feet set in 2009.
Devils Lake is forecast to rise roughly half a foot higher than predicted in the last outlook issued for the lake on Dec. 23, the weather service said.
Thursday’s outlook gives the lake an 80 percent chance of rising to 1,454.5 feet – about 2.5 feet higher than the previous record of 1,452.05 feet set on June 27.
The lake’s natural spillover into Tolna Coulee is at 1,458 feet, and there remains about a 1 percent chance the lake will rise to within a foot of that mark.
Devils Lake Mayor Dick Johnson said city leaders plan to meet with the U.S. Army Corps of Engineers on Feb. 8 to talk about protection measures, The Associated Press reported.
Subtle changes in the outlook for the southern Red River basin were based on snowfall since Jan. 13 and efforts by the weather service and corps to better identify what happens when swollen rivers break out of their banks and flow into other rivers, said Mark Ewens, a meteorologist and data manager at the weather service in Grand Forks.
For instance, while Thursday’s outlook lowered Fargo’s 50 percent flood chance by one-tenth of a foot, it bumped up the 10 percent probability from 42 feet to 42.6 feet.
“It really hadn’t been an issue up until ’96-’97, and it’s become fairly common unfortunately in the last couple of big floods,” Ewens said of breakouts.
At more moderate flood levels, mitigation measures such as the Maple River Dam may reduce flood stages slightly, he said.
Fargo officials this week said the city will take temporary measures to raise flood defenses to 44 feet, allowing for 2 feet of freeboard at a river level of 42 feet. The decision was based on the 10 percent chance of a 42-foot crest.
Mayor Dennis Walaker said the city won’t alter its plans for now, despite the revised 10 percent chance of a 42.6-foot flood.
“Will my mind change? That will be based on what we get (for precipitation) in the next 30, 40 days,” Walaker said.
The revised outlook gives the Sheyenne River at Valley City a 50 percent chance of exceeding 16.8 feet, up from 16.7 feet in last week’s outlook, and a 10 percent chance of beating 20.8 feet, up from 20.7 feet last week. The Sheyenne crested at a record 20.65 feet in 2009.
In Lisbon, the 50 percent chance level on the Sheyenne fell from 19.5 to 19.1 feet, while the 10 percent chance level rose from 24.2 to 24.8 feet.
Flood factors line up
The National Weather Service cites three main factors behind this year’s ominous flood forecasts:
- Soils were wet or very wet heading into freeze-up.
- Parts of southeastern North Dakota, west-central Minnesota and the Devils Lake basin are way above average for snowfall.
Fargo’s 56.9 inches of snow so far this winter is 16.9 inches above its long-term average for an entire winter. By comparison, the city had received 75 inches of snow by Jan. 26, 1997.
- A La Nina weather pattern is expected to hold through spring, bringing the possibility of a cooler, stormier, wetter spring.
Readers can reach Forum reporter Mike Nowatzki at (701) 241-5528