Red's tributaries expected to produce overland flooding over next two days
Forecasters no longer expect the Red River in Wahpeton to crest a second time, but breakouts along tributaries should pick up over the next two days, a National Weather Service meteorologist said today.
The Red topped out just short of 16.5 feet in Wahpeton on Monday, but forecasters said Tuesday that peak flows from the Bois de Sioux River could cause a second crest late Thursday as high as 17 feet.
Greg Gust of the National Weather said this morning that ice jams on the Bois de Sioux weren't as heavy as expected, so the Red should drop slowly in Wahpeton.
North Dakota tributaries such as the Wild Rice and Sheyenne rivers could start to see more breakouts over the next two days as warm weather finishes off deeper snowpacks and breaks up river ice, Gust said.
At Fargo's flood briefing this morning, Mayor Dennis Walaker said the high water on the Red could cause small rivers like the Wild Rice to back up if they crested simultaneously.
Gust said forecasters still expect the peak flows from the Wild Rice to hit the Red a few miles south of Fargo early next week - Monday or Tuesday, a day or two after the Red's Fargo crest arrive Saturday or Sunday.
The staggered arrival of tributaries is keeping the Red lower but also extends the time it will stay high, Gust said.
"The fact that all of those are coming in with a little different timing is helping to take some heat off the height of the actual crest," he said.
If there are some minor breakouts, it could end up being favorable, Gust said. Overland flooding should freeze when colder weather hits this weekend, in effect sequestering that water as the main river channels keep flowing.
Predicting how ice will break up can be tricky, he said. That's why the crest forecast in Fargo, still forecast at 38 feet, has been pushed off a bit, possibly into Sunday.
"We knew that we were kind of shooting that crest in a little bit early," Gust said. "It was just because of the uncertainty on the ice."
Gust said the NWS is still working on the modeling on the Sheyenne. A second crest in late March or April is expected, but how large is not yet clear. Last year, an early crest was dwarfed by the record-setting levels the river hit in April, after the melt finished upstream.
"The Sheyenne still has to hold its breath a little bit," he said.