River watchers aren't relaxing anytime soon. A storm predicted this weekend could alter the flood forecast, depending on whether it delivers rain or snow.
The Mississippi River crested at St. Paul Wednesday and headed back down without substantial problems.
But the possibility of rain or snow through the weekend could complicate the region's flooding picture.
A storm expected to cross Minnesota Sunday and Monday could bring up to an inch of precipitation. But forecasters were not ready Wednesday to predict whether it would be in the form of rain, which would run quickly into already-high rivers quickly, or snow, which would hold the moisture back.
"We're hedging," said Diane Cooper, service hydrologist for the Twin Cities office of the National Weather Service (NWS). "The temperatures are really borderline. A degree or two makes all the difference in how much water that snowpack [remaining on the ground] is going to start releasing."
The NWS indicated Wednesday that the South Fork of the Crow River at Delano, which crested Monday at about its fourth-highest level ever, could rise that high again Tuesday. But Cooper described that as a "very nonconfident forecast," and subject to change depending on the coming precipitation. Other rivers are not expected to be as dramatically affected, she added, because their watersheds are larger than the Crow's.
There was some good flooding news Friday as Hwy. 99 was reopened where it crosses the Minnesota River into St. Peter. The Broadway Avenue bridge was closed Saturday.
The Minnesota River has been dropping this week after peaking at most cities along its length. It meets the Mississippi upstream from downtown St. Paul.
The Raspberry Island boathouse in downtown St. Paul remained above water Wednesday with the river merely lapping at the portals to the first level. The river levels didn't come close to requiring the evacuation of residents and businesses in the nearby Upper Landing area.
The river is expected to drop more than 3 feet by Tuesday. But forecasters continue to warn that all the region's rivers could see repeated crests this spring as the snow melts and spring rains arrive.
At St. Paul, the Mississippi has an almost 60 percent chance of seeing another crest even higher than Wednesday's, according to the North Central River Forecast Center.
Meanwhile, the Red River at Fargo-Moorhead, where much of the landscape is still covered with heavy snow, has begun a steady rise but Wednesday was running about 6 feet below the level that would prompt construction of a high, temporary clay dike downtown, one of the key symbols of major flooding in the city. Both Fargo and Moorhead will begin delivering sandbags to individual property owners in the next few days.
Bill McAuliffe • 612-673-7646