By David Bailey
MINNEAPOLIS (Reuters) - Flooding caused by ice jams forced closure of two central Minnesota highways on Monday, and looming early spring rain and snow storms have complicated river crest forecasts from North Dakota to western Wisconsin.
Along the Red River that forms the border between North Dakota and Minnesota, a storm is expected to bring up to 3/4-inch of rain to the lower section of the valley and up to a foot of snow to areas from Fargo north to the Canadian border.
Temperatures are expected to drop back below freezing by Wednesday, delaying the thaw at least a week and increasing the risk for a rapid melt combined with heavy rains, said Greg Gust, a National Weather Service meteorologist.
"We have a lot of water in a lot of snowpack that has to melt and flow through this river and the later we push it into the spring the worse generally the consequences," Gust said Monday in a phone interview from Grand Forks, North Dakota.
A wet fall and snowy winter has left the Upper Midwest saturated with forecasts for record or near record crests on major rivers including the Red River, Minnesota, Mississippi and St. Croix and several smaller tributaries.
That situation has cities from Fargo, North Dakota, on the Red River to Stillwater, Minnesota, on the St. Croix filling sandbags to hold back swelling rivers -- and waiting.
Since 1997 flooding, communities along the Red River have moved farms and homesteads from areas that sustain minor to moderate flooding, but "hundreds and hundreds" are still at risk from major floods expected this year, Gust said.
In Fargo, volunteers have filled more than 2.5 million sandbags since February 14 and the city has four to five additional clay dikes to hold back the Red River, which is expected to crest there in early April, Fargo Mayor Dennis Walaker said.
"We just need to be alert and do what we can when we can," Walaker said in an interview on Monday. "In 2009 we didn't have any advanced preparations, this year we began planning in December."
In Minnesota, Highways 19 and 93 were closed at Henderson west of Minneapolis due to ice backing up along the Rush River, state transportation officials said. One lane of Highway 169 also was closed for a temporary dike operation nearby.
The storms could bring up to an inch of rain to central and southern Minnesota by Wednesday, before temperatures cool and limit the amount of snow that melts, said Todd Krause, a Twin Cities meteorologist at the National Weather Service.
Krause said it probably would take longer for the Minnesota and Mississippi rivers to reach crests than previously expected and the waters will likely be at or above flood stage for a prolonged period, adding to stress on levees and dikes.
"If you wind up with high water all the way through mid or late April, some dikes and levees are in great shape, but there might be some that might not be," Krause said.
In North Dakota, the hoped-for continued gentle warming and light precipitation that would lead to the best case for thawing has not played out.
"The reality is we are expecting it to be active and we are expecting the storm that we have to deal with tomorrow and Wednesday is only one of what could be several more storms yet before this flood is over," Gust said.
(Additional reporting by Brianna Ehley in Fargo; Editing by Jerry Norton)