(USATODAY.com) - River flooding that's already swamping part of the Midwest could get worse Tuesday and Wednesday with more rain and snow spreading over the region.
Areas from Oklahoma through Michigan are forecast to get an inch of rain Tuesday, and some places twice that, by the time the storm moves away later Tuesday night, the National Weather Service forecasts. To the north, up to 9 inches of snow is possible in the Minneapolis/St. Paul area, according to the weather service.
As of late Monday, the heaviest snowfall was recorded in western South Dakota, where more than a foot of snow fell, according to the Weather Channel. The snow was yet another blow for the winter-weary northern Plains, which has seen record amounts of snow and record cold temperatures this month.
The good news is that this system should be less intense and faster-moving when compared to last week's torrential rainstorms that sparked the worst of the floods, according to AccuWeather meteorologist Alex Sosnowski. However, this additional rain could keep the rivers that are already at flood stage from receding as fast.
As of late Monday afternoon, more than 170 gauges were in flood stage across the USA, almost all of them in the upper Midwest, according to the weather service. This included 41 at "major" flood stage. Major flood stage means there will be "extensive inundation of structures and roads, and that significant evacuations are likely," according to the weather service.
Caused by the extremely heavy rain that fell last week, the surge of high water is slowly making its way down the Mississippi and Illinois rivers and their tributaries, according to Steve Buan, a hydrologist with the North Central River Forecast Center in Chanhassen, Minn.
He says that as of Monday afternoon, the Mississippi River is at or near its peak now from the Quad Cities of Iowa down to near Hannibal, Mo.
Spots to the south of St. Louis aren't expected to crest until later this week, and significant flooding is possible in places like Ste. Genevieve, Mo., Cape Girardeau, Mo., and Cairo, Ill.
In Grand Rapids, Mich., the worst appeared to be over Monday. The Grand River in the city's downtown crested Sunday night at 21.85 feet. It is expected to drop about a foot a day and fall below the 18-foot flood stage Thursday, city officials said.
"None of us have ever experienced anything quite like this," Grand Rapids Mayor George Heartwell said Monday.
The Red River of the North, which flows to the north into Lake Winnipeg in Canada, should reach peak levels by next week, according to Buan. The Red River forms the border between North Dakota and Minnesota, and faces a flood threat each year because of melting snow and spring rains.
In Fargo, the Red River is forecast to reach major flood stage of 30 feet by this weekend, according to a weather service website that predicts river flood levels. The current river level in Fargo is about 16.5 feet, slightly up from the 15-foot level its been at for the past week.
In an online report, the weather service in Grand Forks noted that by Friday and into the weekend, "temperatures are expected to rise significantly ... resulting in significant snowmelt runoff and more rapid rises in river levels."
So far, the Midwest flooding has caused three deaths and could be responsible for two more.