With Minnesota’s snowbanks piling ever higher, state weather officials warn that if the right thawing conditions occur, there’s a not-so-slim chance of record-breaking flood levels in some river cities next month.

As things sit now, every Minnesota city along the Mississippi River south of and including St. Paul has a better than even chance of major flooding next month, according to the National Weather Service.

At the Robert Street bridge in St. Paul, for example, waters reach “major flood stage” at 17 feet. There’s a 100 percent chance of that, the National Weather Service says — and better-than-even chances that the waters will rise 3 feet above it.

Things are a little better along the St. Croix: Stillwater has a 90.5 percent chance of hitting its major flood stage.

The weather service’s model takes into account forecasts over the next two weeks, including this weekend’s likely snowstorm.

And it’s not just because snowpack in spots here and upstate are among the top 10 on record. It’s because so many of them are.

“In a lot of years we’ll have a pretty big snowpack over one of the river basins,” said Craig Schmidt, senior service hydrologist with the National Weather Service in Chanhassen. There are three major river basins in the state: on the Mississippi, the Minnesota and the St. Croix.

And this year, “we’re seeing widespread, deep snowpack over all the basins. Not just one,” Schmidt said.

Thus, “There’s certainly potential that if they all melt at the same time, we’ll have a good flood wave down the Mississippi. … All of it will depend on a big warm-up.”

Stillwater citizenry is mobilizing. About 800 people have already volunteered for sandbagging work, according to the Stillwater Flood Volunteers page on Facebook.

In St. Paul, the chance of waters breaking the record crest of 26.01 feet, set in 1965, sits at 15 percent.

But here’s the good news: For that record level to happen, the state would have to experience a sudden warm-up, and current predictions don’t show that.

Still, the weather service is confident of its forecast only through March 22. Beyond that, things could get slushy — and historically, the river hits its peak in early to mid-April.

In St. Paul, aside from shutting down the commuter arteries of Shepard Road and Water Street on the West Side and streets around the Upper Landing just southwest of downtown, no major infrastructure should be affected, said Rick Schute, the city’s emergency management director.

“There’s a railroad bridge that the operator gets washed out further down,” Schute said. And Metro Transit officials noted some Union Depot service roads used by its buses would have to be rerouted in the case of a major thaw.

But while St. Paul’s flooding tends to hit areas that aren’t crucial, cities along the St. Croix River are a lot more vulnerable.

PREPARATIONS ALONG THE ST. CROIX

Closing parking lots to make room for sandbag filling. Issuing warnings to buy flood insurance. Praying for extended cool temperatures and a slow runoff. That’s what officials in the St. Croix River were doing Thursday in response to the almost-certain chance that the river will experience major flooding this spring.

Public works officials in Stillwater announced Thursday that parking lots east of Water Street in downtown Stillwater will be closed starting March 18 until further notice.

The projected level, 689 feet, is about even with the parking lots, said Public Works Director Shawn Sanders.

“If we don’t do anything, and it comes in higher, we’re going to be in a bad situation,” Sanders said. “It just depends on how the weather unfolds. If it’s cold and if it gets above 30 and freezes at night, the runoff is going to be less than if it’s 50 degrees every day and not getting below freezing at night.”

City crews plan to use the city-owned parking lot near River Market Co-op for sandbag building if they need to, Sanders said.

Afton Mayor Bill Palmquist on Thursday said residents should consider getting flood insurance soon because of a 30-day waiting period before it would go into effect.

“Some of the charts that they are showing, I’ve never seen them as high,” he said. “There’s a 90 percent chance we’re going to be at 689 or higher. I’ve never seen a chart like that.”

The city completed in 2018 four new major infrastructure projects — a community sewer system, an improved flood levee, a new stormwater system and reconstruction of St. Croix Trail and side roads — after years of planning and construction.

“We couldn’t be in a better place right now,” Palmquist said. “But we’re always working on contingencies. If it goes over 695, God forbid, we have plans that we are working on.”

About 8,670 homeowners in Minnesota have bought flood insurance from the National Flood Insurance Program, part of the Federal Emergency Management Agency, said James Sink, the flood insurance liaison for Minnesota and five other states.

The average annual flood insurance premium in Minnesota is $894 a year; the average amount of coverage per policy in the state is $256,319, Sink said. The average paid claim last year in the state was $7,715, he said.

At the federal level, for the last couple of days mayors from 20 cities along the Mississippi River corridor — including three from Minnesota — were in Washington asking for more infrastructure to shield them from potential disaster.

As part of the Mississippi River Cities & Towns Initiative, the mayors of Minneapolis, Red Wing and Bemidji pushed for the $7.8 billion plan that would focus on environmental infrastructure — such as flood mitigation — in river cities, via loans or grants through existing federal programs.