The snowfall itself was not expected to worsen the flooding, but engineers were worried waves could crash against the levees, further weakening them.
The higher the wind speed, the higher the threat, said Jeff DeZellar, a spokesman for the U.S. Army Corps of Engineers.
"The forecast that we saw was 25 mph or more, and certainly that's enough wind to create some wave action on the river," he said Monday.
National Guard members placed sheets of plastic over the levees to help them hold up against high waves. "It's important to get as much work done as we can before the storm comes," DeZellar said.
The snow is more of a concern in the southern part of the state, where some towns could receive up to 14 inches.
"We are looking at a full-blown blizzard," National Weather Service meteorologist John Paul Martin said. "It is a dangerous situation."
By midday Monday, the Red had fallen to just above 39 feet - down more than a foot from its nearly 41-foot crest on Saturday. City officials said they wouldn't breathe easy until it falls to 37 feet or lower, expected by Saturday.
"The difficulty with an epic flood is nobody has been through it before," said city commissioner Tim Mahoney. "You can't ask someone, 'Hey, what's going to happen next?'"
The week began with much of Fargo shut down, school called off for the entire week and many businesses keeping their doors closed because of the Red River, which was ebbing after its steady, threatening rise last week. With the storm expected to arrive from the west during the afternoon and last through Tuesday evening, many people just wanted things to get back to normal.
"I just think everyone is stir-crazy now," said resident Kathy Roscoe.
People were especially anxious as it gets tougher to pay the bills after a week of not drawing paychecks. "I'm not sure how I'm going to do it right now," said 24-year-old hair stylist Amber Fischer said of her paycheck-to-paycheck existence.
Fargo's mayor said to get ready for more breaches Monday - which is why helicopters are now fortifying the barricades with 1-ton sand bags and why volunteers are back at work after a two-day lull filling the smaller variety just in case, CBS News correspondent Dean Reynolds reports.
Helicopter crews sought to fortify the levees Sunday by dropping 11 one-ton sandbags near vulnerable areas of the dike system. Above them, an Air Force unmanned Predator drone flew to watch flood patterns and ice floes and provide in-depth information to teams on the ground. North Dakota has more than 2,400 National Guard troops engaged in the flood fight across the state.
Crews prevented more widespread damage in nearby areas. School officials also frantically raced to rescue a cockatiel, parakeet, tortoises, iguanas and snakes kept at the school as part of its science program.
Mayor Dennis Walaker called the incident at the school a "wakeup call" and a sign of the type of flooding that could happen at any time in the coming week.
"The main event is right now, while we have this higher water. And it ain't over till it's over," said U.S. Rep. Earl Pomeroy, D-N.D. "And it ain't gonna be over until several days from now."
While officials say they have limited the damage to a small number of homes within Fargo's city limits, several outlying rural areas have seen significant flooding. Cass County sheriff's deputies toured some of these areas Sunday in giant National Guard vehicles, offering assistance to stranded residents.
They encountered a woman whose prescription drugs were about to run out, people who trudged out of their homes in waders and a couple who gladly got a lift out of the neighborhood on the Guard truck. All the while, huge sheets of ice floated over people's yards and lawn furniture and children's toys could be seen stacked up behind sandbag lines.
It was a surreal scene that reminded deputies what kind of harsh terrain they are trying to overcome.
In one of the neighborhoods, Todd Cook sent his family to town and flew in his brother from Arizona to stay at the house and fight back the water. "It was nice to see the sheriff's department come out. It makes you feel better when you know you've got people caring. You hear everything about the city, but up here we're forgotten."
Then he broke down and walked back to the house through his flooded yard.
Fargo's water and sewer plants are right next to the river, and are protected by a secondary dike system.
"If we lose water and sewer, the city is uninhabitable," said Fargo City Administrator Pat Zavoral.
Moorhead, a city of 30,000 directly across the river in Minnesota, also was fighting to hold back the river. A husband and wife had to be rescued by boat from their home after they became trapped on the second floor.
Moorhead Mayor Mark Voxland said he was concerned but still optimistic about how long his city's dike could last against the pressure of the river water.
The flood was caused by an enormous winter snowfall that melted and combined with more precipitation to send the river to record levels. The river flows from south to north through the tabletop terrain of North Dakota, providing few opportunities to drain.
"The place is so flat," said John Gulliver, a professor of civil engineering at the University of Minnesota. "It is totally flat so there's really no place for the water to go because it can't leave that quickly. So it just keeps backing up like a bathtub with a slow drain."
But by the time the snow from the latest storm melts, officials believe the worst of the flooding threat will have passed, at least for eastern parts of the state. More problems for central North Dakota could come later in the week, Martin said.
As the temperature rises into the 40s, the newly fallen snow will melt more quickly, he said. In Bismarck, he expected almost an inch of water on top of mostly frozen ground and ice-clogged rivers and creeks.
"The melting will be rapid ... and so that's our concern, that rivers and streams that are receding across the area will start to come back up again," Martin said.
Flooding statewide was blamed for two deaths, in central and western North Dakota, in what health officials said were apparent heart attacks brought on by flood-prevention exertion.