UPDATE: A flood advisory for rapid rises due to rain and snow melt has been issued for all of southeast Nebraska and southwest Iowa until 7:45 p.m. this evening.
At 1:41 p.m., emergency management and storm spotters reported that snowmelt was causing minor flooding of both rural and urban roads. According to the National Weather Service, this situation will likely become more widespread Tuesday night into Wednesday as rainfall increases in areal coverage and intensity.
Some locations that will experience flooding include: Omaha, Lincoln, Norfolk, Columbus, Beatrice, Falls City, Council Bluffs, Bellevue, Fremont, Papillion, La Vista, Blair, Nebraska City, Seward, Crete, Plattsmouth, Schuyler, Ralston, Red Oak and Wayne.
If traveling, be alert to road closures and the potential for water-covered sections of road, the weather service said. This is especially the case at night when visibility is reduced.
A dense fog advisory is also in effect until 10 a.m. Wednesday for the same region. Visibility will be cut to less than a half mile.
Concern over flooding is growing as light right began to fall in Nebraska City and Falls City Tuesday morning.
On Monday, a National Weather Service hydrologist warned that major flooding is possible from eastern Nebraska into Iowa.
“This is not your typical flooding,” said David Pearson, the hydrologist. “This could be a significant situation.”
Pearson said a risk of flooding exists for those normally protected by levees. (Riverside residents unprotected by levees have been warned for days to move valuables out of harm’s way.)
“If this rain ends up on the higher end … and the right conditions occur with ice movement, it’s not out of the question for somebody to hit record or major flood status,” Pearson said.
The National Weather Service in Omaha issued a flood warning until further notice for the Missouri River affecting Mills, Cass, Fremont, Otoe, Atchison, Nemaha, Holt and Richardson Counties in southeast Nebraska, southwest Iowa and northwest Missouri.
Moderate flooding of the river is forecast. It’s expected to rise above flood stage by late Wednesday evening and continue to rise to near 25.6 feet by Sunday morning. Highway 2 may begin to flood at 25.5 feet.
Weather officials say not to not drive cars through areas where water covers the road. The water depth may be too great to allow your vehicle to pass safely. “Turn around…don`t drown!”
In the Omaha area, 1.5 to 2.5 inches of rain is possible, but farther west toward Columbus, 2 to 3 inches could fall, Pearson said. Those rainfall amounts aren’t extraordinary, but what makes this situation dangerous is the frozen ground, already high streams and still widespread snowpack.
Pearson said a “very reasonable” step would be to elevate or move some possessions. “I would,” he said. “It’s an effort you can do that’s tangible.”
Pearson’s concerns were echoed by Bob Heimann, operations and maintenance manager for the Lower Platte North Natural Resources District.
“Starting on Wednesday, people on the safe side of the levees better keep their eyes open,” he said. “Essentially, it’s everybody, whether you live in a community, on an acreage or a farmstead. You need to keep your eyes open. We don’t know where it might happen, if it does happen.”
Of special concern is any ice jam that might happen overnight, when it’s difficult to see what’s happening.
Pearson and Heimann said people need to take responsibility for their own well-being and not count on getting notification.
“Stay aware of conditions,” Pearson said. “Don’t just hope somebody will let you know.”
That said, the U.S. Geological Survey monitors stream levels and provides alerts to those who sign up. The weather service will issue warnings when it becomes aware that something has occurred.
Earl Imler, operations manager for the Nebraska Emergency Management Agency, said state and federal authorities have been working with local officials to prepare. Sandbags and extra sand have been pre-positioned in areas requested by local emergency managers, he said.
“At this point, it’s just wait and see,” Imler said. “We’ve done all the preparation and planning we can do.”
All of eastern Nebraska and significant portions of Kansas, Iowa and Minnesota are under a flood watch because of the huge size of the storm.
Pearson said there’s time to prepare. The heaviest rain doesn’t come until late Tuesday into Wednesday.