COEUR d'ALENE - National Weather Service in Spokane has issued a flood warning for urban areas and small streams in Kootenai County, which includes the cities of Rathdrum, Post Falls, Hayden, Dalton Gardens and Coeur d'Alene.

The flood warning is in effect until 1 p.m. Sunday, said Doug Fredericks, director of the Kootenai County Office of Emergency Management.

"We are not too concerned about the main rivers or lakes flooding," he said, adding the concern is for low-lying areas that are prone to gather water.

Fredericks said recent colder-than-normal temperatures have left the ground frozen solid, with little capacity to absorb any melting snow or newly fallen precipitation.

"We actually saw some pretty weird stuff up near Clagstone Road in the Athol area," Fredericks said. "Water was pooled up and they had never seen anything like this before."

The frozen conditions will be compounded by the forecasted arrival of three warm weather patterns during the week, accompanied by a mix of rain and snowfall, according to Ellie Kelch, a meteorologist with the National Weather Service.

"We have a very strong deep stream of moist air coming off the Pacific," Kelch said. "That'll bring in a line of storms one after another. We'll have one almost every other day for the next five days."

The condition is known as an "atmospheric river" because on satellite imagery it looks like a river.

Kelch said the storms won't be all that bad, but the one they expect Saturday evening through Sunday morning may bring 12 hours of steady rain with a strong southerly flow.

"With the frozen ground, anything we get is going to flow straight into the rivers," she said.

In addition to the frozen ground, storm sewers, culverts and drainage ditches that are frozen and plugged with ice and snow may overflow.

"People need to clear their drainage grates," Kelch said. "That's what I am going to do when I get home from work tonight."

Pooling on roads may occur. If roads become flooded, do not drive or walk through flowing water, Fredericks warns. As little as 1 foot of water on the road can move most vehicles off the road.

Residents in low-lying areas prone to flooding should consider precautionary actions now, such as purchasing sand and sandbags. Sand and sandbags can be purchased from most local building supply stores and concrete companies.

"We just want people to be prepared," Fredericks said. "It's just kind of an early warning."

The Kootenai County Office of Emergency Management has sandbagging instructions and flood preparation information on its website: oem.kcgov.us.

Residents living in flood-prone areas should monitor local media for updated weather forecasts to get the latest on changing conditions and flood warnings, he said.