Up to 2 inches of rain within 24 hours for Seattle area with arrival of another atmospheric river

An atmospheric river that could dump up to 2 inches of rain on Seattle — and as much as 3 inches on Shelton, Olympia and Tacoma — all within a 24-hour period is here.

Because the river of rain is expected to camp out over the Puget Sound region for at least a day, instead of moving in and out, the National Weather Service of Seattle is predicting heavier than usual rain through Friday afternoon.

If people “can clear the storm drains, that’s a good idea,” said Matthew Cullen of the weather service. “And for people who don’t have to travel or be out in it, staying home is a good idea.”

The weather service is predicting that numerous rivers in Western Washington will be above flood stage and that there could be some urban flooding as well, Cullen said.

There is a potential for 15 to 25 rivers in the region, including the Snoqualmie River, to be above flood stage by Friday afternoon, said meteorologist Dana Felton. The Skokomish River near Potlatch was a couple of tenths of a foot below flood stage around 6 p.m. Thursday.

A few thunderstorms moved inland along the coast late Thursday morning, though the National Weather Service said storms weakened as they moved inland.

Flood warnings were in place Thursday night for the Snoqualmie River near Snoqualmie Falls and the Tolt River above Carnation, as well as the Puyallup River near Orting, Nisqually River near National and the Skokomish River.

Conditions are expected to lighten up Friday afternoon with rain tapering off by 3 p.m. Though most of Saturday is expected to be dry, there is a chance of isolated showers in Seattle and elsewhere in Puget Sound.

The next round of showers is predicted to push in Saturday evening and bring at least another half-inch to 1 inch of rain to Seattle. If it stalls out overhead, Cullen said, we could stay wet through Sunday.

But it hardly matters when it stops. Another round of heavy rain is expected to follow, bringing more rain Sunday night into Monday.

How heavy Sunday’s rain showers will be is still in question, Felton said.