SEATTLE (AP) — Snow, sleet and freezing rain is making holiday travel challenging in Washington state, Oregon and Idaho.

The National Weather Service warned Portland Sunday afternoon that drivers should expect deteriorating road conditions through the day.

Weather forecasters said snow was falling west of Olympia and was beginning to accumulate in Chehalis, Washington.

They say 1 to 3 inches of snow could arrive by Christmas morning.

The weather service issued a winter storm warning from 7 p.m. Sunday until 4 p.m. in Idaho. The warning covers Palouse, Lewiston, lower Asotin and Garfield counties.