The first big coastal storm of the fall season is expected to hit as early as Wednesday evening.

A major weather system that spun off Typhoon Songda in the western Pacific is expected to hit coastal areas with up to two inches of rain in the lowlands, Danny Mercer, a meteorologist with the Seattle branch of the National Weather Service, said Tuesday. But the severity of the storm, Mercer said, depends on how it tracks in the area Friday and Saturday.

“We’re expecting two or three systems coming into the area beginning Wednesday evening and into Thursday and should see wet and windy weather through the weekend,” Mercer said. “Winds could be in the 40 to 60 mile per hour range, with potential high seas swells upward of 30 to 35 feet. Low pressure, combined with high sea swells, could result in some coastal flooding.”

The stronger of the systems, according to a Weather Service news release late Tuesday afternoon, is supposed to affect the region on Saturday and Sunday as weather models show a very deep surface low tracking into the area that could potentially bring heavy rainfall with rises in area rivers, bringing a greater potential for flooding.