A series of powerful rainstorms is expected to hit the Bay Area beginning Wednesday morning, dumping up to 8 inches of rain on parts of the region, a National Weather Service forecaster said Monday.

The storms will start around the time of the morning commute on Wednesday and continue through the weekend, bringing winds of 40 to 50 mph and 1 to 3 inches of rain to most parts of the Bay Area, forecaster Steve Anderson said.

"This is certainly the biggest storm of the season so far," Anderson said. "Typically, we get our big rain events in December and January."

The rainfall will be most intense in the North Bay, where 2 to 3 inches of rain is expected in low lands and as many at 8 inches in the hills, Anderson said.

"It's mostly going to be a North Bay event, the heaviest rainfall," Anderson said.

Smaller creeks in the North Bay are likely to fill to bank level, although the larger Russian and Napa rivers "don't seem to be getting too out of hand," he said.

Streets throughout the Bay Area will be soaked, and fallen leaves from trees are expected to clog storm drains, so some roads and intersections will see some flooding and the usual traffic delays, Anderson said.

Bay Area residents should also get ready for possible downed trees and power outages.

"If you have an alarm clock that's electric, make sure you have a backup," Anderson said.

Fifteen- to 18-foot waves are expected along the coast during the stormy weather, he said.