HAPPY CAMP, Calif.—Weather officials are issuing flood warnings for much of Northern California as the second in a series of wet storms hits the state.

The National Weather Service on Thursday issued a variety of warnings for heavy rain, snow, high winds and floods from the San Francisco Bay area to the Oregon border.

Officials say intense rainfall is expected overnight through Friday morning before another storm hits Sunday.

The service says small rivers and streams are at increased risk for flooding, especially in the upper Sacramento River region.

Officials say the storm could cause flooding on roads and trigger rock and mud slides. Gusty winds could knock down trees and electricity lines, leading to power outages.

On the coast there are gale warnings and small-craft and high-surf advisories.