The National Weather Service forecast for the greater San Francisco Bay Area for today calls for up to an 80 percent chance of precipitation before sunset, and up to 100 percent chance of heavy rain at night.
Daytime highs in the region will be mostly in the mid to high 50s. Overnight lows will dip into the high mid 40s to low 50s.
Forecasters say a new storm system moving through the Bay Area overnight is expected to dump heavy rainfall through Friday morning.
From today through Saturday, a Flood Watch will be in effect in San Francisco, Marin, Sonoma, San Mateo, Monterey and Santa Cruz counties.
A High Wind Watch has also been raised in the Bay Area and Central Coast from this evening until Friday morning. Expected powerful winds could down trees, snap power lines, move loose debris, and result in property damage and trigger power outages.
