Bay Area drivers should exercise extra caution because the rain forecast for today, Monday, will be the first significant rainfall of the season, causing extra slippery roadways, the National Weather Service said.
Rain is forecast to spread through the Bay Area today, with the possibility of further off-and-on showers through Wednesday.
The weather service also warned of dangerous driving conditions in a "Hazardous Weather Outlook":
"MOTORISTS ARE URGED TO USE CAUTION AS THIS FIRST SIGNIFICANT RAIN OF SEASON FOR MUCH OF THE AREA WILL RESULT IN LEACHING OUT OF LONG-ACCUMULATED OILS IN THE PAVEMENT...AND THUS VERY SLIPPERY ROADWAYS."
Rainfall totals through tonight are forecast to be around 1-1/4 inches in the wettest portions of the North Bay coastal hills and to range between 1/4 and 1/2 inches at lower elevations around the Bay, the weather service said.
"We had quite a strong rain event this morning about 7:45 to 8 a.m.," said Half Moon Bay resident Dennis Paull, who recorded a peak rain rate of 9.25 inches an hour, with .52 inches in the 15 minute period. "And the peak wind speed was 35 mph. This showed up as a small but intense cell on the weather bureau radar, probably not more than a mile or two north to south in extant."