Bay Area’s first wet cold front of the fall season arrives

By Carlos E. Castañeda

Wet weather signaled the arrival of the fall season in the Bay Area on Monday as the first wet cold front arrived with rain, gusty winds and possible thunderstorms. A second cold front was also expected by mid-week.

The National Weather Service said in its daily forecast discussion that the cold front was moving inland throughout the day on Monday, with the North Bay receiving the brunt of the rain. However, the totals were only expected to reach a quarter-inch by the evening. The Peninsula could see about a tenth of an inch of rain, while the East Bay, South Bay and Central Coast were likely to see only light showers, if any.

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There is a chance of the cold front bringing isolated thunderstorms, with a 15% chance of activity in the North Bay late Monday afternoon into the evening. Strong winds are also expected ahead of the system as widespread southerly flow continues across the region. 

Daytime highs on Monday are expected to range from the high 60s to low 70s on the coast, low 70s around the bay, and the mid to high 70s inland. Overnight lows will be mostly in the upper 50s to low 60s. 

Conditions should calm briefly on Tuesday, with drier weather and possibly some sunshine, although temperatures will remain on the cooler side, the Weather Service said. 

A second cold front that could be stronger and more widespread was expected on Wednesday, delivering up to a half-inch of rain in the North Bay and lighter amounts elsewhere around the Bay Area. Thunderstorm chances will be lower midweek, but forecasters said some instability will linger.

By Thursday, most of the wet weather should flow out of the region, but the Weather Service said the weekend outlook remains uncertain.