Frost, Rain, Snow May Dampen Northern California At Start Of Halloween Week

SAN FRANCISCO (CBS SF) -- Bay Area residents might have to bundle up this week as a cold-weather front brings a change to colder temperatures, a National Weather Service forecaster said.

A fast-moving low pressure system is developing over the Pacific Northwest and is heading south, forecaster Logan Johnson said Sunday.

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The front brings the possibility of the season's first frost in North Bay valleys, where temperatures could drop into low to mid 30s Tuesday through Thursday nights, Johnson said.

Low temperatures in the San Francisco area are expected to be in the upper 40s, with highs in the upper 50s, according to the Weather Service.

There is a slight chance of rain across the Bay Area after midnight Sunday, Johnson said.

"Unfortunately for us, there is not a lot a moisture associated with the system," he said.

High elevations in the South Bay have the highest chance of rain, he said.

The Weather Service issued a wind advisory for Sunday night, when gusts could reach 45 mph in higher elevations.

Northwest winds between 15 mph and 25 mph are expected throughout the region Sunday evening and should die down before sunrise on Monday, according to the Weather Service.

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