Rain To Arrive In Petaluma, Bring Chance Of Thunderstorms

PETALUMA, CA — Following sunny skies earlier Friday, rain was expected to start falling late Friday afternoon in Petaluma, with a 90 percent chance the rain would continue overnight and much of Saturday.

Forecasters with the National Weather Service for the greater San Francisco Bay Area said a cold frontal zone associated with a low-pressure system would sweep through the region from northwest to southeast on Friday with a band of showers accompanying it.

Rain chances were expected to increase first across the North Bay, then across San Francisco before reaching the Central Coast.

Breezy winds were expected to precede the frontal passage with low elevation gusts reaching up to 30 mph and gusts topping out around 45 mph.

According to the NWS, overall impacts from the wind and rain should be minor, except for some localized flooding on roadways or fallen trees. Scattered showers were likely to return overnight.

There was also a slight chance of isolated thunderstorms with lightning and brief heavy rainfall as the primary hazards. Overnight rain amounts should be light but heavier showers or thunderstorms were also possible.

Forecasters projected drier conditions would return by early next week, with rain chances returning mid to late week.

Petaluma 7-Day Forecast

Friday Afternoon
Rain. Steady temperature around 58. South wind around 15 mph, with gusts as high as 29 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Friday Night
Rain, mainly after 5am. Patchy fog after 5am. Low around 46. West wind 5 to 10 mph becoming light and variable after midnight. Winds could gust as high as 20 mph. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch possible.

Saturday
Rain before 8am, then showers and possibly a thunderstorm after 8am. Patchy fog before 8am. High near 58. Light and variable wind becoming west 9 to 14 mph in the morning. Winds could gust as high as 22 mph. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Saturday Night
Showers and possibly a thunderstorm before 11pm, then rain likely after 11pm. Patchy fog between 10pm and 11pm. Low around 45. West wind 3 to 8 mph. Winds could gust as high as 21 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Sunday
A 20 percent chance of rain before 11am. Mostly sunny, with a high near 62. Northwest wind 7 to 11 mph. New precipitation amounts of less than a tenth of an inch possible.

Sunday Night
Mostly clear, with a low around 43.

Monday
A 20 percent chance of rain after 11am. Partly sunny, with a high near 60.

Monday Night
Mostly cloudy, with a low around 42.

Tuesday
Mostly sunny, with a high near 64.

Tuesday Night
Mostly cloudy, with a low around 44.

Wednesday
A chance of rain. Mostly cloudy, with a high near 60.

Wednesday Night
Rain likely. Mostly cloudy, with a low around 44.

Thursday
A chance of rain. Partly sunny, with a high near 58.

Thursday Night
A chance of rain. Mostly cloudy, with a low around 44.

Friday
Rain likely. Mostly cloudy, with a high near 57.

Bay City News Service contributed to this report.