Rain To Arrive In Napa Valley, Bring Chance Of Thunderstorms

NAPA VALLEY, CA — Following sunny skies earlier Friday in Napa Valley, the rain was expected to start falling by 5 p.m. with a 90 percent chance rainy conditions would continue in Napa Valley 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.

Napa Valley 7-Day Forecast

Friday Afternoon
Rain before 5pm, then showers and possibly a thunderstorm after 5pm. Steady temperature around 54. South wind around 17 mph, with gusts as high as 28 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Friday Night
Showers and possibly a thunderstorm before 8pm, then rain, mainly between 8pm and 11pm. Low around 44. South wind 7 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

Saturday
Rain before 11am, then showers and possibly a thunderstorm after 11am. High near 52. South wind 8 to 13 mph becoming west southwest in the afternoon. Winds could gust as high as 18 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 likely and possibly a thunderstorm before 11pm, then a chance of rain after 11pm. Patchy fog after 5am. Otherwise, mostly cloudy, with a low around 42. Southwest wind 7 to 11 mph. Chance of precipitation is 70%. 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. Patchy fog before 7am. Otherwise, partly sunny, with a high near 58. West southwest wind 6 to 9 mph becoming north northwest in the morning. New precipitation amounts of less than a tenth of an inch possible.

Sunday Night
Mostly clear, with a low around 40.

Monday
Partly sunny, with a high near 58.

Monday Night
Partly cloudy, with a low around 41.

Tuesday
Mostly sunny, with a high near 62.

Tuesday Night
Partly cloudy, with a low around 43.

Wednesday
A chance of rain. Partly sunny, with a high near 55.

Wednesday Night
Rain likely. Mostly cloudy, with a low around 42.

Thursday
A chance of rain. Partly sunny, with a high near 54.

Thursday Night
A chance of rain. Mostly cloudy, with a low around 42.

Friday
Rain likely. Mostly cloudy, with a high near 51.

Bay City News Service contributed to this report.