Atmospheric River Bringing Heavy Rain to Southern California and Heavy Snow to the Sierra Nevadas

A strong atmospheric river will continue heavy rain over southern California through Friday. The heaviest rainfall is ongoing today in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall has begun over the Sierra Nevada Mountains and will continue through Friday. Travel will become increasingly difficult over the passes due to snow and strong winds. Read More >

Hazardous Weather Conditions

Flood Watch until December 26, 10:00 PM PST

Current conditions at

LA HONDA (LAHC1)

Lat: 37.30523°NLon: 122.25525°WElev: 804.0ft.

51°F

11°C

Humidity	91%
Wind Speed	SW 5 MPH
Barometer	NA
Dewpoint	48°F (9°C)
Visibility	NA
Last update	26 Dec 12:07 AM PST

More Information:

Local Forecast Office More Local Wx 3 Day History Hourly Weather Forecast

Extended Forecast for

4 Miles S Portola Valley CA

Flood Watch December 26, 12:19am until December 26, 10:00pm

Click here for hazard details and duration

Flood Watch

Flood Watch December 26, 12:19am until December 26, 10:00pm
NOW until 10:00pm Fri
Flood Watch
Overnight
Low: 48 °F
Showers
Likely
Friday
High: 55 °F
Showers
Likely
Friday Night
Low: 48 °F
Showers
Likely
Saturday
High: 54 °F
Slight Chance
Showers
Saturday Night
Low: 41 °F
Mostly Clear
Sunday
High: 55 °F
Sunny
Sunday Night
Low: 41 °F
Mostly Clear
Monday
High: 58 °F
Sunny

Detailed Forecast

Overnight

Showers likely, mainly between 2am and 5am. Mostly cloudy, with a low around 48. South southwest wind 10 to 13 mph, with gusts as high as 29 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Friday

Showers likely before 4pm, then showers likely and possibly a thunderstorm between 4pm and 5pm, then a chance of showers and thunderstorms after 5pm. Mostly cloudy, with a high near 55. South wind 7 to 11 mph, with gusts as high as 26 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Friday Night

A chance of showers and thunderstorms before 8pm, then showers likely and possibly a thunderstorm between 8pm and 10pm, then a chance of showers after 10pm. Mostly cloudy, with a steady temperature around 48. Light and variable wind becoming west northwest around 5 mph after midnight. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Saturday

A 20 percent chance of showers. Mostly sunny, with a high near 54. North northwest wind 5 to 7 mph.

Saturday Night

Mostly clear, with a low around 41. Calm wind.

Sunday

Sunny, with a high near 55.

Sunday Night

Mostly clear, with a low around 41.

Monday

Sunny, with a high near 58.

Monday Night

Clear, with a low around 43.