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

LOS ALTOS (LOAC1)

Lat: 37.35472°NLon: 122.14167°WElev: 539.0ft.

52°F

11°C

Humidity	83%
Wind Speed	SSW 3 MPH
Barometer	NA
Dewpoint	47°F (8°C)
Visibility	NA
Last update	25 Dec 10:10 PM PST

More Information:

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

Extended Forecast for

2 Miles S Cupertino CA

Flood Watch December 25, 10:31pm until December 26, 10:00pm

Click here for hazard details and duration

Flood Watch

Flood Watch December 25, 10:31pm until December 26, 10:00pm
NOW until 10:00pm Fri
Flood Watch
Tonight
Low: 46 °F
Showers
Likely
Friday
High: 55 °F
Showers
Likely
Friday Night
Low: 43 °F
Chance
Showers
Saturday
High: 53 °F
Slight Chance
Showers then
Mostly Sunny
Saturday Night
Low: 36 °F
Mostly Clear
then Areas
Frost
Sunday
High: 54 °F
Areas Frost
then Sunny
Sunday Night
Low: 36 °F
Clear then
Patchy Frost
Monday
High: 58 °F
Areas Frost
then Sunny

Detailed Forecast

Tonight

Showers likely, mainly after 1am. Mostly cloudy, with a low around 46. South southwest wind 10 to 17 mph, with gusts as high as 32 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

Friday

Showers likely, with thunderstorms also possible after 4pm. Mostly cloudy, with a high near 55. South wind 9 to 11 mph, with gusts as high as 23 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. Mostly cloudy, with a low around 43. South wind around 6 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Saturday

A 20 percent chance of showers before 10am. Mostly sunny, with a high near 53. North northwest wind 3 to 6 mph.

Saturday Night

Areas of frost after 4am. Otherwise, mostly clear, with a low around 36. Light north northeast wind.

Sunday

Areas of frost before 8am. Otherwise, sunny, with a high near 54.

Sunday Night

Patchy frost after midnight. Otherwise, clear, with a low around 36.

Monday

Areas of frost before 8am. Otherwise, sunny, with a high near 58.

Monday Night

Patchy frost after 5am. Otherwise, mostly clear, with a low around 38.