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

SJSU - Mount Diablo Summit Museum Rooftop (SJS02)

Lat: 37.881699°NLon: 121.914173°WElev: 3904.0ft.

41°F

5°C

Humidity	100%
Wind Speed	S 21 MPH
Barometer	NA
Dewpoint	41°F (5°C)
Visibility	NA
Wind Chill	32°F (0°C)
Last update	25 Dec 05:50 PM PST

More Information:

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

Extended Forecast for

2 Miles S Clayton CA

Flood Watch December 25, 06:06pm until December 26, 10:00pm

Click here for hazard details and duration

Flood Watch

Flood Watch December 25, 06:06pm until December 26, 10:00pm
NOW until 10:00pm Fri
Flood Watch
Tonight
Low: 48 °F
Severe
Thunderstorms
then Chance
Showers
Friday
High: 55 °F
Showers
Likely
Friday Night
Low: 43 °F
Chance
Showers
Saturday
High: 52 °F
Partly Sunny
Saturday Night
Low: 38 °F
Mostly Clear
Sunday
High: 50 °F
Sunny
Sunday Night
Low: 37 °F
Mostly Clear
then Patchy
Frost
Monday
High: 52 °F
Patchy Frost
then Sunny

Detailed Forecast

Tonight

Showers and possibly a thunderstorm before 10pm, then a chance of showers. Some of the storms could be severe. Low around 48. South southwest wind around 18 mph, with gusts as high as 34 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

Friday

Showers likely, with thunderstorms also possible after 4pm. Mostly cloudy, with a high near 55. South wind 10 to 18 mph, with gusts as high as 32 mph. Chance of precipitation is 60%. 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 southwest wind around 7 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Saturday

Partly sunny, with a high near 52. North wind around 7 mph.

Saturday Night

Mostly clear, with a low around 38. North northwest wind around 6 mph.

Sunday

Sunny, with a high near 50.

Sunday Night

Patchy frost after 5am. Otherwise, mostly clear, with a low around 37.

Monday

Patchy frost before 7am. Otherwise, sunny, with a high near 52.

Monday Night

Patchy frost before 4am, then areas of frost after 5am. Otherwise, mostly clear, with a low around 36.