National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

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

Current conditions at

Nevada County Air Park (KGOO)

Lat: 39.224028°NLon: 121.003083°WElev: 3154.0ft.

Mist

45°F

7°C

Humidity 100%
Wind Speed N 0 MPH
Barometer 29.68 in (1005.08 mb)
Dewpoint 45°F (7°C)
Visibility 3.00 mi
Last update 24 Dec 09:35 AM PST
Extended Forecast for

Grass Valley CA

Flood Watch December 24, 09:49am until December 26, 04:00pm
Flood Advisory until December 24, 01:30pm
High Wind Warning December 24, 09:49am until December 25, 04:00pm
Click here for hazard details and duration
Flood Watch
Flood Advisory
High Wind Warning
  •  
    Flood Watch December 24, 09:49am until December 26, 04:00pm
    Flood Advisory until December 24, 01:30pm
    High Wind Warning December 24, 09:49am until December 25, 04:00pm

    NOW: Multiple hazards in effect

    Click HERE for Details

  • Today

    High: 52 °F

    Rain

  • Tonight

    Tonight: Showers and possibly a thunderstorm, mainly before 4am, then rain after 4am. Some of the storms could produce heavy rainfall. Low around 42. South southeast wind 13 to 18 mph, with gusts as high as 39 mph. Chance of precipitation is 100%. New rainfall amounts between three quarters and one inch possible.

    Low: 42 °F

    Heavy Rain

  • Christmas Day

    Christmas Day: Rain before 10am, then showers and possibly a thunderstorm between 10am and 1pm, then rain after 1pm. Some of the storms could produce heavy rainfall. High near 48. South wind 15 to 18 mph, with gusts as high as 39 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.

    High: 48 °F

    Heavy Rain

  • Thursday Night

    Thursday Night: Rain before 7pm, then showers and possibly a thunderstorm between 7pm and 10pm, then rain after 10pm. Some of the storms could produce heavy rainfall. Low around 38. South wind 14 to 16 mph, with gusts as high as 34 mph. Chance of precipitation is 100%. New precipitation amounts between 1 and 2 inches possible.

    Low: 38 °F

    Heavy Rain

  • Friday

    Friday: Rain. High near 46. South southeast wind 9 to 11 mph, with gusts as high as 25 mph. Chance of precipitation is 100%.

    High: 46 °F

    Rain

  • Friday Night

    Friday Night: Rain, mainly before 4am. Low around 35. Chance of precipitation is 80%.

    Low: 35 °F

    Rain

  • Saturday

    Saturday: A 30 percent chance of rain, mainly before 10am. Mostly sunny, with a high near 50.

    High: 50 °F

    Chance Rain

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 33.

    Low: 33 °F

    Mostly Clear

Detailed Forecast

Today
Rain. High near 52. South southeast wind 9 to 14 mph, with gusts as high as 32 mph. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch possible.
Tonight
Showers and possibly a thunderstorm, mainly before 4am, then rain after 4am. Some of the storms could produce heavy rainfall. Low around 42. South southeast wind 13 to 18 mph, with gusts as high as 39 mph. Chance of precipitation is 100%. New rainfall amounts between three quarters and one inch possible.
Christmas Day
Rain before 10am, then showers and possibly a thunderstorm between 10am and 1pm, then rain after 1pm. Some of the storms could produce heavy rainfall. High near 48. South wind 15 to 18 mph, with gusts as high as 39 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.
Thursday Night
Rain before 7pm, then showers and possibly a thunderstorm between 7pm and 10pm, then rain after 10pm. Some of the storms could produce heavy rainfall. Low around 38. South wind 14 to 16 mph, with gusts as high as 34 mph. Chance of precipitation is 100%. New precipitation amounts between 1 and 2 inches possible.
Friday
Rain. High near 46. South southeast wind 9 to 11 mph, with gusts as high as 25 mph. Chance of precipitation is 100%.
Friday Night
Rain, mainly before 4am. Low around 35. Chance of precipitation is 80%.
Saturday
A 30 percent chance of rain, mainly before 10am. Mostly sunny, with a high near 50.
Saturday Night
Mostly clear, with a low around 33.
Sunday
Mostly sunny, with a high near 53.
Sunday Night
Mostly clear, with a low around 35.
Monday
Sunny, with a high near 56.
Monday Night
Mostly clear, with a low around 38.
Tuesday
Sunny, with a high near 59.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Grass Valley CA
 39.23°N 121.05°W (Elev. 2657 ft)
Last Update:
9:31 am PST Dec 24, 2025
Forecast Valid:
9am PST Dec 24, 2025-6pm PST Dec 30, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation