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

HARLEM (HRLM)

Lat: 48.54333°NLon: 108.83472°WElev: 2358.0ft.

NA

24°F

-4°C

Humidity 96%
Wind Speed ESE 5 MPH
Barometer NA
Dewpoint 23°F (-5°C)
Visibility NA
Wind Chill18°F (-8°C)
Last update 26 Dec 01:00 AM MST
Extended Forecast for

Chinook MT

  • Overnight

    Overnight: A slight chance of freezing rain before 3am. Areas of fog. Otherwise, mostly cloudy, with a low around 21. South southeast wind around 6 mph. Chance of precipitation is 10%.

    Low: 21 °F

    Slight Chance
    Freezing Rain
    and Areas Fog

  • Friday

    Friday: A slight chance of rain between noon and 2pm, then a chance of rain and snow. Patchy fog before 8am. Otherwise, partly sunny, with a high near 40. East southeast wind 5 to 10 mph. Chance of precipitation is 30%. Little or no snow accumulation expected.

    High: 40 °F

    Patchy Fog
    then Chance
    Rain/Snow

  • Friday Night

    Friday Night: A slight chance of rain and snow before 9pm, then a slight chance of snow between 9pm and 11pm. Increasing clouds, with a low around 5. West wind 15 to 20 mph becoming north northwest 9 to 14 mph after midnight. Winds could gust as high as 28 mph. Chance of precipitation is 10%.

    Low: 5 °F

    Slight Chance
    Rain/Snow
    then Partly
    Cloudy

  • Saturday

    Saturday: A 50 percent chance of snow. Mostly cloudy, with a high near 12. Wind chill values as low as -25. Blustery, with a west northwest wind 18 to 24 mph, with gusts as high as 33 mph. New snow accumulation of less than one inch possible.

    High: 12 °F

    Chance Snow
    and Blustery

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around -13. Blustery, with a west northwest wind 13 to 22 mph, with gusts as high as 31 mph.

    Low: -13 °F

    Mostly Cloudy
    and Blustery
    then Partly
    Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 9. West northwest wind 5 to 8 mph becoming calm in the morning.

    High: 9 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around -3. Calm wind becoming west southwest around 6 mph after midnight.

    Low: -3 °F

    Partly Cloudy

  • Monday

    Monday: Partly sunny, with a high near 32. West wind 7 to 11 mph, with gusts as high as 18 mph.

    High: 32 °F

    Partly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 20.

    Low: 20 °F

    Mostly Cloudy

Detailed Forecast

Overnight
A slight chance of freezing rain before 3am. Areas of fog. Otherwise, mostly cloudy, with a low around 21. South southeast wind around 6 mph. Chance of precipitation is 10%.
Friday
A slight chance of rain between noon and 2pm, then a chance of rain and snow. Patchy fog before 8am. Otherwise, partly sunny, with a high near 40. East southeast wind 5 to 10 mph. Chance of precipitation is 30%. Little or no snow accumulation expected.
Friday Night
A slight chance of rain and snow before 9pm, then a slight chance of snow between 9pm and 11pm. Increasing clouds, with a low around 5. West wind 15 to 20 mph becoming north northwest 9 to 14 mph after midnight. Winds could gust as high as 28 mph. Chance of precipitation is 10%.
Saturday
A 50 percent chance of snow. Mostly cloudy, with a high near 12. Wind chill values as low as -25. Blustery, with a west northwest wind 18 to 24 mph, with gusts as high as 33 mph. New snow accumulation of less than one inch possible.
Saturday Night
Partly cloudy, with a low around -13. Blustery, with a west northwest wind 13 to 22 mph, with gusts as high as 31 mph.
Sunday
Mostly sunny, with a high near 9. West northwest wind 5 to 8 mph becoming calm in the morning.
Sunday Night
Partly cloudy, with a low around -3. Calm wind becoming west southwest around 6 mph after midnight.
Monday
Partly sunny, with a high near 32. West wind 7 to 11 mph, with gusts as high as 18 mph.
Monday Night
Mostly cloudy, with a low around 20.
Tuesday
Partly sunny, with a high near 38.
Tuesday Night
A slight chance of rain and snow. Mostly cloudy, with a low around 15.
Wednesday
A slight chance of rain and snow. Mostly cloudy, with a high near 29.
Wednesday Night
A slight chance of snow. Mostly cloudy, with a low around 9.
New Year's Day
A slight chance of snow. Mostly cloudy, with a high near 26.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Chinook MT
 48.59°N 109.26°W (Elev. 2408 ft)
Last Update:
1:22 am MST Dec 26, 2025
Forecast Valid:
2am MST Dec 26, 2025-6pm MST Jan 1, 2026
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation