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

Harlan, Harlan Municipal Airport (KHNR)

Lat: 41.58°NLon: 95.34°WElev: 1230ft.

Fog

45°F

7°C

Humidity 100%
Wind Speed N 5 mph
Barometer 29.79 in
Dewpoint 45°F (7°C)
Visibility 0.25 mi
Wind Chill42°F (6°C)
Last update 25 Dec 6:15 pm CST
Extended Forecast for

Portsmouth IA

Dense Fog Advisory December 25, 06:37pm until December 25, 08:00pm
Click here for hazard details and duration
...
  •  
    Dense Fog Advisory December 25, 06:37pm until December 25, 08:00pm

    NOW until 8:00pm Thu

    Dense Fog Advisory

  • Tonight

    Low: 39 °F

    Slight Chance
    Drizzle and
    Dense Fog
    then Dense
    Fog

  • Friday

    Friday: Mostly sunny, with a high near 53. West wind around 6 mph becoming calm in the afternoon.

    High: 53 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 38. Calm wind becoming south southeast around 6 mph after midnight.

    Low: 38 °F

    Mostly Cloudy

  • Saturday

    Saturday: Mostly cloudy, with a high near 57. South southeast wind 5 to 10 mph, with gusts as high as 16 mph.

    High: 57 °F

    Mostly Cloudy

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 26. Light and variable wind becoming north 11 to 16 mph after midnight. Winds could gust as high as 23 mph.

    Low: 26 °F

    Mostly Cloudy

  • Sunday

    Sunday: A chance of rain and snow before noon, then a slight chance of snow. Mostly cloudy, with a high near 34. Breezy, with a north northwest wind 18 to 24 mph, with gusts as high as 34 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

    High: 34 °F

    Breezy.
    Chance
    Rain/Snow
    then Slight
    Chance Snow

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 7. Blustery, with a north northwest wind 20 to 23 mph, with gusts as high as 32 mph.

    Low: 7 °F

    Partly Cloudy
    and Blustery

  • Monday

    Monday: Sunny, with a high near 22. Blustery, with a north northwest wind 10 to 18 mph, with gusts as high as 28 mph.

    High: 22 °F

    Sunny and
    Blustery then
    Sunny

Detailed Forecast

Tonight
A slight chance of drizzle before 9pm. Widespread dense fog, mainly before 1am. Otherwise, cloudy, then gradually becoming partly cloudy, with a low around 39. Southeast wind around 6 mph becoming light and variable.
Friday
Mostly sunny, with a high near 53. West wind around 6 mph becoming calm in the afternoon.
Friday Night
Mostly cloudy, with a low around 38. Calm wind becoming south southeast around 6 mph after midnight.
Saturday
Mostly cloudy, with a high near 57. South southeast wind 5 to 10 mph, with gusts as high as 16 mph.
Saturday Night
Mostly cloudy, with a low around 26. Light and variable wind becoming north 11 to 16 mph after midnight. Winds could gust as high as 23 mph.
Sunday
A chance of rain and snow before noon, then a slight chance of snow. Mostly cloudy, with a high near 34. Breezy, with a north northwest wind 18 to 24 mph, with gusts as high as 34 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.
Sunday Night
Partly cloudy, with a low around 7. Blustery, with a north northwest wind 20 to 23 mph, with gusts as high as 32 mph.
Monday
Sunny, with a high near 22. Blustery, with a north northwest wind 10 to 18 mph, with gusts as high as 28 mph.
Monday Night
Mostly clear, with a low around 10. Northwest wind 5 to 8 mph becoming southwest after midnight.
Tuesday
Mostly sunny, with a high near 39. West southwest wind 6 to 10 mph, with gusts as high as 18 mph.
Tuesday Night
Partly cloudy, with a low around 20. West northwest wind around 7 mph.
Wednesday
Mostly sunny, with a high near 35. West northwest wind 6 to 10 mph becoming south southwest in the afternoon. Winds could gust as high as 17 mph.
Wednesday Night
Partly cloudy, with a low around 14. South southwest wind 6 to 8 mph becoming north after midnight.
New Year's Day
Mostly sunny, with a high near 29. North northeast wind 6 to 9 mph.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Portsmouth IA
 41.65°N 95.5°W (Elev. 1319 ft)
Last Update:
6:05 pm CST Dec 25, 2025
Forecast Valid:
6pm CST Dec 25, 2025-6pm CST Jan 1, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation