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

Flooding Risks from Tropical Moisture Across the Southeast and Southwest

Tropical moisture from Isaias and Rachel will impact portions of the Southeast and Southwest this weekend. Flash flooding, strong winds and even a threat for severe thunderstorms and tornadoes are possible. Meanwhile, strong winds and dry fuels are raising fire weather concerns across the central Great Basin and western High Plains. Across the northern Rockies, first winter storm of the season. Read More >

Current conditions at

Selinsgrove Penn Valley Airport (KSEG)

Lat: 40.82°NLon: 76.87°WElev: 443ft.

A Few Clouds

55°F

13°C

Humidity 90%
Wind Speed Calm
Barometer 30.41 in (1029.8 mb)
Dewpoint 52°F (11°C)
Visibility 10.00 mi
Last update 10 Oct 10:53 pm EDT
Extended Forecast for

Northumberland PA

  • Tonight

    Tonight: A chance of rain, mainly after 2am. Mostly cloudy, with a low around 52. Calm wind. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 52 °F

    Chance Rain

  • Sunday

    Sunday: Rain, with thunderstorms also possible after 2pm. High near 64. East wind 3 to 7 mph. Winds could gust as high as 20 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.

    High: 64 °F

    Rain

  • Sunday Night

    Sunday Night: A chance of rain and thunderstorms before 2am, then a slight chance of showers between 2am and 3am. Patchy fog after midnight. Otherwise, cloudy, with a low around 58. Light north wind. Chance of precipitation is 50%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 58 °F

    Chance
    Showers and
    Patchy Fog

  • Columbus Day

    Columbus Day: Mostly cloudy through mid morning, then gradual clearing, with a high near 72. North wind 3 to 6 mph.

    High: 72 °F

    Becoming
    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 55. Calm wind.

    Low: 55 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Partly sunny, with a high near 76.

    High: 76 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 61.

    Low: 61 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 73.

    High: 73 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 52.

    Low: 52 °F

    Partly Cloudy

Detailed Forecast

Tonight
A chance of rain, mainly after 2am. Mostly cloudy, with a low around 52. Calm wind. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.
Sunday
Rain, with thunderstorms also possible after 2pm. High near 64. East wind 3 to 7 mph. Winds could gust as high as 20 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.
Sunday Night
A chance of rain and thunderstorms before 2am, then a slight chance of showers between 2am and 3am. Patchy fog after midnight. Otherwise, cloudy, with a low around 58. Light north wind. Chance of precipitation is 50%. New precipitation amounts between a quarter and half of an inch possible.
Columbus Day
Mostly cloudy through mid morning, then gradual clearing, with a high near 72. North wind 3 to 6 mph.
Monday Night
Partly cloudy, with a low around 55. Calm wind.
Tuesday
Partly sunny, with a high near 76.
Tuesday Night
Partly cloudy, with a low around 61.
Wednesday
Mostly sunny, with a high near 73.
Wednesday Night
Partly cloudy, with a low around 52.
Thursday
Mostly sunny, with a high near 66.
Thursday Night
A chance of showers. Mostly cloudy, with a low around 50. Chance of precipitation is 40%.
Friday
A chance of showers. Mostly cloudy, with a high near 65. Chance of precipitation is 50%.
Friday Night
A chance of showers. Mostly cloudy, with a low around 48. Chance of precipitation is 30%.
Saturday
Partly sunny, with a high near 59.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Northumberland PA
 40.89°N 76.79°W (Elev. 482 ft)
Last Update:
9:41 pm EDT Oct 10, 2026
Forecast Valid:
11pm EDT Oct 10, 2026-6pm EDT Oct 17, 2026
 
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