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

Heavy Rainfall in the Southern Plains and Mississippi Valley; Thunderstorms in Eastern Colorado on Thursday

A multiple day heavy rainfall event will begin to set up from the Southern Plains into the Mississippi Valley Thursday, peaking in intensity over the holiday weekend. Widely scattered thunderstorms are expected to develop across eastern Colorado Thursday afternoon and evening. Large hail will be the primary hazard. Read More >

Hazardous Weather Conditions

Current conditions at

Knoxville, McGhee Tyson Airport (KTYS)

Lat: 35.82°NLon: 83.99°WElev: 981ft.

Mostly Cloudy

70°F

21°C

Humidity 84%
Wind Speed NE 10 G 18 mph
Barometer 30.07 in (1017.1 mb)
Dewpoint 65°F (18°C)
Visibility 10.00 mi
Last update 21 May 12:53 am EDT
Extended Forecast for

Knoxville, McGhee Tyson Airport TN

  • Overnight

    Overnight: A chance of showers and thunderstorms. Mostly cloudy, with a low around 66. Calm wind. Chance of precipitation is 50%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 66 °F

    Chance
    Showers

  • Thursday

    Thursday: Showers, with thunderstorms also possible after 11am. High near 81. Calm wind becoming east around 5 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.

    High: 81 °F

    Showers

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 64. Northeast wind around 5 mph becoming calm after midnight. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 64 °F

    Chance
    T-storms then
    Chance
    Showers

  • Friday

    Friday: Showers, with thunderstorms also possible after 11am. High near 82. Light and variable wind becoming southwest 5 to 10 mph in the afternoon. Chance of precipitation is 90%.

    High: 82 °F

    Showers

  • Friday Night

    Friday Night: Showers and possibly a thunderstorm. Low around 66. South wind 5 to 10 mph. Chance of precipitation is 100%.

    Low: 66 °F

    Showers

  • Saturday

    Saturday: Showers, with thunderstorms also possible after 11am. High near 81. Southwest wind 5 to 10 mph. Chance of precipitation is 100%.

    High: 81 °F

    Showers

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 64. Southwest wind around 5 mph becoming calm. Chance of precipitation is 40%.

    Low: 64 °F

    Chance
    Showers

  • Sunday

    Sunday: Showers likely, then showers and possibly a thunderstorm after 8am. High near 83. Chance of precipitation is 80%.

    High: 83 °F

    Showers

  • Sunday Night

    Sunday Night: Showers and possibly a thunderstorm before 2am, then a chance of showers. Low around 65. Chance of precipitation is 80%.

    Low: 65 °F

    Showers

Detailed Forecast

Overnight
A chance of showers and thunderstorms. Mostly cloudy, with a low around 66. Calm wind. Chance of precipitation is 50%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Thursday
Showers, with thunderstorms also possible after 11am. High near 81. Calm wind becoming east around 5 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Thursday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 64. Northeast wind around 5 mph becoming calm after midnight. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Friday
Showers, with thunderstorms also possible after 11am. High near 82. Light and variable wind becoming southwest 5 to 10 mph in the afternoon. Chance of precipitation is 90%.
Friday Night
Showers and possibly a thunderstorm. Low around 66. South wind 5 to 10 mph. Chance of precipitation is 100%.
Saturday
Showers, with thunderstorms also possible after 11am. High near 81. Southwest wind 5 to 10 mph. Chance of precipitation is 100%.
Saturday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 64. Southwest wind around 5 mph becoming calm. Chance of precipitation is 40%.
Sunday
Showers likely, then showers and possibly a thunderstorm after 8am. High near 83. Chance of precipitation is 80%.
Sunday Night
Showers and possibly a thunderstorm before 2am, then a chance of showers. Low around 65. Chance of precipitation is 80%.
Memorial Day
A chance of showers, then showers and possibly a thunderstorm after 8am. High near 82. Chance of precipitation is 80%.
Monday Night
Showers and thunderstorms. Low around 65. Chance of precipitation is 80%.
Tuesday
Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 83. Chance of precipitation is 70%.
Tuesday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 65.
Wednesday
Showers and thunderstorms likely. Partly sunny, with a high near 84. Chance of precipitation is 70%.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Knoxville, McGhee Tyson Airport TN
 35.83°N 83.98°W (Elev. 961 ft)
Last Update:
1:06 am EDT May 21, 2026
Forecast Valid:
1am EDT May 21, 2026-6pm EDT May 27, 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