Nashville, Tennessee – A G4 (Severe) geomagnetic storm, in effect for Jan. 20, is expected to reach Earth as a sharp Arctic cold outbreak moves into the Tennessee Valley, prompting utilities to closely monitor power systems during a period of elevated demand.
The National Oceanic and Atmospheric Administration’s Space Weather Prediction Center says a coronal mass ejection, or CME, launched from the Sun late last week is forecast to arrive late Sunday into Monday. While the Tennessee Valley lies farther south than regions most exposed to geomagnetic effects, G4 storms can still influence large-scale power transmission systems, satellite operations, GPS accuracy, and radio communications.
The storm watch affects the broader Tennessee Valley region, including Tennessee, northern Alabama, northern Mississippi, southern Kentucky, and portions of eastern Arkansas. Officials emphasize that widespread power outages are not expected, but the timing is notable as Arctic air is forecast to bring hard freezes, single-digit wind chills, and increased heating demand across the region.
For most residents, the solar storm itself will not be noticeable. Experts explain that the concern centers on grid strain during extreme cold, when electricity usage spikes and utilities operate with less flexibility. Even minor disruptions can have greater consequences when temperatures drop well below freezing.
Power providers typically increase monitoring during geomagnetic storms and may take precautionary measures to protect equipment and maintain grid stability. Residents are encouraged to follow standard cold-weather preparedness steps, including keeping devices charged, protecting pipes from freezing, and checking on vulnerable neighbors.
Cell phone service and internet connectivity are expected to remain largely unaffected.
As a secondary effect, auroras may be visible farther north of the region, though limited visibility is possible in northern portions of the Tennessee Valley if storm conditions intensify.
Geomagnetic activity could taper off into Tuesday, even as cold conditions persist across the central and eastern United States.
