Concord, New Hampshire – A rare G4 (Severe) geomagnetic storm is expected to affect Earth on Jan. 20, prompting increased monitoring of power grids and critical infrastructure across New Hampshire and Vermont, according to federal space weather officials.
The National Oceanic and Atmospheric Administration’s Space Weather Prediction Center reports that a coronal mass ejection (CME) launched from the Sun late last week is forecast to arrive late Sunday into Monday. G4-level geomagnetic storms are uncommon and can disrupt power transmission systems, satellite operations, GPS accuracy, and some radio communications, particularly in higher-latitude regions such as northern New England.
New Hampshire and Vermont are considered more vulnerable to geomagnetic effects due to their latitude, mountainous terrain, and reliance on long-distance transmission lines serving rural communities. While NOAA officials emphasize that widespread power outages are not expected, utilities typically increase monitoring and take precautionary measures during severe space weather events to protect transformers and maintain grid stability.
For most residents, the solar storm itself will not be noticeable. Experts note that geomagnetic activity can reduce the power grid’s margin for error, especially during periods of elevated demand. Grid operators may implement load balancing or equipment protection protocols if conditions intensify.
Cell phone service and internet connectivity are expected to remain largely unaffected. However, minor GPS inaccuracies are possible, particularly affecting aviation, surveying, and precision timing systems.
As a visible side effect, auroras may be visible across northern New Hampshire and Vermont, with the potential for broader visibility if geomagnetic activity strengthens beyond current forecasts.
NOAA forecasters say geomagnetic activity could persist at lower levels into Tuesday.
