CHEYENNE, Wyo. — The National Oceanic and Atmospheric Administration has issued a severe G4 geomagnetic storm watch for Cheyenne, set for the evening of May 10. This alert follows significant solar activity, including multiple solar flares and coronal mass ejections starting from May 8.
Geomagnetic storms, triggered by eruptions of plasma and magnetic fields from the sun’s corona, can pose threats to critical infrastructure. They can disrupt communications, navigation and even the electric power grid. NOAA has informed operators of these systems to prepare for potential impacts.
For the night sky enthusiasts, the storm might also dazzle, with auroras visible as far south as Alabama and Northern California.
The SWPC reported that a large sunspot cluster, 16 times the diameter of Earth, has been particularly active, producing several strong flares. These flares are linked to earth-directed coronal mass ejections, which are expected to hit as early as midday Friday, May 10. The CMEs are anticipated to merge and arrive on Earth by late on May 10 or early on May 11.
The best viewing times for the aurora borealis are currently projected from 8 p.m. May 10 to 2 a.m. May 11, with Kp index levels hitting 7.0–8.33 in that time frame. The timing for aurora is very difficult to predict and could fluctuate significantly.
Readers should also be aware of potential disruptions to satellite navigation and radio communications.
This is the first G4 geomagnetic storm watch issued by the NOAA since January 2005. The last severe storm, on March 23, 2024, and the extreme conditions of the Halloween Storms in October 2003 had significant impacts, including power outages and damage to infrastructure.
With only three severe storms noted in this solar cycle, which began in December 2019, the upcoming event is drawing considerable attention from both the public and specialists in the field.
