‘Watch for Severe Geomagnetic Storms’ Released for First Time in Nearly 20 Years – NBC Chicago

The National Weather Service’s Space Weather Prediction Center (SWPC) has issued a “Severe Geomagnetic Storm Watch.” The first such watch was released almost 20 years ago.

According to SWPC, this is the first watch the department has issued since January 2005. The watch comes after forecasters spotted several Earth-bound coronal ejections (CME’s) this week.

At least five CMEs have been observed in recent days, and particles could begin reaching Earth Friday afternoon, according to officials. The Chicago Mercantile Exchange is expected to continue arriving through Sunday, indicating an “unusual event.”

Only three “severe” geomagnetic storms have been observed since the start of the current solar cycle in December 2019. The last G4 storm hit Earth in March, and the last G5 storm struck in October 2003, causing power outages in Sweden, according to SWPC. .

CMEs are large ejections of plasma and magnetized particles from the Sun’s corona,” according to SWPC. These projectiles can expand in size as they approach Earth, and can cause geomagnetic storms upon arrival.

In a geomagnetic storm, particles ejected by the Sun cause disturbances in the Earth’s magnetosphere. Particularly strong storms can affect the Earth’s ionosphere, adding energy in the form of heat that can “increase the density and density distribution in the upper atmosphere, causing additional drag on satellites in low Earth orbit.” According to SWPC.