RALEIGH, N.C. (WNCN) — The Space Weather Prediction Center has issued a Geomagnetic Storm Watch as multiple CMEs (coronal mass ejections) are headed toward Earth. On May 7 and May 8, up to five CMEs were spotted coming off the Sun, and as they merge together are expected to impact Earth on Saturday, May 11th. This storm has been classified as a G4 or a severe strength storm. This is the first time since 2005 that a watch has been issued for a G4 storm.
What is a CME?
A CME, or Coronal Mass Ejection, is a cloud of plasma and the accompanying magnetic field that explodes off the surface of the Sun. The Sun is an active star, so explosions or discharges of plasma aren't uncommon, but depending on their strength and how many occur, as well as how they interact with Earth's magnetic field, can have an impact on what we could experience.
What impacts are expected?
A G4 is a severe strength geomagnetic storm, which means more impacts will be felt than a typical geomagnetic storm, but usually north of 45 degrees in latitude. When a G4 impacts Earth, there can be impacts to the power grid as some "voltage control problems and protective systems can mistakenly trip out key assets to the grid" according to the severity scale from the Space Weather Prediction Center. There can also be issues for spacecraft operations, HF (high frequency) radio can have issues, satellite navigation can be impacted for a few hours, and low-frequency radio navigation can be disrupted as well.
As of Friday afternoon, the SWPC now predicts a 75 percent likelihood of strong to severe radio disruptions— which would include an HF (high frequency) radio communication blackout for one to two hours on the sunlit side of the Earth. This could also have minor impacts on satellite navigation and GPS, also on the sunlight side of the Earth.
Power grid issues have occurred with past geomagnetic storms and with a G4 storm expected, power systems, especially in higher latitudes should monitor the storm closely.
Will I see the aurora in NC?
It's possible! With a G4, the most likely locations to see the Aurora in the United States could be as far south as Alabama. This means parts of North Carolina (more than likely western North Carolina) could see the Aurora on Saturday. The best chance to see the Aurora with the naked eye is still a long way from North Carolina, but it is possible with long-exposure photography that we could see it in North Carolina late Friday night and early Saturday morning.
The Bottom Line
Five Coronal Mass Ejections (CMEs) are expected to merge and then impact Earth Saturday, May 11.
A G4 Geomagnetic Storm is expected and therefore a Geomagnetic Storm Watch has been issued. GPS and radio disruptions are likely, especially in northern latitudes.
The Aurora will likely be visible as far south as Alabama, and possibly in parts of western North Carolina. If you want to keep up with the geomagnetic storm, click here.