NOAA forecasters are predicting a 90 percent chance of geomagnetic storms today and tomorrow, when a fast-moving stream of solar wind is expected to hit Earth’s magnetic field. NOAA has issued a G3 (strong) geomagnetic storm watch for November 2 (UTC) and a G2 (moderate) geomagnetic storm watch for November 3 (UTC), as a recurrent high-speed stream from a coronal hole returns.

“This particular feature was associated with G3 conditions last rotation,” NOAA said. Solar wind speeds could exceed 800 km/s. Sky watchers in the US should be on the alert for auroral displays as far south as Oregon and Illinois. Sky watchers in the USA should be alert for Northern Lights as far south as 40° or 50° N latitude.

In a G3 storm, HF radio may be intermittent. Power systems may require voltage corrections may be required, and the storms could trigger false alarms on some protection devices, according to NOAA. In addition, surface charging may occur on satellite components, drag may increase on low-Earth orbit satellites, and orientation may need to be corrected. Intermittent satellite navigation and low-frequency radio navigation problems may occur.

Spaceweather.com reports that a monster sunspot, AR2443, has more than quadrupled in size since first appearing on October 29 and now stretches more than 175,000 km from end to end. The sunspot’s beta-gamma magnetic field harbors energy that could generate strong M-class solar flares. These could affect Earth as the sunspot rotates into our planets trajectory.

M-class flares can cause brief radio blackouts affecting Earth’s polar regions. Minor radiation storms sometimes follow an M-class flare.