(NEXSTAR) – The northern lights defied expectations over the weekend by appearing in night skies as far south as Florida and Hawaii. We have solar storm activity to thank – and that activity isn't done just yet.
Solar flares and eruptions will likely increase as we reach “solar maximum,” explained Nicola Fox, the director of NASA’s heliophysics division.
The current solar cycle, No. 25, began in December 2019.
"During the Sun’s natural 11-year cycle, the Sun shifts from relatively calm to stormy, then back again," said Fox. "At its most active, called solar maximum, the Sun is freckled with sunspots and its magnetic poles reverse."
All this activity sparks coronal mass ejections, or CMEs, which are essentially explosions of plasma and magnetic material shooting out of the sun. When they hit Earth’s magnetic field, currents send particles flowing to the North and South Poles, and that's what causes the aurora, or northern lights, to appear in our skies. The stronger the geomagnetic storm, the further south the phenomenon is visible.
The peak of this solar cycle is predicted to happen somewhere between November 2024 and March 2026. The best guess we have from NOAA's space weather modeling is July 2025, but it could happen months sooner or later.
As we approach that solar maximum, we can expect more geomagnetic storms to pop up.
The scientists at the Space Weather Prediction Center (SWPC) keep a close eye on active regions of the sun to try and predict broadly what might happen over the next several days or weeks, but it's hard to tell exactly when and how CMEs will hit Earth when they're coming from 90 million miles away. Once they reach about 1 million miles from Earth, scientists can take much more accurate measurements and make good predictions – but the lead time is small, about 15 to 45 minutes.
The severe, G5-level storm that hit Earth Friday night and Saturday morning was the strongest to reach us since 2003. Strong geomagnetic storms can cause more than just pretty lights in the sky – they also can create issues for power infrastructure, communications and navigation.
According to the SWPC's scale, a minor G1 storm can bring the aurora to Maine and Michigan’s Upper Peninsula while a moderate G2 storm can bring them into New York and Idaho. When a storm reaches G3 status, aurora can be viewed as far south as Illinois and Oregon. Should it reach G4 strength, those living in Alabama and northern California may have a chance at seeing the northern lights. Solar activity that causes a G5 storm, like the storm we saw Friday, has been known to make aurora appear in Florida and even southern Texas.
