Aurora viewers will want to keep their eyes on the sky this weekend as solar flares from the Sun are hurling towards Earth.
NOAA has upgraded a geomagnetic solar storm watch from a Level 3 (“moderate”) to a Level 4 (“severe”) as several solar flares have combined. That could grace the northern tier skies with brilliant auroras but also trigger GPS problems, hamper satellite communication, and cause high-frequency radio blackouts.
“Watches at this level are very rare,” NOAA stated in the watch. “This is an unusual event.”
This is the first “severe” Geomagnetic Storm Watch issued since January 2005.
Sunspots merged
Two massive sunspots have recently merged and spit out at least two X-class (largest) and several M-class (second-largest) solar flares. According to NOAA, the explosive acceleration of charged and superheated plasma, known as a coronal mass ejection or CME, speeds through space and expands.
The new sunspot is 16 times the diameter of the Earth.
Another sunspot also released strong CMEs this week and continues to be active. According to NOAA, the bulk of five CMEs will collide with Earth in a glancing blow as early as midday Friday through Sunday.
“These two sunspot clusters are magnetically complex and much larger than Earth. Together they have been the source of frequent M-class flares (minor to moderate),” stated the Space Weather Prediction Center. “RGN 3664 (the combined sunspot region) continues to grow and increase in magnetic complexity and has evolved into a higher threat of increased solar flare risk.”
How flares can set off geomagnetic storms
“Flares are when the sun brightens, and we see the radiation, and that’s kind of the muzzle flash,” explained Professor Peter Becker of George Mason University in an earlier interview. “And then the cannon shot is the coronal mass ejection (CME). So, we can see the flash, but then the coronal mass ejection can go off in some random direction in space, but we can tell when they’re actually going to head towards Earth. And that gives us about 18 hours of warning, maybe 24 hours of warning, before those particles actually get to Earth and start messing with Earth’s magnetic field.”
NOAA warns of a wide area blackout of high frequency radio communications for hours. The geomagnetic storm could also cause widespread voltage irregularities in power systems which trigger false alarms on security devices, cause drag on low earth orbit satellites preventing them from orienting and cause range errors and a loss-of-lock for GPS systems.
Forecast: Will clouds block my aurora viewing?
With current forecasts, this storm may strike Earth late Friday into Saturday morning across North America.
The FOX Forecast Center said the skies look clear for most of the northern U.S. with less than 10% cloud cover expected from the Midwest to the Northwest. However, clouds will be around in the Northeast.
Forecasters estimate these conditions occur for about 60 days over an 11-year solar cycle.
NOAA says scientists have only observed three Severe geomagnetic storms since the current solar cycle started in December 2019.
“The last (observed) Severe geomagnetic storm was on March 23, 2024, and the last Extreme was the Halloween Storms in October 2003,” the SWPC stated. “That G5 (Extreme storm) resulted in power outages in Sweden and damaged power transformers in South Africa.”
X-class solar flares are the largest explosions in the solar system. According to NASA, the biggest X-class flares can produce as much energy as 1 billion atomic bombs. M-class are the second-strongest flares that can cause minor radiation storms and can harm astronauts.
The solar cycle is peaking making solar storms more plentiful
Tree rings and ice cores are evidence of much larger solar superstorms in the past.
In 1859, the great Carrington Event, generally regarded as Earth’s greatest solar storm in recent history, covered nearly the entire planet in aurora. About 14,000 years ago, a solar flare, possibly hundreds of times stronger than the Carrington flare, impacted Earth.
NOAA forecasts the current 11-year solar cycle to peak sometime in 2024 or early 2025 and solar activity is likely to remain active for the next several months or even few years.
