April 23, 2023: A CME hit Earth’s magnetic field on April 23rd, a direct hit that sparked a severe G4-class geomagnetic storm. Northern lights spilled out of the Arctic Circle all the way down to the US-Mexico border (+29.5N):

“I was out shooting the night sky in the Big Bend region of Texas when I saw the alerts of the severe geomagnetic storm,” says photographer Brad Dwight. “I decided to point my camera north just to see if I could see anything. These pillars exploded into view.”

In neighboring Arizona, David Blanchard made a video of the geomagnetic glow:

“It was a spectacular display here in Flagstaff (+35.2N),” says Blanchard. “The video covers the period 0354-0512 UTC on April 24th.”

Other notable low-latitude sightings in the USA include southern California (+32.5N), Arizona (+34.8N), Arkansas (+35.1 N), Colorado (+38N), Utah (+40.8N), Oklahoma (+36.3N), North Carolina (+36.2N), Tennessee (+35.4N), New Mexico (+35.9N) and Nebraska (+40.6N).

There were advantages to being a bit farther north. Consider this photo taken by Katie Korbuszewski of Helena, Montana (+46.5N):

“This was the first time I have seen Northern Lights,” she says. “They became a bright dome right above my head and all around. You could visibly see cars and people in the gravel lot that had previously been obscured by darkness. I used my iPhone 12 mini on the night mode setting with an exposure of 3 seconds.”

“I thank my dad Paul Korbuszewski, an avid astronomer who checks Spaceweather.com like one checks the NASDAQ,” says Katie. “He gave me a call from Western Washington to tell me where to look!”

Auroras over Sturgis, South Dakota (+44.4N), were so big and intense, they surrounded onlookers in all directions. “They were everywhere,” says photographer Chris Yushta, “so I took a 360 degree panorama and turned it into a Panosphere.”

“The auroras were incredible!” says Yushta.

Did you miss the storm? Subscribers to our Space Weather Alert service received instant text messages when the CME arrived and when the subsequent storm erupted. Solar Cycle 25 is just getting started, so this will happen again. Make sure you don’t miss the next storm!

April 21, 2023: Earth is in the strike zone. On April 21st, a large magnetic filament snaking across the sun’s southern hemisphere exploded, hurling a cloud of debris in our direction. This movie from NASA’s Solar Dynamics Observatory shows what happened:

Soon after the eruption, the US Air Force reported strong Type II and Type IV solar radio bursts. These are natural shortwave emissions produced by shock waves preceding the CME as it passes through the sun’s atmosphere. Drift rates in the Type II burst suggested a CME velocity of about 580 km/s (1.3 million mph).

Images from SOHO coronagraphs have since confirmed the CME. It is a “halo CME” heading straight for Earth:

Models from NASA and from NOAA agree: the CME should reach Earth during the early hours of April 24th between the hours of 00:00 and 12:00 UT. The impact could spark G1- (Minor) to G2-class (Moderate) geomagnetic storms, with a slight chance of G3 (Strong). Aurora alerts: SMS Text.

A BURST OF STATIC FROM THE SUN: The explosion that hurled a CME toward Earth on April 21st also illuminated our planet with an intense burst of shortwave radio static. Amateur astronomer Thomas Ashcraft of New Mexico recorded the outburst:

“Few solar radio bursts show as hot purple on my spectrograph, but this one ‘rang the bell’,” he says. “Here is an audio recording in stereo with 22 MHz in one channel and 19 MHz in the other.”

The static in Ashcraft’s recording, which washes over the listener like a slow ocean wave, is naturally produced. Astronomers classify it as a Type V solar radio burst caused by energetic beams of electrons ray-gunning through the sun’s atmosphere. The electrons were accelerated by the same underlying explosion that hurled a CME toward Earth.

Solar radio bursts are an underappreciated form of space weather. We often talk about radio blackouts, which happen when solar flares ionize the top of Earth’s atmosphere. A radio blackout suppresses the normal propagation of terrestrial radio signals. Solar radio bursts, on the other hand, produce a radio drownout. Intense static from the sun overwhelms normal transmissions, drowning out the voices radio operators are trying to hear.

Solar radio bursts will happen more and more often as Solar Cycle 25 intensifies. You can hear them youself using a RadioJOVE radio telescope kit from NASA.

April 13: 2023: Solar Maximum is coming–maybe this year. New research by a leading group of solar physicists predicts maximum sunspot activity in late 2023 or early 2024, a full year earlier than other forecasts.

“This is based on our work with the Termination Event,” explains Scott McIntosh, lead author of a paper describing the prediction, published in the January 2023 edition of Frontiers in Astronomy and Space Sciences.

Above: The red curve shows McIntosh et al’s new prediction of an early Solar Max. 

The “Termination Event” is a relatively new concept in solar physics. It is a period of time on the sun as short as one month when magnetic fields from one solar cycle abruptly die (they are “terminated”) allowing magnetic fields from the next solar cycle to take over. After a Termination Event, the new solar cycle skyrockets.

McIntosh and colleagues have studied termination events for many solar cycles, and they have discovered that its timing can predict the future. “Our latest work pinpoints the Termination Event between Solar Cycle 24 and Solar Cycle 25 at mid-Dec. 2021,” explains McIntosh. “This tells us about the size and date of the next solar maximum.”

According to their paper, Solar Max is coming between late 2023 and mid 2024, with a peak total monthly sunspot number of 184±63 (95% confidence). This means Solar Cycle 25 could be twice as strong as old Solar Cycle 24, which peaked back in 2014. 

Above: The sun’s polar magnetic field (red=N, blue=S) is weakening and will soon flip

Their forecast jibes with another big event now underway. The sun’s global magnetic field is about to flip. This happens near the peak of every solar cycle. Magnetic fields near the sun’s poles weaken, change sign, and start growing again in the opposite direction. It’s like taking a bar magnet from your refrigerator and flipping it upside down–except this bar magnet is as big as a star.

Measurements from Stanford’s Wilcox Solar Observatory (pictured above) confirm that the weakening is underway now, with polar magnetic fields probably crossing zero in no more than a few months. “Historically the zero crossing precedes actual sunspot number maximum by 6 to 12 months,” says McIntosh, “so this is in accord with our prediction of an early Solar Max.”

This forecast is about to be tested, with confirmation as little as 6 to 12 months away. Stay tuned for Solar Max.

This story was brought to you by Spaceweather.com