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NOAA: 'Strong' geomagnetic storms and auroras continue through Tuesday

On Friday, May 12, 2023, the strongest geomagnetic storm in over two decades hit Earth, causing radio blackouts and extending the northern lights to the southern United States.

As of Monday, May 15, 2023, officials from NOAA’s Space Weather Prediction Center (SWPC) have warned that these geomagnetic solar storms, caused by eruptions from the Sun, are not yet over.

Strong geomagnetic storm warning remains in effect

The SWPC issued a G3, or “strong,” geomagnetic storm warning that remained in effect until 2 a.m. ET on Monday.

While the likelihood of stronger storms has decreased, and conditions are expected to gradually improve throughout the day, the center’s forecast indicates that moderate to strong geomagnetic storms are still likely on Monday, with minor storms possible on Tuesday.

High solar activity and solar flares

The SWPC also reported that “solar activity is expected to be at high levels,” with more M-class and X-class flares anticipated, primarily due to the flare potential of Region 3664.

Another moderate X-class solar flare, the strongest class of these solar bursts, was recently recorded.

“Flares of this magnitude are not frequent,” the SWPC representatives stated, warning that “users of high frequency (HF) radio signals may experience temporary degradation or complete loss of signal on much of the sunlit side of Earth.”

Sunspot Regions 3664 and 3663

The flares originated from Sunspot Region 3664, a massive area of the Sun responsible for many of the flares and coronal mass ejections (CMEs) that led to the weekend’s extreme geomagnetic storm.

This spot remains “the most complex and active on the disk,” according to NOAA, and is so large that it can be seen from Earth by people wearing eclipse glasses, measuring approximately 124,000 miles across.

Sunspot Region 3664 has been active alongside Region 3663, and together, they are considered “magnetically complex and much larger than Earth,” as stated by NOAA.

Continued CMEs and minor solar radiation storms

Coronal Mass Ejections (CMEs), which are large bursts from the sun’s atmosphere filled with plasma and magnetic fields that lead to geomagnetic storms, are expected to continue throughout Monday and fuel G3 activity.

NOAA forecasts that “continuing, but weaker CME influences are anticipated to decrease responses down to unsettled to G1 (Minor) levels on May 14, 2023.”

Minor solar radiation storms are also expected in the same timeframe, along with more radio blackouts. Some of these blackouts could be considered “strong” events, depending on the solar flares that erupt.

Auroras visible across the continental United States

Weather permitting, auroras will be visible again tonight over most of the continental United States. This spectacular display of lights is a direct result of the ongoing geomagnetic storm.

The threat of additional strong solar flares and CMEs, which ultimately result in spectacular aurora displays, will persist until the large and magnetically complex sunspot cluster, NOAA Region 3664, rotates out of view of the Earth. This is expected to occur by Tuesday, May 14, 2024.

As the geomagnetic storm continues to impact Earth, officials urge the public to stay informed and prepared for potential disruptions to radio communications and other technological systems.

Understanding geomagnetic solar storms

Geomagnetic storms are disturbances in the Earth’s magnetic field caused by the interaction between the solar wind and the planet’s magnetosphere. These storms can have significant impacts on technology, infrastructure, and even human health.

Causes of geomagnetic storms

Geomagnetic storms typically originate from the Sun. They are caused by two main phenomena:

  • Coronal Mass Ejections (CMEs): Massive bursts of plasma and magnetic fields ejected from the Sun’s surface.
  • Solar Flares: Intense eruptions of electromagnetic radiation from the Sun’s surface.

When these events occur, they send charged particles streaming towards Earth at high speeds, which can take anywhere from one to five days to reach our planet.

Effects on Earth’s magnetic field

As the charged particles from CMEs and solar flares reach Earth, they interact with the planet’s magnetic field. This interaction causes the magnetic field lines to become distorted and compressed, leading to fluctuations in the strength and direction of the magnetic field.

Impacts on technology and infrastructure

Geomagnetic storms can have significant impacts on various aspects of modern technology and infrastructure:

  • Power Grids: Strong geomagnetic storms can induce currents in power lines, causing transformers to overheat and potentially leading to widespread power outages.
  • Satellite Communications: Charged particles can damage satellite electronics and disrupt communication signals.
  • GPS and Navigation Systems: Geomagnetic disturbances can interfere with the accuracy of GPS and other navigation systems.
  • Radio Communications: Storms can disrupt radio signals, affecting communication systems that rely on HF, VHF, and UHF bands.

Aurora formation

One of the most visually striking effects of geomagnetic storms is the formation of auroras, also known as the Northern and Southern Lights.

As charged particles collide with Earth’s upper atmosphere, they excite oxygen and nitrogen atoms, causing them to emit light in various colors.

Monitoring and forecasting

Scientists continuously monitor the Sun’s activity and use various instruments to detect and measure CMEs and solar flares.

This data helps them forecast the timing and intensity of geomagnetic storms, allowing for better preparedness and mitigation of potential impacts.

Historical geomagnetic storms

Some of the most notable geomagnetic storms in history include:

  • The Carrington Event (1859): The most powerful geomagnetic storm on record, which caused widespread telegraph system failures and auroras visible as far south as the Caribbean.
  • The Halloween Storms (2003): A series of powerful geomagnetic storms that caused power outages in Sweden and damaged transformers in South Africa.
  • The Quebec Blackout (1989): A geomagnetic storm that caused a massive power outage affecting millions of people in Quebec, Canada.

Understanding geomagnetic storms is crucial for protecting our technology-dependent world and mitigating the potential risks associated with these powerful space weather events.

Stay tuned to and the Space Weather Prediction Center (SWPC) for updates.


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