United States

'Severe' G4 Geomagnetic Storm Expected To Generate Northern Lights Display Across The US

An intense geomagnetic storm, spurred by recent solar eruptions, promises a spectacular display of Northern Lights across the United States. Anticipation builds as experts forecast rare sightings as far south as Alabama and Northern California.

Northern Lights Across Northern US Photo: NOAA

xA severe geomagnetic storm is currently underway following eruptions from the Sun that propelled plasma towards Earth, potentially leading to the appearance of northern lights as far south as Alabama and Northern California by Monday.

NOAA's Space Weather Prediction Center (SWPC) issued a Geomagnetic Storm Alert on Sunday after Sun-observing satellites detected an X 1.1 solar flare followed by a coronal hole high-speed stream (CH HSS).

Auroras occur when charged particles from the Sun interact with the Earth’s atmosphere, resulting in the phenomenon known as the Northern and Southern Lights.

Initially predicted to rank between G1 and G2 on the SWPC's five-point scale of geomagnetic storms, experts now anticipate an increase to G3 by Monday. However, severe G4 space weather conditions have been observed within the past 24 hours and are forecasted to persist, according to the SWPC dashboard.

 A geomagnetic storm of a solar flare from the Sun on March 23, 2024
A geomagnetic storm of a solar flare from the Sun on March 23, 2024 Photo: NASA

A geomagnetic storm with a G1 rating is considered the weakest and typically results in Northern Lights displays over Alaska and Canada.

A G3 rating could potentially extend the visibility of auroras as far south as Washington, Wisconsin, and New York if the skies are clear.

With G4 conditions (level 4 out of 5) observed and forecasted to continue through Monday, Northern Lights displays may be visible as far south as Alabama and northern California.

Ground-based magnetometers also monitor the level of geomagnetic activity, and the event is quantified using the Kp index scale, which ranges from 0 to 9.

During a G3 event with a high Kp-index value in December, the northern lights were observed as far south as Las Vegas.

Space experts anticipate that the upcoming event could achieve a Kp-index value of at least 6, potentially making cities such as Seattle, Minneapolis, Green Bay, and Syracuse, New York, within the visibility zone.

The University of Alaska Fairbanks Geophysical Institute forecasts high aurora activity with Kp-6 levels continuing through Monday night.

Kp index value needed to see the Northern Lights in the US
Kp index value needed to see the Northern Lights in the US Photo: NOAA

“The public should not anticipate adverse impacts, and no action is necessary, but they should stay properly informed of storm progression by visiting our webpage,” stated the SWPC on Sunday.

The FOX Forecast Center predicts that there will likely be numerous sky hindrances on Sunday and Monday nights, potentially complicating viewing opportunities.

A large storm system is set to traverse the heartland of the country, generating abundant showers and thunderstorms.

Furthermore, the March full Worm Moon will illuminate the sky, resulting in reduced visibility of other celestial objects due to increased cloud cover.

A subtle lunar eclipse is scheduled to commence shortly before 1 a.m. EDT on Monday and extend until approximately 5:30 a.m. as the Moon traverses through Earth’s shadow.

Space experts acknowledge the difficulty in accurately determining the precise strength of geomagnetic activity, even with more frequent events.

Geomagnetic storms have increased in frequency over the past year as the Sun approaches the peak phase of its solar cycle.

A solar cycle refers to the recurring sequence of the Sun's magnetic field, which occurs approximately every 11 years and involves a reversal of the field polarity. Solar Cycle 25 commenced in 2019 and is projected to persist until 2030.