When is the geomagnetic storm expected to hit Earth?

NOAA's Space Weather Prediction Center modeled the CME's leading edge arriving around 1 a.m. EDT (0500 GMT) on Oct. 9, 2026, with the storm watch covering that full day.

What caused this storm watch?

An M1.4-class solar flare erupted from sunspot region AR4549 on Oct. 6, 2026, launching a coronal mass ejection toward Earth at about 560 km/s, according to NOAA and SSBCrack News.

How strong will the storm be?

NOAA's Oct. 7 three-day forecast put the peak Kp index at 5.67 on Oct. 9, within the G2 (Moderate) range, after an earlier window at Kp 5.00, around the G1 (Minor) threshold; the agency's watch covers both G1 and G2 outcomes.

Is the forecast certain?

No. Space physicist Vincent Ledvina said it was still too early to know how much of the CME was Earth-directed, and NOAA's watch itself spans a range from Minor to Moderate storm conditions.

Space · News

NOAA Issues G1-G2 Geomagnetic Storm Watch for Oct. 9, Aurora Possible in US

Published: October 7, 2026 at 09:51 AM UTC

In brief

NOAA's Space Weather Prediction Center has issued a G1-to-G2 geomagnetic storm watch for Oct. 9, 2026, after a solar flare and coronal mass ejection left the sun on Oct. 6. Forecasters say the resulting storm could push the northern lights into northern-tier US states, with NOAA's own scale citing New York and Idaho as the historical southern edge for G2-level displays, though the storm's exact strength remains uncertain.

A flare triggers the watch

On Oct. 6, 2026, the sun produced an M1.4-class solar flare from sunspot region AR4549, located near the center of the Earth-facing solar disk, according to NOAA's Space Weather Prediction Center (SWPC). The eruption released a coronal mass ejection (CME), a burst of magnetized solar plasma, that SSBCrack News reported was traveling toward Earth at roughly 560 kilometers per second.

Hours after the first flare, the same active region produced a second flare, which Daily Galaxy described as M1.9-class and SSBCrack News described as M1.8-class. Both outlets reported that a neighboring region, AR4545, also showed increased activity.

Using SWPC's WSA-ENLIL solar-wind model, forecasters projected that the leading edge of the CME would reach Earth at around 1 a.m. EDT (0500 GMT) on Oct. 9, according to SSBCrack News.

NOAA's G1-G2 storm watch

SWPC issued a geomagnetic storm watch on Oct. 6 at 16:40 UTC, saying conditions on Oct. 9 could reach G1 (Minor) to G2 (Moderate) on NOAA's five-step geomagnetic storm scale, driven by the incoming CME. The agency added there was "a high chance for additional M-class flare activity" from AR4549 in the following days.

SWPC's three-day forecast, issued Oct. 7 at 00:30 UTC, put the Kp index — the standard 0-to-9 scale used to measure geomagnetic disturbance — at a peak of 5.67 in the three-hour window from 09:00 to 12:00 UTC on Oct. 9, within the G2 range. An earlier window that same day, 03:00 to 06:00 UTC, was forecast at Kp 5.00, at the threshold of G1 conditions.

How far south the aurora could reach

NOAA's space weather scale describes typical aurora visibility at each storm level based on past events, not a location-specific prediction for this particular CME. According to that scale, G1 storms commonly make the aurora visible over northern Michigan and Maine, while G2 storms have pushed visibility as far south as New York and Idaho, at roughly 55 degrees geomagnetic latitude.

NOAA geomagnetic storm scale: aurora visibility examples
Storm level	Associated Kp	Example southern limit (NOAA scale)
G1 (Minor)	Kp 5	Northern Michigan and Maine
G2 (Moderate)	Kp 6	New York and Idaho (about 55° geomagnetic latitude)

Because actual visibility depends on real-time storm strength, cloud cover and local light pollution, these are historical reference points rather than a guarantee for any single state on Oct. 9.

What forecasters say is still uncertain

Scientists said the storm's eventual strength was difficult to pin down before the CME arrived. "It is still too early to say how much of the CME has escaped the solar atmosphere and how much it is directed at Earth," Vincent Ledvina, a space physicist and aurora photographer, said, according to Daily Galaxy. SSBCrack News separately reported that Ledvina said additional data was needed to determine how much of the CME was directed at Earth.

SSBCrack News reported that people hoping to watch should keep camera batteries charged and monitor updated aurora alerts, since the CME's precise orientation and speed at arrival — not just its initial launch speed — determine how strong and how far south any resulting storm becomes.

Background: why this is being watched

SWPC tracks the sun's activity because CMEs and solar flares from active regions like AR4549 can disturb Earth's magnetic field for one to several days after launch. The agency's G-scale, from G1 to G5, is the US government's standard tool for communicating the expected severity of a geomagnetic storm to the public, utilities and satellite operators.

Questions

When is the geomagnetic storm expected to hit Earth?: NOAA's Space Weather Prediction Center modeled the CME's leading edge arriving around 1 a.m. EDT (0500 GMT) on Oct. 9, 2026, with the storm watch covering that full day.
What caused this storm watch?: An M1.4-class solar flare erupted from sunspot region AR4549 on Oct. 6, 2026, launching a coronal mass ejection toward Earth at about 560 km/s, according to NOAA and SSBCrack News.
How strong will the storm be?: NOAA's Oct. 7 three-day forecast put the peak Kp index at 5.67 on Oct. 9, within the G2 (Moderate) range, after an earlier window at Kp 5.00, around the G1 (Minor) threshold; the agency's watch covers both G1 and G2 outcomes.
Which states might see the northern lights?: NOAA's general storm scale lists northern Michigan and Maine as typical for G1 storms and New York and Idaho as the historical southern edge for G2 storms, though actual visibility on Oct. 9 depends on the storm's real-time strength.
Is the forecast certain?: No. Space physicist Vincent Ledvina said it was still too early to know how much of the CME was Earth-directed, and NOAA's watch itself spans a range from Minor to Moderate storm conditions.

Sources

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