Major X2.8 solar flare erupts from old Region 3664 — now returning into Earth view

A major solar flare measuring X2.8 erupted from the Sun’s southeast limb at 07:08 UTC on May 27, 2024, producing a strong coronal mass ejection (CME). The event started at 06:49 and ended at 07:25 UTC.

• A fast, halo CME was produced. While a strong Earth-directed component is not expected, shock influences can not be ruled out.
• This solar flare was produced by old Active Region 3664.
• The region produced an X8.7 solar flare on May 14, the strongest in Solar Cycle 25, and multiple Earth-directed CMEs in the first two weeks of May, resulting in G5 – Extreme geomagnetic storming — the strongest since 2003.

A Type II Radio Emission, with an estimated velocity of 1 135 km/s, was detected starting at 06:59 UTC — suggesting a CME was produced.

A Type IV Radio Emission was detected at 07:05 UTC. Type IV emissions occur in association with major eruptions on the Sun and are typically associated with strong CMEs and solar radiation storms.

Additionally, a 10 cm Radio Burst (tenflare), lasting 9 minutes and with a peak flux of 300 sfu, was registered from 06:56 to 07:05 UTC. A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications.

Radio frequencies were forecast to be most degraded over eastern Africa, parts of eastern Europe, Asia and the Indian Ocean at the time of the flare.

This region — previously numbered 3664 — produced around 100 M-class and over 10 X-class solar flares during its last rotation through the Earth side of the Sun in the first half of May. Multiple CMEs it produced at the time resulted in a G5 – Extreme geomagnetic storm — the strongest since 2003 — on May 10 and 11. On May 14, this region produced X8.7 solar flare — currently the strongest solar flare of Solar Cycle 25.

The location of this region currently does not favor Earth-directed CMEs but this will change in the days ahead as it rotates toward the center of the disk.

A fast, halo CME, first seen in SOHO C2 imagery at approximately 07:12 UTC on May 27 was associated with this flare.

“A strong Earth-directed component is not expected. However, shock influences reaching Earth can not be ruled out,” SWPC forecasters said at 00:30 UTC on May 28.

Indirect shock arrival may arrive by late May 29. As a result, isolated active geomagnetic field levels, with a chance for G1 – Minor geomagnetic storming periods are expected. Quiet to unsettled conditions are expected on May 30 as any lingering shock effects wane.

References:

¹ Forecast Discussion – Issued: 2024 May 28 0030 UTC – Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center

Featured image credit: X2.8 solar flare on May 27, 2024. Credit: NASA SDO/AIA 304, Helioviewer, The Watchers