X1.6 solar flare erupts from Region 3663, forecast calls for CME impact late May 5

A major solar flare measuring X1.6 erupted from Active Region 3663 (beta-delta) at 02:22 UTC on May 3, 2024. The event started at 02:11 and ended at 02:27 UTC. A G1 – Minor geomagnetic storm is in effect for May 5 and a G2 – Moderate for May 6 (UTC day) due to the potential arrival of a CME produced by this flare.

A Type II Radio Emission, with an estimated velocity of 959 km/s, was associated with the event, indicating a coronal mass ejection (CME) was produced.

A Type IV emission was detected at 02:33 UTC. Type IV emissions occur in association with major eruptions on the sun and are typically associated with strong coronal mass ejections and solar radiation storms.

Additionally, a 10 cm Radio Burst (tenflare) lasting 4 minutes and with a peak flux of 660 sfu was detected from 02:19 to 02:23 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. The 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 Australia, east Asia, and the Pacific Ocean at the time of the flare.

The associated CME, first visible in LASCO imagery off the NNE at 02:48 UTC, is expected to arrive late on May 5 or early May 6, SWPC forecasters said at 00:30 UTC on May 4.

Active conditions and periods of G1 – Minor storming are expected on May 5 due to continued positive polarity CH HSS influences in addition to the anticipated arrival of the May 3 CME late in the day. Periods of G1 – Minor to G2 Moderate storming are expected on May 6 due to continued CME activity and CH HSS influences.

Solar activity was at moderate levels in 24 hours to 00:30 UTC on May 3, due to flaring activity from regions 3663 and 3664, including M1.0 at 02:17 UTC and M2.7 at 20:57 UTC on May 2.

Solar wind parameters were slightly enhanced until 13:17 UTC on May 2 when a shock was observed at the ACE spacecraft indicating the arrival of a CME, possibly from April 29.

Total field increased to 19 nT while solar wind speed only increased to near 400 km/s. Solar wind speed further increased to around 450 km/s with total field remaining in the 17 to 20 nT range. Prolonged periods of southward Bz were observed reaching -19 nT.

CME impact on Earth was detected at around 14:12 UTC (29 nT at HAD magnetometer), resulting in G3 -Strong geomagnetic storm conditions.

According to Dr. Tamitha Skov, a noted space weather physicist, this activity was due to two stealth coronal mass ejections (CMEs) — the first impacting Earth on May 1 and the second on May 2.

“Both of these events have eluded detection by several (if not all of the big space weather forecasting agencies) so it is clear, stealthy solar storms continue to be a problem through solar maximum.”

Featured image: X1.6 solar flare on May 3, 2024. Credit: NASA/SDO AIA 304, Helioviewer, The Watchers