Solar activity reached high levels in 24 hours to 00:30 UTC on November 6 as Region 4274 (‘beta-gamma-delta’) produced two powerful M-class flares and associated Earth-directed CMEs.
This region continues to exhibit flux emergence within its intermediate region – increasing its spot count, length, and area, according to the Space Weather Prediction Center (SWPC). Sheering across its center retains its complex magnetic field and its resulting high flare count.
The first event, an M7.4 flare at 11:19 UTC on November 5, generated a 45-minute Tenflare radio burst peaking at 760 sfu and a full-halo CME. SWPC modeling shows a clear Earth-directed component expected to arrive late November 6 to early November 7. A component of CME produced by X1.8 solar flare on November 4 is expected to arrive around the same time.
The second, an M8.6 flare at 22:07 UTC, produced a Type II radio sweep with a measured shock velocity of 1 395 km/s from Palahua, Hawaii. Extensive coronal dimming was observed around the source region, suggesting another CME lift-off. Analysis of this event is still in progress.
The X1.1 flare at 22:01 UTC on November 4 originated from a region whose location is just beyond the east limb at S15. Satellite imagery at 21:00 UTC on November 5 showed a “not-so” complex region in that vicinity. “It could be the leader that has decayed or the region responsible is still out of view. Will hold off on numbering the region until a better view is obtainable,” SWPC noted.
Over the past 24 hours, solar wind parameters were disturbed due to a persistent period of southward Bz influenced by a slow-moving CME. Total field strength (Bt) was at 5-7 nT up until CME arrival at roughly 17:00 UTC on November 5. Bt increased to 14 nT with the north-south (Bz) component dropping to -14 nT as of 21:30 UTC.
Geomagnetic field responded with G1 – Minor storm levels at 20:16 UTC, increasing to G2 – Moderate at 22:53 UTC and to G3 – Strong by 05:36 UTC on November 6.
Solar wind parameters will remain enhanced due to the current CMEs, an incoming CIR with a HSS behind it, and two more CMEs on the way. The most significant disturbance is expected to be associated with the full halo M7.4. Calculated velocities between 1 100 to 1 400 km/s should put the CME arrival time right around the turn of the UTC day on 07 Nov. A sharp rise in density and IMF coupled with rapid rise in solar wind speeds is expected.
Under these conditions, SWPC expects geomagnetic activity to intensify to G3 – Strong levels as the Earth-directed halo CME arrives.
Additional flares from Region 4274 and emerging Region 4275 may further extend the period of strong geomagnetic activity through November 8. SWPC forecasters assign a 70% probability for M-class and 25% for X-class flares in the next two days.
G3 – Strong geomagnetic storming is capable of causing voltage fluctuations in power systems, surface charging and increased drag on low-Earth-orbit satellites, and intermittent HF radio and GPS degradation at high latitudes.
Aurora visibility could extend well into the northern United States and across Canada as the disturbance peaks between late November 6 and November 7 (UTC).
References:
1 Forecast Discussion – NOAA/SWPC – 00:30 UTC on November 6, 2025