
Sun news October 21:Fast wind arrives, and more to come
Today’s top story: The anticipated stream of fast solar wind from a coronal hole reached Earth today. However, it didn’t trigger the expected G1 (minor) geomagnetic storm. Instead, the wind only triggered active disturbance (Kp 4) in our magnetic field. But there’s another chance ahead. A second coronal hole now is now sitting near the center of the solar disk, facing Earth. Its fast solar wind may start reaching us in the coming days. That could disturb Earth’s magnetic field again and bring a fresh chance for auroral displays.
Past 24 hours on the sun
(11 UTC October 20 – 11 UTC October 21)
Flare activity: Solar activity stayed at low levels, but flare production dropped. Observers registered only 11 flares this period, compared to 22 yesterday. C-class output fell too, with just two C-class (common) flares and nine B-class (weak).
- Strongest flare: A C2.8 from AR4557, peaking at 13:56 UTC on October 20.
- Other notable flare: A C1.4 from AR4551, peaking at 18:36 UTC on October 20.
- Lead flare producer: AR4557 produced eight of the period’s 11 flares, including the strongest. Meanwhile, AR4551 contributed the other three.
Sunspot regions: Currently, only three numbered sunspot regions populate the visible disk. Notably, the eastern hemisphere has run out of numbered regions entirely.
- AR4551 (beta magnetic configuration): This large region is about to rotate to the far side, sitting right on the sun’s southwest shoulder. At that angle, its exact configuration is hard to determine. For now, it’s departing as a beta region with six sunspots, amid jets and prominences.
- AR4557 (beta-gamma): This region underwent minor decay and lost its delta. Even so, it still holds a beta-gamma configuration across 20 spots. And it took over as the period’s flare leader once again, firing eight flares, including the strongest, a C2.8.
- AR4560 (beta-gamma): This region kept growing, increasing in extent and developing additional sunspots. It now counts 21 spots, the most on the disk, and has gained a beta-gamma configuration. That makes it one to watch.
Blasts from the sun? Analysts identified several coronal mass ejections (CMEs) launched toward the north and northeast during this period. Initial analysis suggests none of these chunks of solar stuff are Earth-bound.
Past 24 hours in space weather
Solar wind: Solar wind speeds increased to moderate levels during this period. The arrival of a new high-speed stream drove the jump.
Bt, Bz and magnetic coupling: The total interplanetary magnetic field (Bt) stayed calm early in the period. Then, at around 12 UTC on October 20, it rose to moderate strength and held there through the time of this report. Meanwhile, the north-south component (Bz) pointed south for most of the period. Long, steady southward stretches like that favor auroral displays.
Earth’s magnetic field: The geomagnetic field ranged from quiet to active levels, with the Kp index at 2 to 4. Conditions reached the Kp 4 threshold at 4:29 UTC on October 21. At the time of this report, the Kp index sits at level 2.
What’s ahead? Sun–Earth forecast
Flare activity forecast: Forecasters expect low solar activity to continue, with a chance for isolated M-class flares. The chance for M-class flares stands at 25%. Meanwhile, a small 5% chance of X-class (strong) flares remains. With AR4551 departing to the far side today, AR4557 and the growing AR4560, both beta-gamma, are now the main drivers.
Geomagnetic activity forecast:
- October 21: Expect unsettled to active conditions, with Kp 4 likely as the high-speed stream continues in full. Auroras could appear at high latitudes, with a chance of glimpses from northern Scotland and southern New Zealand.
- October 22: Unsettled to active conditions (Kp 3-4) should continue as the coronal hole’s fast wind lingers through the day. Auroras will likely retreat to the highest latitudes.
- October 23: Anticipate a return to mostly quiet conditions as fast solar wind effects wane.


Sun news October 20: Fast solar wind approaching Earth
A stream of fast solar wind from a coronal hole — a cooler, less-dense region in the sun’s atmosphere — is expected to reach Earth today. When it does, forecasters expect it to trigger G1 (minor) geomagnetic storm conditions. So aurora-watchers at high latitudes, keep an eye on the sky tonight!
Past 24 hours on the sun
(11 UTC October 19 – 11 UTC October 20)
Flare activity: Solar activity returned to low levels. Observers recorded 22 flares in all: 12 C-class (common) and 10 B-class (weak).
- Strongest flare: A C3.5 from AR4557, peaking at 2:45 UTC on October 20.
- Other notable flares: AR4557 fired most of the period’s flares, with AR4551 and AR4560 adding a handful more.
- Lead flare producer: AR4557 produced 17 of the period’s 22 flares, including the strongest. Meanwhile, AR4551 contributed 3 flares, and AR4560 added 2.
Sunspot regions: Currently, only three numbered sunspot regions populate the visible disk.
- AR4551 (beta-gamma): This large, magnetically complex region started showing signs of decay. Now getting closer to the solar southwest.
- AR4557 (beta): This region lost its delta configuration, but it took over as the period’s flare leader. It fired 17 flares, including the strongest, a C3.5. Its evolving magnetic structure keeps it well worth watching.
- AR4560 (beta): This newcomer emerged on the northeast portion of the disk and kept developing. It produced 2 flares. For now, it remains small and magnetically simple.
Blasts from the sun? Analysts identified no Earth-directed coronal mass ejections (CMEs) during this period. They also confirmed that the CME from yesterday’s M1.7 (moderate) flare is not heading our way.
Past 24 hours in space weather
Solar wind: Solar wind speeds eased toward normal levels as a previous coronal hole’s influence waned. However, that should change soon, as a new high-speed stream is due to arrive today.
Bt, Bz and magnetic coupling: The total interplanetary magnetic field (Bt) stayed mostly calm, briefly reaching moderate levels earlier in the period. Meanwhile, the north-south component (Bz) varied but favored a northward orientation, with brief southward dips.
Earth’s magnetic field: The geomagnetic field stayed at very quiet levels, with the Kp index ranging from 0 to 1. Aurora stayed confined to the highest latitudes. At the time of this report the Kp index sits at level 1.

Sun news October 19: M flare erupts as solar wind heads to Earth
A coronal hole — an area of lower density in the sun’s atmosphere — is currently crossing the center of the solar disk. The high-speed solar wind streaming out of it should reach Earth tomorrow. When it arrives, forecasters expect G1 (minor) geomagnetic storm conditions and possible auroras at high latitudes. So what does that mean for skywatchers? If you live in the far north or south, keep an eye out for auroras late on October 19 or on October 20. Those in Northern Scotland and southern New Zealand could catch a glimpse. Meanwhile, AR4551 fired off an M1.7 (moderate) flare near the end of our reporting window, peaking at 9:03 UTC this morning. The blast caused an R1 (minor) radio blackout. This large, magnetically complex sunspot region has dominated flare production for days. And according to forecasters, it still has more to give. Stay tuned!
Past 24 hours on the sun
(11 UTC October 18 – 11 UTC October 19)
Flare activity: Solar activity reached moderate levels. Observers recorded 8 flares in all: 1 M-class, 5 C-class (common) and 2 B-class (weak).
- Strongest flare: An M1.7 from AR4551, peaking at 09:03 UTC on October 19. It produced an R1 (minor) radio blackout over southern Africa.
- Other notable flares: A C2.1 from AR4551 peaked at 19:17 UTC on October 18. Meanwhile, newly numbered AR4559 fired two C-class flares, including a C2.0 at 07:18 UTC on October 19.
- Lead flare producer: AR4551 produced 5 of the 8 flares, including the only M-class event. AR4559 contributed 2 C-class flares, and AR4557 added 1 B-class flare.
Sunspot regions: Four numbered sunspot regions populated the visible disk, including two newcomers: AR4559 and AR4560.
- AR4551 (beta-gamma): This large, magnetically complex region remains one of the biggest on the disk. Its strong, persistent, leader spot keeps it productive. In fact, it produced the bulk of the period’s flares, including the M1.7. Forecasters still consider it a potent source of more moderate flares.
- AR4557 (beta-delta): This region shrank slightly. However, it developed a weak delta configuration. It produced one B-class flare during the period. Despite some decay, its evolving magnetic structure keeps it worth watching.
- AR4560 (beta): This newcomer emerged on the northeast portion of the disk and kept developing. For now, it remains small and magnetically simple.
- AR4559 (beta): This newly numbered region emerged just south of AR4551. Despite being small and simple, this region surprised observers with two C-class flares.
Blasts from the sun? Analysts identified no Earth-directed coronal mass ejections (CMEs) during this period.
Past 24 hours in space weather
Solar wind: Solar wind speeds were slightly elevated as a previous coronal hole’s influence waned. By the end, conditions trended toward normal levels.
Bt, Bz and magnetic coupling: The total interplanetary magnetic field (Bt) stayed mostly calm. Earlier in the period, it briefly reached moderate levels. Meanwhile, the north-south component (Bz) varied but favored a northward orientation, with brief southward dips.
Earth’s magnetic field: The geomagnetic field stayed quiet to unsettled, with the Kp index ranging from 1 to 3. Conditions reached no storm thresholds. As a result, aurora stayed confined to the highest latitudes.

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Bottom line: Sun news October 21, 2026: Fast solar wind arrived but fell short of a G1 storm, peaking at Kp 4. A second coronal hole now faces Earth. More to come!
