Sun news: Coronal hole winds set to spark auroras

Sun news October 4: Coronal hole winds set to spark auroras

Today’s top story: A coronal hole high-speed stream is arriving at Earth today. Forecasters expect it to push solar wind speeds to about 550 to 600 km/s (fast wind speeds), bringing G1 minor geomagnetic storm conditions. There is even a slight chance of G2 moderate storms. Aurora watchers in northern Scotland and similar latitudes could see displays from late October 4 through October 5. Meanwhile, the sun itself remains very quiet. Only B-class flares popped off over the past day. Four small, magnetically simple sunspot regions dot the visible disk. The weak interplanetary coronal mass ejection (CME) from September 28 did graze Earth on October 3. However, it produced only a minor blip in solar wind speed and no significant geomagnetic response. The coronal hole stream is the main act now. Stay tuned!

Past 24 hours on the sun

(11 UTC October 3 – 11 UTC October 4)

Flare activity: Very low. The sun produced 9 B-class flares. No C-class (common) or stronger events occurred.

• Strongest flare: B9.3, peaking at 6:30 UTC on October 4 from AR4546 (S19W61).
• Other notable flares: A B5.0 peaked at 15:07 UTC on October 3 from AR4545. A B4.9 peaked at 00:46 UTC on October 4, also from AR4545. AR4546 contributed three additional B-class flares late in the period.
• Lead flare producer: AR4545 generated 5 of the 9 flares. AR4546 produced the remaining 4, including the strongest.

Sunspot regions: Observers tracked 4 numbered regions on the disk, including 2 newcomers.

• AR4545 (beta): This region grew slightly during the period. It was the most active spot group, producing 5 B-class flares. Still, it managed nothing above B-class. Located in the northern hemisphere, it rotates slowly toward disk center.
• AR4546 (beta): Gained a single trailing spot. Despite being listed as quiet by forecasters early in the period, it became increasingly active later, producing 4 B-class flares, including the period’s strongest, a B9.3. It sits in the southern hemisphere, approaching the western limb.

Blasts from the sun? Analysts observed no Earth-directed coronal mass ejections (CMEs) in coronagraph imagery. A filament was observed lifting off between approximately 02/1845 UTC and 03/0345 UTC (October 2 to 3). However, most of the material appeared to be reabsorbed. Coronagraph imagery confirmed no associated CME.

Past 24 hours in space weather

Solar wind: Speeds were slow, hovering near 270 km/s at the start of the period. A minor enhancement arrived around 03/0118 UTC, pushing speeds to about 300 to 305 km/s. Density briefly jumped at the shock front. By 03/1300 UTC, speeds had dropped back to near 270 km/s and conditions returned to background levels.

Bt, Bz and magnetic coupling: The total interplanetary magnetic field (IMF) increased from about 4 nT to a peak of 9 nT during the minor enhancement, then settled back to around 4 nT. The Bz component dipped as far south as minus 6 nT briefly but was otherwise unremarkable.

Earth’s magnetic field: Geomagnetic conditions stayed at quiet to unsettled levels. The Kp index ranged from 0 to 3. No geomagnetic storming occurred.

What’s ahead? Sun–Earth forecast

Flare activity forecast: Forecasters expect very low activity to continue, with a chance of C-class flares through October 6. All four numbered regions are small and magnetically simple (beta or alpha). No M-class or X-class flares are expected.

Geomagnetic activity forecast:

• October 4: Active conditions expected, with G1 minor storm levels likely and a slight chance of G2 moderate storms. The driver is a coronal hole high-speed stream from a positive-polarity equatorial coronal hole. Aurora may be visible from northern Scotland, New Zealand’s South Island, and similar geomagnetic latitudes. Kp 5 likely, possibly reaching Kp 6.
• October 5: Unsettled to active conditions as coronal hole influence persists but begins to wane. Aurora chances diminish to higher latitudes only.
• October 6: Unsettled to active levels early, then easing to quiet to unsettled as the high-speed stream fades.
• October 7: Mainly quiet to unsettled conditions. No significant drivers expected.

Sun news October 3: Sun-stuff arrives, with more on the way

The anticipated coronal mass ejection (CME) — a moving blob of solar materials and magnetic fields — has arrived. But it brought only a mild disturbance to Earth’s magnetic field. No G1 (minor) geomagnetic storm registered. Still, the show might not be over yet. Forecasters consider G1 disturbances possible today, as a stream of fast solar wind arrives from a large coronal hole on the sun. So we might have auroral displays at high latitudes, especially now that aurora season is here. Then, tomorrow, October 4, a second blob of solar stuff should deliver a glancing blow. Combined with the fast solar wind, it might keep stirring space weather at Earth. So we’ll keep watching …

Do health effects from solar flares bother you? Watch this video

Past 24 hours on the sun

(11 UTC October 2 – 11 UTC October 3)

Flare activity: Solar activity dropped to very low levels over the past 24 hours. Observers registered only two faint B-class (weak) flares in total.

• Strongest flare: A B3.3 from active region AR4535 in the northwest, peaking at 17:37 UTC on October 2.
• Lead flare producer: With just two flares, AR4535 and AR4546 each produced one.

Sunspot regions: Currently, the solar disk as seen from Earth shows two numbered sunspot regions. One of them is a newcomer that emerged from nowhere in the southwest quadrant and received its number this period: AR4546. Meanwhile, AR4544, numbered earlier this week, no longer appears on the list.

• AR4535 (alpha): This region has now departed to the far side of our sun. Just two days ago it showed a beta-gamma configuration. Its simpler alpha label today likely reflects its position right at the limb, where foreshortening makes analysis difficult. Before leaving, it still produced one B flare during the period.
• AR4545 (beta): This is the northeast newcomer that produced faint B flares earlier this week, now with an official number. Today it stayed quiet.
• AR4546 (beta): This newcomer emerged in the southwest and received its official number. It produced one B flare during the period.

Blasts from the sun? Observers registered no Earth-bound CMEs during the period. A huge filament eruption on October 2 hurled plasma into space, but it occurred far from Earth’s direction, so that material won’t reach us.

Past 24 hours in space weather

Solar wind: Solar wind speeds averaged low levels, with slight peaks from the arriving CME. Meanwhile, a coronal hole high-speed stream from a large coronal hole is on its way. So conditions should change today and tomorrow, especially as a second CME delivers a glancing blow.

Bt, Bz and magnetic coupling: The total interplanetary magnetic field (IMF) stayed weak early in the period. Then, at 3 UTC this morning, it began climbing to moderate strength. Meanwhile, the north-south component (Bz) held a southward orientation for the entire period, with just a faint northward peak early on. The strongest peaks pointed south. At the time of this writing, it remains strongly southward.

Earth’s magnetic field: Geomagnetic activity rose from quiet to unsettled levels during this period. The Kp index ranged from 0 to 3. At the time of this report, it sits at level 3.

Sun news October 2: Two bursts of sun-stuff heading to Earth

Two blobs of solar stuff — or coronal mass ejections (CMEs) — are heading our way at Earth. The first is expected to arrive later today, likely disturbing Earth’s magnetic field up to G1 (minor) geomagnetic levels. That could trigger auroral displays at high latitudes, especially now we’re in an aurora season. And the show may be extended through the weekend. Tomorrow, a stream of fast solar wind coming from a large coronal hole might continue stirring space weather at Earth. And adding to all this, a second CME might deliver a weak glancing blow to us on October 4. Good luck and clear skies, aurora chasers!

Past 24 hours on the sun

(11 UTC October 1 – 11 UTC October 2)

Flare activity: Solar activity increased from very low to low levels over the past 24 hours. Observers registered five flares in total: a C-class (common) event and four B-class (weak) flares.

• Strongest flare: A C1.5 flare by active region AR4545 in the northeast. It peaked at 21:37 UTC on October 1.
• Lead flare producer:  Active region AR4535 reached the top position, producing three flares during this period. The sparks were three B-class (weak) flares.

Sunspot regions: Today the sun continued showing two numbered sunspot regions, but one is a newcomer in the northeast that’s been producing C and B flares. Finally it received an official number: AR4545.

• AR4535 (alpha magnetic complexity): This region is now at the very edge of the northwest solar horizon and is soon to depart to the far side of our star. This position makes it difficult to analyze, but it appears to have lost its gamma complexity and now shows a simple alpha setup. But it produced three B flares before departing.
• AR4544: This region decayed to only plage and remained inactive.
• AR4545 (beta): This active region that has been blasting flares the whole week finally got numbered and produced today’s only C flare.

Blasts from the sun? The arrival of two coronal mass ejections (CMEs) is anticipated over the next few days. Other than that, no Earth-bound CMEs were registered during the period.

Past 24 hours in space weather

Solar wind: Solar wind speeds averaged low, at background levels. A coronal hole high-speed stream from a large coronal hole is on its way. Space weather conditions are expected to change in the next couple of days.

Bt, Bz and magnetic coupling: The total interplanetary magnetic field (IMF) stayed weak during the period. Meanwhile, the north-south component (Bz) kept shifting from northward to southward for the entire period. The strongest peaks were northward.

Earth’s magnetic field: Geomagnetic activity increased to quiet levels during this period, starting to show some action. The Kp index ranged from 0 to 2. At the time of this report, it sits at level 2.

Sun news October 1: Heart-shaped coronal hole facing Earth?

Today’s sun brings something of a Rorschach test. What does that central coronal hole look like to you? Some members of our team see a heart … and others see a devilish face! Whatever it looks like, it’s sending fast solar wind straight at Earth. This should disturb our magnetic field from Saturday. And that’s not all. First, a chunk of solar stuff — or coronal mass ejection (CME) — from the September 28 eruption should reach us tomorrow. Then a CME from yesterday’s C8.6 flare may deliver a weak glancing blow on October 4. All together, these could create promising conditions for auroras over the next few nights. So keep watching the sky, especially at high latitudes.

Past 24 hours on the sun

(11 UTC September 30 – 11 UTC October 1)

Flare activity: Solar activity dropped even lower, to very low levels, during the past 24 hours. Observers registered just one flare: a B-class (weak) event.

• Strongest flare: The period’s only flare, a B5.0, came from an incoming, as-yet-unnumbered region in the northeast. It peaked at 2:50 UTC on October 1.
• Lead flare producer: With only one flare, there was only one producer: that unnumbered newcomer in the northeast quadrant.

Sunspot regions: Today the sun continued showing two numbered sunspot regions. Meanwhile, the northeast region producing B flares hasn’t received an official number yet.

• AR4535 (beta-gamma magnetic complexity): Yesterday, this region produced an almost M-class flare. During this period, however, it produced no flares.
• AR4544 (beta): This region showed growth. Still, it stayed inactive.

Blasts from the sun? Specialists have confirmed the CME that AR4535 hurled into space during the C8.6 event. They anticipate a weak glancing blow at Earth, with arrival expected on October 4.

Past 24 hours in space weather

Solar wind: Solar wind speeds stayed low, at background levels, as the previous coronal hole high-speed stream waned. However, a large new coronal hole now sits at the center of the Earth-facing disk. Its fast solar wind may start reaching us in a couple of days.

Bt, Bz and magnetic coupling: The total interplanetary magnetic field stayed weak during the period. At the time of this writing, though, it peaked at moderate levels. Meanwhile, the north-south component (Bz) pointed mostly northward for the entire period, with only a couple of very faint southward peaks.

Earth’s magnetic field: Geomagnetic activity stayed at very quiet levels during this period. The Kp index again ranged from 0 to 1. At the time of this report, it sits slightly above level 0.

Sun news September 30: Near-M flare! Sun waking up?

Our star surprised us again over the past day. This time the sun’s activity lull was broken by a near-M flare from sunspot region AR4535. The blast, a fiery C8.6, peaked at 2:46 UTC on September 30. We can clearly see a huge chunk of solar stuff was sent to space by this eruption. Modeling and analysis is underway to see if this blast could be heading to Earth. We have been observing this sunspot region, AR4535, since it developed a gamma magnetic complexity, and it’s now showing an even-more-promising beta-gamma configuration. A spark like this is what we have all have been expecting from this region. Is this AR4535 — and the sun — waking up?

Past 24 hours on the sun

(11 UTC September 29 – 11 UTC September 30)

Flare activity: Solar activity continued at low levels during the past 24 hours, but the near-M flare increased flare activity almost to moderate levels. We have not seen an actual M flare since September 5. Observers registered 5 flares in total: 3 C-class (common) and 2 B-class (weak).

• Strongest flare: A C8.6 from AR4535, peaking at 2:46 UTC on September 30.
• Lead flare producer: There is a newcomer in the northeast that dominated, firing three of the five flares: two Cs and one B flare.

Sunspot regions: Today our sun shows two numbered sunspot regions. A newcomer in the southwest received its official number during this period: AR4544. But the sunspot region producing C and B flares in the northeast hasn’t received an official number yet.

• AR4535 (beta-gamma magnetic complexity): This region surprised with an almost-M flare during the period.
• AR4544 (beta): Newcomer numbered during this period. Remained inactive.

Blasts from the sun? All eyes concentrated on the C8.6 flare by AR4535 this morning. An imminent coronal mass ejection (CME) may be confirmed. For now specialists are running modeling and analysis to determine if there is an Earth-directed component from this event.

Past 24 hours in space weather

Solar wind: Solar wind speeds held at low at background levels as the coronal hole high-speed stream waned.

Bt, Bz and magnetic coupling: The total interplanetary magnetic field stayed weak but we saw some moderate peaks during the period. Meanwhile, once again, the north-south component (Bz) pointed mostly southward for the entire period.

Earth’s magnetic field: Geomagnetic activity continued at very quiet levels during this period. Kp index ranged from 0 to 1. At the time of this report, the Kp index sits at level 1.

Sun news September 29: Huge eruption sends blob to Earth!

Yesterday, amid a period of solar calm, the sun took us by surprise. A huge eruption blasted from a filament in the northwest. The filament began lifting plasma at around 13 UTC and ended in a powerful eruption. That fiery blast hurled plasma into space as a chunk of solar stuff, known as a coronal mass ejection (CME). Early analysis suggests part of it may head straight for Earth, with arrival estimated by October 2. If it does, it could disturb Earth’s magnetic field up to G1 (minor) geomagnetic storm levels. That could trigger auroras at northerly latitudes.

Past 24 hours on the sun

(11 UTC September 28 – 11 UTC September 29)

Flare activity: Solar activity stayed low during the past 24 hours. Observers recorded 8 faint flares in total: 3 C-class (common) and 5 B-class (weak).

• Strongest flare: A C2.5 from AR4536, peaking at 15:19 UTC on September 28.
• Lead flare producer: AR4536 dominated, firing seven of the eight flares: 3 Cs and 4 Bs. In fact, it would have produced every flare of the period, if not for a single faint B flare from an as-yet-unnumbered newcomer.

Sunspot regions: Currently, the solar disk as seen from Earth shows only one numbered sunspot region, now that AR4536 has departed. Meanwhile, a newcomer in the northeast produced a B flare this morning. It hasn’t received an official number yet.

• AR4535 (beta-gamma): This region grew during the period and developed a gamma magnetic complexity. Even so, it produced no flares.
• AR4536 (beta): This region produced nearly every flare of the period. However, by the time of this writing, the sun’s rotation has carried it out of view over the west limb.

Blasts from the sun? The filament eruption described above produced a CME. Initial analysis suggests it carries an Earth-directed component. It could arrive on October 2 and bring conditions for a G1 (minor) geomagnetic storm. Further modeling and analysis continue.

Past 24 hours in space weather

Solar wind: Solar wind speeds held at low, background levels as the coronal hole high-speed stream waned.

Bt, Bz and magnetic coupling: The total interplanetary magnetic field (Bt) stayed weak. Meanwhile, the north-south component (Bz) pointed mostly southward for the entire period, with only a couple of weak northward peaks. At the time of this writing, it still points south.

Earth’s magnetic field: Geomagnetic activity stayed quiet (Kp 0 to 2) during the period. At the time of this report, the Kp index sits slightly above level 0.

Sun news September 28: Fast solar wind fades, quiet sun returns

The sun is taking a breather. Solar activity dropped to low levels over the past 24 hours, with only small C-class (common) flares popping off from a handful of modest sunspot regions. And conditions are quiet around Earth too, with fast solar wind from a coronal hole finally ceasing to disturb our planet’s magnetic field. Forecasters expect this tranquil stretch to continue for the next few days.

Past 24 hours on the sun

(11 UTC September 27 – 11 UTC September 28)

Flare activity: Solar activity stayed low. Observers recorded several small C-class flares during the period.

• Strongest flares: We saw only C1-level flares, from AR4534, AR4535 and AR4536.
• Lead flare producer: AR4535 and AR4536 shared the low-level flaring. AR4534, sitting at the west limb, also contributed as it rotated out of view.

Sunspot regions: SWPC lists three numbered active regions. The SIDC counts five groups on the disk, though some are decaying or about to rotate off the west limb.

• AR4534: This region fired the strongest recent flare, a C3.1. However, it now sits at or behind the west limb. So its Earth-facing influence is effectively over.
• AR4535 (beta): This is the most notable region left near the center of the disk. Forecasters noted additional spot development during the period. Still, its simple beta configuration limits its flare potential.
• AR4536 (beta): This region is approaching the west limb. It produced small C-class flares but will soon rotate out of view.

Blasts from the sun? Analysts detected no Earth-directed coronal mass ejections (CMEs) in available coronagraph imagery.

Past 24 hours in space weather

Solar wind: Solar wind speeds gradually decreased to background conditions as the coronal hole high-speed stream waned.

Bt, Bz and magnetic coupling: The total interplanetary magnetic field (Bt) stayed weak. Meanwhile, the north-south component (Bz) fluctuated between northward and southward.

Earth’s magnetic field: Geomagnetic activity reached unsettled to active levels (Kp 3 to 4) early on, driven by the tail end of the coronal hole stream. Conditions then calmed to mostly quiet (Kp 0 to 2). No geomagnetic storms occurred.

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Bottom line: Sun news October 3, 2026: A blob of solar stuff did arrive but brought mild disturbances. A second blob is anticipated to arrive tomorrow October 4.

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