Sun news: Last night’s auroras

Sun news August 18: Last night’s auroras

Today’s top story: The blast of sun-stuff we were waiting for is here! It arrived at Earth and sparked a G1 (minor) geomagnetic storm overnight last night. The chunk of solar stuff – known to scientists as a coronal mass ejection (CME) – left the sun on August 14. Forecasters had expected it by late on August 17, so it ran a little late. But it got here! And it brought conditions for auroral displays. We have already received sighting reports from Alaska and Canada. The Kp 5 storm lasted for one three-hour synoptic period. Disturbances have reached most of the northern tier of the United States, from Washington State across Montana and North Dakota to northern Michigan and Maine.

Past 24 hours on the sun

(11 UTC August 17 – 11 UTC August 18)

Flare activity: Solar activity continued at low levels, with only C (common) flares over the past day, 8 flares in all.

• The strongest flare was a C4.0 from sunspot region AR4507 peaking at 6:43 UTC on August 18.
• Lead flare producer: AR4510 in the northwest fired 4 flares. AR4507 followed closely with 3 C flares. Meanwhile, AR4506 produced one.

Sunspot regions: Currently, the Earth-facing solar disk shows 4 numbered sunspot regions. Notably, 2 continue to show interesting magnetic configurations that could produce moderate flares, or even X (strong) flares.

• AR4506 (beta-gamma): This region kept its gamma. As a result, it maintains potential for further C and even M (moderate) flares. But it’s now getting closer to the sun’s west horizon as viewed from Earth. It produced only one C flare during the past day.
• AR4507 (beta-gamma-delta): This region produced the strongest flare of the past day. It also continued its rapid growth in the past day, developing a delta complexity. Consequently, it now has potential for stronger flares, including M and even X flares. It ranks as the largest sunspot region in extent on the side of the sun’s disk we see from Earth.
• AR4508 (beta): This region stayed stable and produced no flares.
• AR4510 (beta): This region is getting close to the western limb. Even so, it remained quite active during the period, topping the flare producer list.

Blasts from the sun? Three coronal mass ejection (CME) stories are ongoing:

• CME from August 14 (arrived): It got here early on August 18. So far, it has brought a G1 (minor) geomagnetic storming.
• CME from August 16 (analyzed): This CME erupted at approximately 19:48 UTC on August 16, alongside the C8.2 flare from AR4506. After modeling and analysis, specialists determined this chunk of solar stuff is not heading toward Earth.
• CME from August 17 (under analysis): Observers spotted a narrow CME at 18:45 UTC on August 17 near the northwest horizon. Initial analysis suggests the blast is not coming our way. But modeling continues.

Past 24 hours in space weather

Solar wind: Solar wind speeds increased to moderate levels starting at 21 UTC on August 17. They have held there through the time of this report.

Bt, Bz and magnetic coupling: The interplanetary magnetic field increased to strong levels. It then eased to moderate strength by 6 UTC this morning. Meanwhile, the Bz component pointed southward during most of the period. That southward orientation opened the door for the auroras. At around 4:30 UTC this morning, though, it shifted northward.

Earth’s magnetic field: Earth’s magnetic field stayed quiet-to-unsettled through much of the past day. It then reached active and storm levels, with Kp values ranging from 2 to 5. G1 (minor) geomagnetic storm conditions occurred, with Kp reaching 5 at 5:05 UTC this morning, August 18. At the time of this writing, the Kp index sits at level 4.

What’s ahead? Sun–Earth forecast

Flare activity forecast: Forecasters expect an increase in solar activity to low-to-moderate levels. The chance of M flares rose from 20% yesterday to 40% today. Likewise, the chance of an X flare rose to 10% today. AR4507 drives this jump, thanks to its new delta configuration. Meanwhile, AR4506 with its beta-gamma remains another likely source.

Geomagnetic activity forecast:

• August 18: Unsettled-to-active conditions may continue for the rest of the day. The August 14 CME has arrived, and a G1 (minor) storm is ongoing at the time of this writing. More G1 periods remain possible. Auroras may appear over Seattle, Edinburgh, the Scottish Highlands and similar latitudes. Clear skies to you, aurora watchers!
• August 19: Active conditions may continue as CME influence combines with a coronal hole high-speed stream. Together, these could compound the effects. G1 (minor) storm intervals are likely. Auroras may remain visible across northern Scotland, southern Alaska and similar latitudes.
• August 20: Geomagnetic activity should gradually decrease to mostly quiet levels as CME effects wane. Even so, the coronal hole high-speed stream may sustain unsettled to active intervals, with a slight chance of G1 (minor) storms. Aurora visibility will retreat to higher latitudes: northern Canada, Iceland and northern Scandinavia.

Sun news August 17: Sun-stuff blast headed to Earth

Earth is bracing for a one-two punch of solar weather over the coming days. Firstly, the great rope of solar material we mentioned yesterday – a coronal mass ejection (CME) that left the sun on August 14 – should sweep past our planet later today or early tomorrow. What does that mean for us? Forecasters expect G1 (minor) to G2 (moderate) geomagnetic storms on arrival. That could bring auroras to Alaska, much of Canada, and the northern tier of the United States, from Washington state across Montana and North Dakota to northern Michigan and Maine. Across the Atlantic, Scotland and northern England may catch a show as well. And a second punch may follow. The sun launched another burst of sun-stuff with yesterday’s strongest flare, a C8.2 from AR4506. Initial analysis points to an arrival at Earth around August 20, though with only modest effects.

Past 24 hours on the sun

(11 UTC August 16 – 11 UTC August 17)

Flare activity: Solar activity remained at low levels. Observers recorded 15 C-class flares. No M-class or X-class events occurred during the period.

• Strongest flare: A C8.2 from active region AR4506 peaking at 19:01 UTC on August 16. It fell just shy of the M-class threshold. Even so, this vigorous event produced an associated CME that’s now under analysis.
• Lead flare producer: AR4506 fired 7 of the 15 flares, including the C8.2 plus several others ranging from C1.5 to C2.1.
• Other notable flares: AR4507 contributed 6 flares (C1.0 to C2.3). Its strongest was a C2.3 at 2:13 UTC on August 17.

Sunspot regions: The Earth-facing solar disk displayed five numbered sunspot regions. Notably, two now show complex magnetic configurations that can produce moderate flares.

• AR4506 (beta-gamma): The period’s most prolific flare producer. This region now sits west of the center disk. It recently developed new intermediate spots. As a result, it maintains potential for further C-class and possibly M-class flaring as it approaches the western horizon.
• AR4507 (beta-gamma): The second most active region, producing frequent low-level C-class flares. The UK Met Office noted this region grew fairly rapidly over the past 24 hours.
• AR4508 (beta): This region produced minor C-class flaring. Otherwise, it stayed stable.
• AR4510 and the remaining numbered regions stayed generally simple and stable, or in gradual decay. However, AR4510 did produce a C2.0 flare late in the period.

Blasts from the sun? Two coronal mass ejection (CME) stories are ongoing, one imminent and one developing.

• CME from August 14 (imminent arrival): The CME that departed the sun on August 14 should arrive at Earth later on August 17 or during August 18, according to NOAA SWPC and UK Met Office forecasts. Forecasters assess G1 (minor) to G2 (moderate) geomagnetic storm conditions as likely upon arrival.
• CME from August 16 (under analysis): A CME erupted at approximately 19:48 UTC on August 16, alongside the C8.2 flare from AR4506. One model run predicts Earth arrival around 12:00 UTC on August 20. Kp estimates reach 3 to 4, depending on CME orientation.
• NOAA notes the C8.2-associated CME is still under analysis for a potential Earth-directed component. Additional imagery may refine these predictions.

Past 24 hours in space weather

Solar wind: Solar wind conditions were slightly below the normal background level.

Bt, Bz and magnetic coupling: The interplanetary magnetic field (IMF) total strength held at low levels. Meanwhile, the Bz component was weakly variable, with no sustained southward turns.

Earth’s magnetic field: Earth’s magnetic field stayed quiet throughout the period, with Kp values ranging from 0 to 2. No geomagnetic storms occurred.

Sun news August 16: ‘Rope’ of sun stuff en route to Earth

A rope of solar material and magnetic fields is on its way to Earth! It left the sun on August 14, when an arching filament lifted off and hurled plasma into space. Models now show this coronal mass ejection (CME) bearing down on our planet. Forecasters expect it to arrive late on August 17. When it hits, it should spark G1 (minor) geomagnetic storms, with a chance of G2 (moderate) levels if its magnetic field turns southward on arrival. In North America, that could bring auroras to Alaska, much of Canada, and the northern tier of the United States, from Washington state across Montana and North Dakota to northern Michigan and Maine. Across the Atlantic, Scotland, northern England, and Northern Ireland might catch a show on August 17. Down south, southern New Zealand and Tasmania could see displays too. Keep in mind, though, that forecasting centers disagree on the timing. Some models point to late on August 17, while others estimate a glancing blow as late as August 19.

Past 24 hours on the sun

(11 UTC August 15 – 11 UTC August 16)

Flare activity: Solar activity remained at low to moderate levels. Observers recorded 14 C-class flares and several B-class events. No M-class or X-class flares occurred over the past day.

• The strongest flare was a C3.7 from sunspot region AR4507 at 3:31 UTC on August 16. As a C-class event, it produced no radio blackout.
• Other notable flares: NOAA logged a C3.3 from AR4508 at 8:18 UTC on August 15 as the strongest event of the earlier portion of our reporting period (11 UTC August 15 – 11 UTC August 16). There was also a C3.2 from AR4507 at 14:38 UTC on August 15, a C2.7 from AR4506 at 02:42 UTC on August 16, and a C2.3 from AR4506 at 04:37 UTC on August 16.
• Lead flare producer: Sunspot region AR4507 topped the list, firing at least 10 events (both C- and B-class), including the period’s strongest flare. Meanwhile, AR4506 contributed six C-class flares in a concentrated burst between roughly 1 and 7 UTC on August 16.

Sunspot regions: The Earth-facing solar disk displayed at least six numbered active regions. Several exhibited notable growth.

• AR4507 (with a beta magnetic configuration) was the period’s most prolific flare producer. It grew and developed new intermediate spots, with some polarity mixing, as the UK Met Office noted. This evolution bears watching for potential increases in flare productivity.
• AR4506 (beta): This region also showed growth. Moreover, it produced that notable burst of C-class flaring overnight. As it nears the western limb, foreshortening is making assessment more difficult.
• AR4508 (beta): This region produced the C3.3 flare at 08:18 UTC on August 15, the strongest event of the first half of the period.
• AR4512 (beta): This region received its number during the period. It showed growth, so forecasters will monitor it for further development.
• The remaining numbered active regions stayed mostly stable or in gradual decay. Notably, no complex magnetic configurations, beta-gamma or delta, appeared anywhere on the disk.

Blasts from the sun? Observers spotted no new Earth-directed CMEs during the period. They cataloged two CMEs from August 15: one at 11:36 UTC (402 km/s) and another at 13:48 UTC (253 km/s). But neither should impact Earth. The SIDC also identified far-sided CMEs on August 14 (CMEs 708 and 709) that pose no threat. Instead, the key CME for the forecast remains the one launched on August 14 and now heading toward Earth.

Past 24 hours in space weather

Solar wind: Solar wind conditions reflected a typical slow-wind regime throughout the period. Speeds stayed low, ranging between approximately 330 and 380 km/s.

Bt, Bz and magnetic coupling: The IMF total strength stayed under 5 nT (low) according to NOAA. Meanwhile, the Bz component was weakly variable, fluctuating between approximately -6 and +4 nT. It never held a sustained southward orientation. As a result, conditions did not favor significant aurora production.

Earth’s magnetic field: Earth’s magnetic field ranged from quiet to unsettled levels over the past 24 hours. The Kp index ranged from 0+ to 2+ globally. Conditions crossed no G-scale geomagnetic storm thresholds.

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Bottom line: Sun news August 18, 2026: The awaited coronal mass ejection arrived and sparked a G1 (minor) storm. Observers spotted auroras in Alaska and Canada. The northern U.S. was also in range.

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