Sun news: Minor geomagnetic storm last night

Sun news July 23: Minor geomagnetic storm last night

(11 UTC to 11 UTC)

Today’s top story: Auroras were visible at northern latitudes last night, as far south as Maine and Michigan, as a stream of high-speed solar wind triggered a G1 (minor) geomagnetic storm. The disturbance was amplified by a corotating interaction region, which indicates turbulent knots of fast and slow solar wind streams mixing together. Minor-to-moderate storms are expected to continue through today, so there’s a chance for more auroras tonight!

• Flare activity on the sun itself is low with only C-class (common) flares in the last 24 hours. There were 12 C flares in total and the strongest event was a C6.4 flare produced at 20:11 UTC  on July 22. The blast was produced by active region AR4150 in the southeast. Active region AR4143 was the most flare productive with five C flares.
• There are seven sunspot regions on the Earth-facing disk. Active region AR4149 remains the largest and still has a beta-gamma magnetic complexity but remained flare unproductive during the period.  The remaining active regions on the solar disk have stable alpha or beta configurations. There is a new numbered sunspot region: AR4153 in the southeast.
• Blasts from the sun?  No Earth-oriented coronal mass ejections (CMEs) were observed in available coronagraph imagery.
• Solar wind speed increased from 346 km/s reaching a peak of 700 km/s ending the period around 650 km/s. The interplanetary magnetic field (IMF) is at a moderate level. The Bz intermittently moved south to north. At the time of this writing it is southward. A Bz south oriented favors auroral displays.
• Earth’s magnetic field was at quiet to storming levels (Kp = 1 – 5). A G1 (minor) geomagnetic storm was observed late yesterday. The Kp = 5 threshold was reached at 18 UTC on July 22 and stayed there for a two of three – hour synoptic periods. This was due to the arrival of a coronal hole high-speed stream CH HSS. As of this writing, the Kp index is 4 or active.

What’s ahead? Sun-Earth forecast

• Moderate-to-low flare activity is expected in the coming day. The chance for M (moderate) flares is 35% today, and the chance for X (strong) flares is 5% today.
• Geomagnetic activity forecast: Active levels may continue during the day today. G1 – G2 (minor – moderate) geomagnetic storm levels are likely. This was caused by a corotating interaction region (CIR) and a coronal hole high-speed stream (CH HSS). By July 24 all these effects may start to wane bringing conditions down to unsettled levels (Kp =3). Keep your eyes peeled for the northern lights!

Sun news July 22: Auroras coming

(11 UTC to 11 UTC)

A stream of fast solar wind from a recurrent coronal hole is expected to arrive late today or early tomorrow (July 23, in the early hours UTC). This high-speed stream could trigger G1 (minor) geomagnetic storm conditions, especially during the initial impact. That means auroras might be visible at high latitudes tomorrow morning in Scandinavia, and possibly tomorrow evening for northern North America.

• Flare activity is low. We saw only C-class (common) flares over the past day, seven C flares in total. The strongest events were a couple of C2.8 flares produced during our observation period. The first C2.8 from AR4139 in the northwest at 21:09 UTC on July 21. The second C2.8 flare was produced by AR4143 at 8:08 UTC on July 22.
• There are currently six sunspot regions on the Earth-facing disk. Active region AR4149 shows a beta-gamma magnetic complexity and is for now the largest sunspot region with potential for moderate activity. Meanwhile the rest of the active regions on the solar disk as we see it from Earth remain with stable alpha or beta configurations.
• Blasts from the sun? A filament eruption occurred at around 3 UTC on July 21 in the solar southwest.  It produced a narrow CMEs. Initial modeling and analysis efforts show an Earth miss. No other CMEs were observed in available coronagraph imagery.
• Solar wind conditions decreased, ending the period around 346 km/s, with the interplanetary magnetic field (IMF) remaining weak and Bz mostly northward. These are typical quiet solar wind conditions.
• Earth’s magnetic field has been quiet (Kp = 0 – 1). This calm is expected to shift tomorrow with the arrival of fast wind from the CH HSS. As of this writing, the Kp index is at 1.

Sun news July 21: See Earth block our view of the sun!

(11 UTC to 11 UTC)

Happy SDO eclipse season! Twice a year, because of the SDO spacecraft’s geosynchronous orbit, Earth obstructs its view of our star for between 30 and 70 minutes every day for several weeks. The current eclipse season began on July 10 and will end on August 7. Thankfully, solar activity is currently low, so we’re not missing too much. But we did see a filament eruption early yesterday that fired a blast of sun-stuff into space. This coronal mass ejection (CME) is expected to miss Earth, although forecasters note it could give us a glancing blow around July 22–23. Stay tuned.

• Flare activity is low. We saw only C-class (common) flares over the past day, mainly from AR4136, AR4143, and AR4149. The most significant was a C6.5 flare at 15:37 UTC on July 20 from AR4136, now nearing the sun’s western limb (edge). No M-class (moderate) or stronger flares occurred, but NOAA and the UK MetOffice are both forecasting a chance for M-class flares in the coming days.
• There are currently 12 sunspot regions on the Earth-viewed sun. Notable activity is concentrated in the northwest, where magnetic looping remains visible even as some regions rotate out of view. A promising region in the northeast continues to develop, and newly numbered AR4151, near the center of the disk, is also showing minor growth. Overall, magnetic complexity remains moderate, with some regions carrying beta or beta-gamma classifications.
• Blasts from the sun? One coronal mass ejection (CME) was observed in connection with the July 20 filament eruption, but it is not clearly Earth-directed. However, models do suggest a glancing blow is possible late on July 22 or early July 23. No other CMEs were observed in available coronagraph imagery.
• Solar wind conditions decreased from 440 km/s (984,252 mph) to about 400 km/s (894,775 mph). The interplanetary magnetic field (IMF) was moderate, with a brief southward (Bz) dip, though overall conditions were calm. A southward Bz component is favorable for auroras.
• Earth’s magnetic field has been quiet (Kp = 0 – 1). The current solar wind stream shows signs of diminishing influence from prior coronal hole activity. As of this writing, the Kp index is at 1.

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Bottom line: Sun news July 23, 2025. We had geomagnetic storming last night – and auroras – with more possibly on the way.