Jure Atanackov @jureatanackov.bsky.social · 26/08/2026There is clear coronal dimming associated with the M2.2 flare in AR 4513. It is not a major CME, but the launch position is virtually center disk, so it may be headed our way. Awaiting additional data. 030
Jure Atanackov @jureatanackov.bsky.social · 26/08/2026Boom! M2.2 flare from AR 4513. At the first glance it looks eruptive. 011
Jure Atanackov @jureatanackov.bsky.social · 25/08/2026Here is the full view of the CME from Stereo A (Cor2 coronagraph). Dense and very slow (<600 km/s in the NASA M2M model). 020
Jure Atanackov @jureatanackov.bsky.social · 25/08/2026Here we go. This is the NASA M2M WSA-ENLIL+Cone model prediction for the CME. A glancing blow, as indicated by lopsided EUV dimming. The arrival is expected on August 28th (Friday) around 10-11h UTC (+/-7h). Slow, not expecting much from this one. 030
Jure Atanackov @jureatanackov.bsky.social · 25/08/2026The CME is becoming visible in CCOR-1 images. The bulk is going east (though it seemed it would go more to the SE). There seems to be a faint component also to the W, although at this point it is not clear whether this is the same CME or not. More images are needed to see how wide the bulk is. 030
Jure Atanackov @jureatanackov.bsky.social · 25/08/2026The CME is emerging also in Stereo A Cor2 images. Looks *dense*. It seems the N-S extent is sufficent for a major Earth-directed component. The question is only how much SE-ward deflection there was. 020
Jure Atanackov @jureatanackov.bsky.social · 25/08/2026The CME is also clearly visible in GOES-19 SUVI EUV 284A images. It is propagating mostly towards the southeast, deflected at least in part by the coronal hole just SW of AR 4513. Looks like the bulk is going SE, awaiting coronagraph images for a more complete picture. 040
Jure Atanackov @jureatanackov.bsky.social · 25/08/2026Boom - CME! The M6.9 flare in AR 4513 was highly eruptive. Initial EUV images show a clear CME lifting from the AR. More soon! 041
Jure Atanackov @jureatanackov.bsky.social · 25/08/2026The flare peaked at M6.9. Awaiting EUV imagery to see if a CME was generated! We are in the direct strike zone. 030
Jure Atanackov @jureatanackov.bsky.social · 25/08/2026AR 4513 continues to have the potential for major flares. The inversion line with multiple magnetic deltas has been flaring over the past 24 hours, the trailing delta has been mostly quiet. The SWPC estimates a 10% chance of X-class flares today. 4513 is now in the prime firing position. 011
Jure Atanackov @jureatanackov.bsky.social · 25/08/2026AR 4513 has come alive over the past 12-18 hours with three low-end M-class flares: M1.7, M1.9, and M1.0. There is potential for a significantly stronger flare. 041
Jure Atanackov @jureatanackov.bsky.social · 24/08/2026This was a super frustrating event. The CME had major potential: solar wind speed was in the 1100-1250 km/s range, and the IMFwas truly exceptional. Bt briefly reached 93 nT (!!), but Bz - didn't cooperate. It bottomed out at below -50 nT in the sheath, but turned strongly positive in the flux rope. 151
Jure Atanackov @jureatanackov.bsky.social · 24/08/2026It has been 8 months since the last decent aurora show at 45°N MLAT … January 19th, 2026. If only that 90 nT Bt had ... 150
Jure Atanackov @jureatanackov.bsky.social · 24/08/2026The classic Solar Cycle 25 snooze fest continues as AR 4513 approaches the central meridian. The magnetic deltas are still there, but no significant flare (yet?). Hopefully that changes soon, as AR 4513 is approaching the prime firing position for an Earth-directed CME. 130
Jure Atanackov @jureatanackov.bsky.social · 24/08/2026If I had a time machine, this would be one of the things I'd want to do (in addition to buying a zillon bitcoin in 2009) is see aurora over medieval Europe. This is the woodcut of an auroral display over Nuremberg, Germany on October 5th, 1591 by Wolf Drechsel. 270
Jure Atanackov @jureatanackov.bsky.social · 24/08/2026"The impact of extreme geomagnetic storms can be twice as large as previously thought". Fresh (July) paper in Nature: doi.org/10.1038/s415... 021
Jure Atanackov @jureatanackov.bsky.social · 24/08/2026The sunspot number still hovers around 80, mostly propped by the scattering of active regions and spots near the central meridian. These will stay on the near side for another week. We don't know what's coming around the E limb, as the Solar Orbiter is currently on the near side of the Sun. 050
Jure Atanackov @jureatanackov.bsky.social · 24/08/2026Just how quickly an activity surge happens: this is the Sun from Oct 18th to Nov 4th, 2003. Note the *3* enormous & complex active regions popping up. This was later in the cycle than where we are currently at, so there is still hope that we will see more severe space weather before solar minimum. 071
Jure Atanackov @jureatanackov.bsky.social · 08/07/2025BOOM! Good Morning! M2.4 flare on the E limb from a new, incoming active region. 120
Jure Atanackov @jureatanackov.bsky.social · 07/03/2025Boom! M1.6 flare from active region 14016. Tiny active region, not so tiny flare. Coronal dimming was observed, mostly S-ward. More soon! 0110
Jure Atanackov @jureatanackov.bsky.social · 07/03/2025Wow! Why doesn't it do this during total solar eclipses? Spectacular eruptive prominence near the SW limb this afternoon (UTC)! Look at that loop! 071
Jure Atanackov @jureatanackov.bsky.social · 25/02/2025BOOM! Extremely long-duration M3.6 flare from active region 3998! X-ray flux was above M1.0 threshold for 1h20min! EUV (131A) imagery suggests a CME was launched, coronal dimming was evident, awaiting coronagraph imagery. 0162
Jure Atanackov @jureatanackov.bsky.social · 25/02/2025WOW! MASSIVE fast CME emerges from behind the W limb after a very long-duration M3.9 flare. The flare was likely much larger, mostly hidden behind the limb. 082
Jure Atanackov @jureatanackov.bsky.social · 23/02/2025BOOM! X2.0 flare from AR 4001! This comes after M4.9 and M1.2 flares earlier in the day. 191
Jure Atanackov @jureatanackov.bsky.social · 22/02/2025Why some big mid latitude aurora displays are purple and others red. In auroras close to the summer solstice oxygen reds mixing with nitrogen blues and violets, producing purple aurora. In auroras near winter solstice, the display is in Earth's shadow - no nitrogen blues, therefore no purples. 0111
Jure Atanackov @jureatanackov.bsky.social · 21/02/2025Two very impulsive M-class flares (M3.3 and M1.4) today from the very rapidly developing active region 4000. They were superimposed on a very long (6 hours and ongoing) surge in X-ray background flux, peaking near C7 and now at C4 level. More shortly! 020
Jure Atanackov @jureatanackov.bsky.social · 16/02/2025Within 10 minutes of the first photo the sky erupted in this! The exposure is actually 2x shorter, had I kept it the same the photo would have been blown out - that's how bright the substorm was! 191
Jure Atanackov @jureatanackov.bsky.social · 16/02/2025We who are stranded at central to low mid-latitudes know something special is going on when at 45° MLAT you begin to see distinct greens. This is the quiescent stage between the 1st & 2nd substorm of the 10-11 May 2024 G5 storm. Minutes before the sky absolutely erupted in shadow-casting aurora. 1121
Jure Atanackov @jureatanackov.bsky.social · 16/02/2025Absolutely insane eruptive prominence today! The CME it produced wasn't bad either. Too bad it's on the far side. 061
Jure Atanackov @jureatanackov.bsky.social · 15/02/2025Should we all adopt and use these? Do we already use these? Most are pretty common, but there are some pretty exotic ones here. 040
Jure Atanackov @jureatanackov.bsky.social · 15/02/2025Boom! M1.8 from active region 3990. Fairly close to the central meridian and there may have been a (minor) CME. More on this soon. 040
Jure Atanackov @jureatanackov.bsky.social · 14/02/2025Boom! Finally some flares: an M1.2 at 2:28 UTC from a new active region on the E limb and another M1.2 at 10:06 UTC from AR 3990. More soon! 050
Jure Atanackov @jureatanackov.bsky.social · 12/02/2025Incoming hot active region on the E limb! It blasted a C7.2 fairly long duration flare and a big, fairly fast CME. Impressive! Hopefully it stays active for another 5-7 days. 060
Jure Atanackov @jureatanackov.bsky.social · 11/02/2025AR 3981 is still waving goodbye as it rotates behind the W limb, this time with a long-duration C7.6 flare. 030
Jure Atanackov @jureatanackov.bsky.social · 11/02/2025Anyone else like this? No matter how many times I see aurora, I get all excited when I see it again - even if it's only faint rays and pillars poking just above the northern horizon. 391
Jure Atanackov @jureatanackov.bsky.social · 10/02/2025Fun fact: despite being a pretty exciting year aurora-wise, 2024 got off to a far slower start than 2025. Even if 2025 feels slow so far, and it does to me. In 2024 we got our first geomagnetic storm on March 8th. We have already had 4 in 2025 so far. Fingers crossed 2025 is even wilder than 2024. 161
Jure Atanackov @jureatanackov.bsky.social · 09/02/2025Update: Bz is holding around -10 nT with lots of fluctuations, but conditions remain favourable for aurora into mid latitudes, especially upper mid latitudes. High latitudes are getting a good show. 050
Jure Atanackov @jureatanackov.bsky.social · 09/02/2025Heads up Europe & North America! The high speed solar wind stream from the coronal hole is here, Bz is favourably negative & we are at G1 storm level. Bad news: the Moon is nearly full. Still, high and upper mid latitudes may see some good aurora activity tonight! 061
Jure Atanackov @jureatanackov.bsky.social · 08/02/2025The sunspot number is now dropping as the large complex of active regions, including 3981, slowly rotates behind the W limb. There are some active regions in the E half of the visible disk, but mostly simple with few spots. Magnetic loops over the E limb indicate new incoming active regions. 031
Jure Atanackov @jureatanackov.bsky.social · 07/02/2025Seems active region 3981 did the SC25 thing - it took a nap while on the central meridian and woke up a few days later. Numerous M-class flares over the past 24 hrs: M2.3, M1.6, M3.2 and M7.5. No significant CMEs from these flares, although the M7.5 possibly produced a very faint partial halo CME. 031
Jure Atanackov @jureatanackov.bsky.social · 06/02/2025You know what would be nice? A normal world & a proper G5 geomagnetic storm. Yes. That would be nice. 1175
Jure Atanackov @jureatanackov.bsky.social · 06/02/2025Meanwhile there was also a pretty impressive filament eruption (early in the day). The eruption and consequent CME were directed to the SW, well away from us. Just SC25 things. But it did look spectacular! 012
Jure Atanackov @jureatanackov.bsky.social · 05/02/2025Active region 3981 has retained the three magnetic deltas over the past 12-18 hours, but has only produced a single M-class flare (M2.7). This is slowly turning into a SC25 classic - active east of the central meridian (CM), takes a nap while crossing the CM, wakes up later (?). 030
Jure Atanackov @jureatanackov.bsky.social · 05/02/2025Active region 3981 over the past 24 hours: overall the region remains mostly unchanged, the intermediate and trailing parts are complex with multiple (3) magnetic deltas, there is potential for further flares. SWPC estimates a 20% chance for an X-class flare today. 061
Jure Atanackov @jureatanackov.bsky.social · 05/02/2025Active region 3981 has prodiced only a single (super short duration and impulsive) M-class flare over the past 20 hours. It is capable of way more. 151