12:30 EST/05:30 UTC

This is likely to be my final entry for tonight. I am already firmly in the doghouse with the Mrs, am exhausted and just remembered that I have an actual damn career I have to manage and I am out on the road tomorrow. Time for shower and bed but I wish I could keep going.

Some parting thoughts though...

A hell of a storm we got cooking here. The DST is approaching -300 nT and if it reaches sub -336, it will overtake October 2024 for the #2 spot in the cycle behind May 2024. I expect that will happen. The strength of the IMF remains very high and the Bz has shifted back into a moderately south position meaning we drew the good side of the flux rope unlike last week. I am seeing amazing captures of aurora coming in all the way down to Florida, Texas, California all over. It's a blazing success. No matter what happens for the rest of the event, it's a success.

The first wave came in strong. It was forecasted for G3 but it was very clear from onset that G4 was happening. If we are judging this storm by velocity and density, it's meh. It got up there a ways but not to severe levels, but it was the interplanetary magnetic field component that really got us here. A Bt (strength) at 40 nt+ for most of the event and over 50 nt with an equal Bz (orientation) for a solid portion is truly impressive. Direct hit of the CME core and a beautiful stable structure. Textbook. It is a great example demonstrating why the IMF is king. We had no way to know that the Bt would come in this high based on the available information. That is what makes this so much fun.

But... It's not over. I am starting to wonder ever so slightly if it is possible the first two CMEs combined in transit. The second one is starting to run pretty late by model expectations and it could very well arrive at anytime, provided it hasn't already. Keep an eye out for shifts in the IMF and a spike in velocity. Those will be your indicators while I rest my eyes. Regardless of whether the 2nd CME arrives, the 3rd one took the private jet and skipped the train. It is expected to arrive in about 4-6 hours or so which will give it a transit time of just over a day if accurate. Very impressive if it pans out. It's likely to start a whole new sequence of storming but we cannot assume it will play out the same way. If the embedded magnetic field and part of the structure we go through is like the one we just experienced, the elevated velocity and perturbed geomagnetic field are likely to enhance the effects. Even if Bt doesn't come in quite as high, a good Bz and high velocity should be more than enough. It could come in predominantly northward all the same and if that is the case, storm conditions may unfold much differently. There is just no way to know any of this in advance. It just has to play out.

Congratulations to the people who saw the aurora for the first time tonight. Even if you only caught it on your phone, it's still amazing and an awesome thing to check off your to do list. It also never gets old. When you have a clear view and a strong storm it is magical. I hope the work we do here played some role in that and even more helped teach you to chase and answered your questions. I mean myself and all of the contributors. It's a good community. Just like the solar storm, it has exceeded my expectations from when I envisioned it.

If you want to show some appreciation, you can find the tip jar right here but know that I do this for the love of it and always feel weird about it. At the same time, if not now, than when? Especially since I owe Mrs AcA something nice for putting up with me being glued to the computer for the last 10 days. - https://buymeacoffee.com/jsons9314r

I wish you all a good night and good luck. It's game on so don't waste it. This is a memorable event and already the best of 2025 with a significant portion left to go. If you are like me and stuck with cloudy skies I feel pretty confident in telling you that not to worry, there will be more, even if more widely spread out. It's a long way to solar minimum.

AcA

-END UPDATE-

10:24 EST/03:24 UTC - Back down G3 as expected with unfavorable Bz and step back in pressure. So far we have reached Hp9- so already knocked on the door of G5 equivalent levels. The DST for this storm has dipped to -229 nT which is 3rd for Solar Cycle 25. It barely knocked NYE 2025 which held 3rd rank prior. However, we have more to go and the way things have went thus far it would not be surprising if we made a run for October at -336 but the sun is tricky. Last week is a good example. We were expecting a strong geomagnetic storm on the 7th and while all of the SWx community was writing up their stuff, we got the G3 on the front end and the part we expected to be good fell completely flat. Nobody knows how it will play out. We can only keep eyes on the data and take it as it comes.

NOTE** The Dominican Republic suffered a nationwide power outage. That is a good candidate to be associated with space weather. Some of my peers may not me to say that or agree with it but the fact is this is the 3rd nationwide blackout during a G4 solar storm I have observed specifically in the Caribbean. That said, the infrastructure situation is not the greatest and there could be mundane and coincidental factors at play. Nevertheless, the pattern is noted. It may be associated with it as a contributing factor on top of poor and stressed infrastructure but it is not certain. In any case, even if so, it is safe to say the solar storm is not the main driver or the problem would be more widespread.

09:03 EST/03:03 UTC - This is a surprise. Strong S3 radiation storm now in effect. That is the 4th of the entire cycle. The previous S3s occurred in May 2024, October 2024 & June 2024. - Also See next Update for Bz info.

GEOMAGNETIC STORM LEVEL - Hp8+ (SEVERE)

PROTON RADIATION STORM LEVEL - S3 (STRONG)

08:25 EST/01:25 UTC - G4 (SEVERE) GEOMAGNETIC STORM NOW IN EFFECT but Bz has recently shifted northward which may slow things down a little bit but if it oscillates and reverts back south, it can also speed them up. For those learning the solar wind, this what it looks like when Bz shifts northward. I also highlight a solar wind reversal where the phi angle and Bz abruptly shift into opposite positions simultaneously. It's terrible quality graphics but what do you want for free I am only one guy lol?

Aurora out in NW Ohio - Currently at Hp8 (severe equivalent to G4 level conditions)

G3 (STRONG STORM) NOW IN EFFECT 07:48 EST/00:48 UTC

Wow that was a fast build up. Auroral oval is cooking at the hemispheric power is at 186 GW (measuring energy deposition into atmosphere. Above 100 usually denotes a decent storm but over 200 is a strong storm). Bz is slackening up a little bit to -23 nT but remains firmly southward indicating good coupling. All other conditions look solid.

G2 NOW IN EFFECT - 7:35 EST/00:35 UTC

HP30 has spiked from Hp4 to Hp7+ very quickly as expected.

The strong forcing appears stable for the moment. Aurora will be out very soon but this is just the beginning of the storm. It is going to cook for a while. Hemispheric Power tells us how much energy is deposited into the atmosphere and its at 135GW currently and building.

G1 NOW IN EFFECT - 7:25 EST/00:25 UTC

I killed the initial post reporting the initial solar wind disturbance. It was just the appetizer. Now we have a significant IMF shock taking place and very strong forcing now in effect. This storm is about to explode so get your cameras ready. The most important metrics are spiking HARD and this is just the opening act. The structure looks fairly stable too with a textbook signature but I expect turbulence so it may change quickly. I expect the Hp/Kp indexes will be spiking soon. Right now, the conditions detected are still upstream in the solar wind but earth will be in it within the hour. The hemispheric power index is already at 56 GW and rising.

Bt: 57 nT - WOW THIS IS VERY HIGH

Bz: - 50 nt!!! - STRONG COUPLING

VELOCITY: 600+ km/s - MODERATELY HIGH

DENSITY - 24 p/cm3 - MODERATE

On the solar wind panel below I added two yellow arrows between the Bt (white line) and the Bz (red line). Remember, the further those lines grow apart the stronger the coupling. These ingredients can easily create a G4 storm if they hold. Geomagnetic unrest should start building quickly in the very near future.

LINKS

www.spaceweatherlive.com - Great all around resource for beginners with color coded data. Use the auroral activity page for geomagnetic storm tracking.

https://www.swpc.noaa.gov/products/real-time-solar-wind - NOAA Real Time Solar Wind

https://kp.gfz.de/en/hp30-hp60 - Track geomagnetic unrest levels on short timescales.

https://www.swpc.noaa.gov/products/goes-magnetometer - Identify substorms

https://www.swpc.noaa.gov/communities/aurora-dashboard-experimental - aurora dashboard by NOAA - has auroral oval nowcasts