Level S4 solar radiation event

(swpc.noaa.gov)

210 points | by WorldPeas 5 hours ago ago

78 comments

  • jjcm 2 hours ago

    If anyone is interested in what "G4" means in context, here's the scale: https://www.swpc.noaa.gov/noaa-scales-explanation

    • irthomasthomas an hour ago

      We are at kp 8.67. The Carrington event was a kp 9

      • ianruh 40 minutes ago

        I am not an expert, but it’s worth noting that the kp index has a maximum value of 9. So though the Carrington event had a kp of 9, its intensity on the related (but not capped) HP30/HP60 scale [1] would likely have been higher. [1] https://kp.gfz.de/en/hp30-hp60

        • repeekad 21 minutes ago

          Queue Chernobyl documentary clip measuring the radiation as low because that’s as high the meter went

          • celsoazevedo 5 minutes ago

            3.6 roentgen. Not great, not terrible!

    • 8bitsrule an hour ago

      G4: " Induced pipeline currents affect preventive measures, HF radio propagation sporadic..."

      G5: " Pipeline currents can reach hundreds of amps, HF (high frequency) radio propagation may be impossible in many areas for one to two days..."

    • xeckr an hour ago

      Looks like we get these for about 60 days for periods lasting 11 years.

    • neonmagenta an hour ago

      so more of a 'bad storm here and there' level?

  • bartman 2 hours ago

    We had intense aurora in Berlin, Germany. Green clouds dancing in the sky levels. Started around 22:10 local time or a bit earlier, and at this point there's only a faint red/green glow remaining.

    • rob74 2 hours ago

      Yeah, there were auroras even as far south as Munich. Maybe not as intense, but it's the first aurora I ever saw, so I can't really judge...

      • ccozan an hour ago

        I am south-west of Munich and with a perfect clear sky I could only see stars, one meteor, and that's it.

    • fluxflexer an hour ago

      Just spend an hour outsite (Northern Germany, 01:00 MET). Unfortunately nothing to report, neither visual nor on camera. Maybe I just went to late and missed the show. I hope you habe more luck in Canada and the US!

      • jacquesm an hour ago

        It's pretty subtle right now here in NL but I can still see it with the naked eye. Mostly greenish haze that fades in and out.

    • karim79 an hour ago

      I was just out at a dog park and saw nothing! We have clear skies. I can't believe I missed this.

    • Tachyooon 2 hours ago

      Could you see it from the inner city or only closer to the edges?

      • bartman 38 minutes ago

        Friends who live in Kreuzberg and Friedrichshain could see it pretty well. I'm a bit further south within Berlin where skies are minimally darker, but between 10pm and 11pm it was so bright that light pollution didn't matter.

        Funnily enough, despite having lots of alerts set up it was my mom who texted me from northern Brandenburg as she spotted it after getting an alert from RegenRadar, of all apps...

    • paulmist 2 hours ago

      Also seen in the Netherlands!

  • miduil 3 hours ago

    Nice, you can already see some solar flares in Austria again.

    https://www.foto-webcam.eu/webcam/kleinfleisskees/

    https://www.foto-webcam.eu/

  • frzen 2 hours ago

    I had the most intensely coloured lights visible in the west of Ireland. I've seen them a few times before but never like this. Phones were capturing them in video not just long exposures.

    Not sure what the best service is to be alerted ahead of time. Apparently it'll be strong here again at 6am according to some of the apps some random people were waving around.

    • ortusdux an hour ago

      There are several apps that do a good job of alerting users. I use "Aurora Pro", which I prefer because it checks cloud cover and lets you set alert thresholds based on viewing probability.

      • King-Aaron an hour ago

        I woke up to a notification from aurora pro today, I'd forgotten I had the app. This would explain it

  • nbf_1995 13 minutes ago

    Title says "S4" solar radiation event, but the linked page says "G4" geomagnetic storm

  • Animats 2 hours ago

    PJM had some geomagnetic disturbance warnings, but did not progress to the alert stage or grid re-configuation actions. So, no US power grid problems.

        104955 Warning Geomagnetic Disturbance Warning 01.19.2026 14:30 
        PJM-RTO
        A Geomagnetic Disturbance Warning has been issued for
        14:30 on 01.19.2026 through 16:00 on 01.19.2026 .
        A GMD warning of K8 or greater is in effect for this period. 
        End time: 01.19.2026 16:00 
    
    (All times are prevailing Eastern US time)

    I've posted on this before, for other warnings. Not going to repeat that.

  • Kunsang 13 minutes ago
  • WhitneyLand an hour ago

    How rare is this?

    G4 storms are ~100 per solar cycle (~11 years).

    So roughly 9 G4 events/year on average.

    • burnt-resistor 24 minutes ago

      Like 20-25 years rare according to some space weather youtuber.

  • bashtoni 2 hours ago

    Australian Bureau of Meteorology advisory for visible aurora: https://www.sws.bom.gov.au/Aurora

    • aussieguy1234 24 minutes ago

      Worth noting that Kp, which many talk about in discussions online, is more or less useless for anyone in Australia or the southern hemisphere. Lots of beginner Aurora chasers here get tripped up by that.

      What is useful is KAus and the G index, KAus is shown on this page, so thats what i'll be tracking.

    • jp0d 2 hours ago

      Are there any resources to track Aurora sightings or predicted sightings?

      • stubish 2 hours ago

        At the bottom right of that page is a subscribe link, with a number of different alerts and lists to subscribe to.

    • hahahahhaah 2 hours ago

      Is that tonight or last night?

      • bashtoni an hour ago

        It was only issued this morning Australian time, so I presume it's for tonight.

  • rediguanayum 2 hours ago

    Moon should be good too to see Aurora tonight: waxing crescent 1% https://www.moongiant.com/phase/today/

  • drmpeg an hour ago

    Although everyone is interested in visible aurora, the proton flux is also really impressive. It peaked at 37,000 pfu at 1910Z. The highest ever recorded was 43,500 pfu in March 1991.

  • JoeDaDude 38 minutes ago

    There is a video update from the NOAA Space Weather Prediction Center. (I could only find this on Facebook) https://www.facebook.com/reel/1190509063198524

  • dschuessler 3 hours ago

    This page looks like an accessibility nightmare. The entire warning text is an image. There is no transcription present for screen reader users. I did not expect this from a government website.

  • ComputerGuru 2 hours ago

    Do you need long exposure to make it visible with a camera? How does that work in the presence of light pollution?

    • thebruce87m 2 hours ago

      Tonight I could see the colours without the camera but it definitely stands out more with the long exposure of the camera.

      Even with lights in the direct line of the shot you you can get good results - presumably the phone is doing HDR to achieve this.

    • Macha an hour ago

      Local light pollution normally makes it hard to see with anything short of long exposure, but today it was naked eye visible and regular photos also captured it.

  • PlatoIsADisease 2 hours ago

    Years ago I was concerned about this and made a plan with my wife for what to do if she was at work.

    But now we have a bunch of kids in different schools and haven't updated our plan.

    Does anyone have a plan for what happens if we have a really bad event?

    • hnuser123456 2 hours ago

      A really bad event would be that long-distance transmission lines act like antennas and pick up millions of volts and blow up all the transformers.

      I don't know how much you can plan for that other than "if it happens, try to get home", and then all the usual prepper stuff.

    • myself248 an hour ago

      Pray for clear skies and go out and watch the beautiful aurora, silly!

      Depending on the kids' ages, you can teach them quite a lot about the Earth's magnetic field and why the aurora concentrates at the poles, how the high-energy particles light up the sky (it's a lot like a neon light), and how the atmosphere shields us from any danger despite the spectacular show.

    • rootusrootus 2 hours ago

      For a really bad event that managed to blow a lot of transformers (presumably due to grid operators not seeing it coming) ... well, take up farming.

    • Tepix 2 hours ago

      Buy a bit of extra food and water.

      • y1n0 an hour ago

        And toilet paper! Rolls and rolls of toilet paper!

    • swader999 2 hours ago

      First rule of fight club...

    • fuzzer371 2 hours ago

      Keep a couple days water and food on hand, go up to the pub, have a pint, and wait for this all to blow over.

      • JoshTriplett 2 hours ago

        With how much modern cars rely on electronics, I would not try to drive during such an event.

        • throwaway81523 32 minutes ago

          That's a safety feature. It prevents you from drinking and driving if you go to a pub during a solar flare. :)

        • whyleyc an hour ago

          It’s ok - The Winchester is within walking distance.

          • jrgd 24 minutes ago

            Omg i watched this yesterday!

        • jrgd 25 minutes ago

          No one would drive to the pub anyway. Better walking back home…

        • lxgr 2 hours ago

          Solar flares are only dangerous to very long conductors.

  • tigerlily 2 hours ago

    Hopefully it's clear space weather for Artemis II coming up. I wonder what they do if it's inclement en route?

    • perihelions an hour ago

      There's not that much they can do. It's often discussed that if the extreme August 1972 solar storm had overlapped with an Apollo mission (it didn't), it would have acutely sickened the astronauts.

      https://en.wikipedia.org/wiki/August_1972_solar_storms#Human...

      > "Had a mission been taking place during August, those inside the Apollo command module would have been shielded from 90% of the incoming radiation. However, this reduced dose could still have caused acute radiation sickness if the astronauts were located outside the protective magnetic field of Earth, which was the case for much of a lunar mission. An astronaut engaged in EVA in orbit or on a moonwalk could have experienced severe radiation poisoning, or even absorbed a potentially lethal dose."

      The Orion capsule's contingency plan looks something like this:

      > "To protect themselves, astronauts will position themselves in the central part of the crew module largely reserved for storing items they’ll need during flight and create a shelter using the stowage bags on board. The method protects the crew by increasing mass directly surrounding them, and therefore making a denser environment that solar particles would have to travel through, while not adding mass to the crew module itself."

      https://www.nasa.gov/missions/artemis/orion/scientists-and-e...

  • _carbyau_ 2 hours ago

    Weirdly, while the site in question is "blaring klaxons!" there are more "cool night lights!" posts than concern.

    • zamadatix 2 hours ago

      Unless you're in space, a large scale electrical operator, or relying on HF radio there isn't much reason to be interested other than the lights for a G4 (what this is currently classed as).

    • rzzzt an hour ago
    • guerrilla 2 hours ago

      > while the site in question is "blaring klaxons!"

      No, it isn't. It clearly says everything is under control but it would be good to keep an eye on it.

  • aliljet 2 hours ago

    I wonder if we're going to see an aurora over Seattle tonight?

  • burnt-resistor 26 minutes ago

    Up to G-5 possibly. Cell phone visible in dark areas throughout most of CONUS.

    It was mentioned that air travel ionizing radiation exposure increases during geomagnetic storms. I'd consider pausing travel for a couple of days to not be a guinea pig because there's not enough data to consider it safe. If anyone absolutely must fly tonight, it'd be interesting if they were to take a high sensitivity dosimeter to see what happens.

  • aussieguy1234 2 hours ago

    I'll be going out tonight if this continues into Australian night time hours.

    At this strength, I could see the full display including colors with my naked eye in Melbourne, May 11th 2024. This storm is slightly stronger than that event.

  • zahlman 3 hours ago

    It seems that the peak was several hours ago, and I haven't observed any effects from it...

    • guerrilla 2 hours ago

      The peak was originally supposed to be 6-7 hours from now... it's still showing KP 8 here though, so I'm not sure what's going on. It could get more intense.

  • uticus 4 hours ago

    Possible aurora visible through central US tonight

  • ferguess_k 2 hours ago

    Darn Montreal is still too south. Wish I were in Winnipeg.

  • tramtrist an hour ago

    We never get aurora in Japan :(

  • cbeach 2 hours ago

    Probably a stupid question, but should I unplug my EV? (UK)

    • qayxc an hour ago

      No need. Wrong type of solar event. You might be able to see auroras, though. I saw some a couple of hours ago.

    • jacquesm an hour ago

      No.