M8.2 solar flare, Strong G4 geomagnetic storm watch

183 sva_ 45 6/1/2025, 4:43:54 PM spaceweatherlive.com ↗

Comments (45)

Animats · 15h ago

PJM issued a geomagnetic disturbance warning, then an action. No emergency actions, and it's already over.

    Msg ID:     104606
    Message Type:  Geomagnetic Disturbance Action 
    Priority:     Action
    Effective Start Time:  06.01.2025 09:31
    Effective End Time:  06.01.2025 12:25
    Regions  COMED

    A Geomagnetic Disturbance Action has been issued as of 09:31 on 06.01.2025 to protect
    the power system from damage or disruptions due to increased geomagnetic activity.

Times are "Eastern Prevailing Time", which is Eastern Daylight Time right now.

Background:

These messages are from the US east coast power grid control room in Valley Forge, PA sending to people at generating stations and other key control centers. This is a slow-moving event. If the grid was stressed, there would be "Pre-Emergency Load Reduction" and "Conservative Operation" actions ordered. If there was real trouble, there would be many more actions. But things never got beyond preparing for trouble.

A geomagnetic disturbance event in 1989 caused transformer damage leading to outages. The solar flux going between power lines and conductive ground induces DC currents into the ground and lines, so that ground potential is different at different points. This causes partial saturation of transformers, and heating. That wasn't noticed until it was too late. So now, DC current in some key AC lines is monitored continuously, so power levels can be reduced if necessary.

Training materials for understanding this:[1] Start at slide 21.

Background info on how a power grid works.[2] Start with "PJM 101"

[1] https://pjm.adobeconnect.com/p63ultsdb2v/

[2] https://www.pjm.com/training/training-resources

idatum · 9h ago

> Times are "Eastern Prevailing Time", which is Eastern Daylight Time right now.

I'm trying to recall when I last ever saw "Eastern Prevailing Time" used.

Can anyone share why it's used?

I see more use of ET over that (for Eastern US) or better yet UTC/GMT.

xhrpost · 10h ago

> So now, DC current in some key AC lines is monitored continuously...

Can power lines have multiple currents in them at once? What would that mean for when the AC phase is moving opposite the DC direction?

andy99 · 10h ago

AC is a sinusoid at 60/50 Hz. In principle, adding a DC current is just an offset, so e.g. if you had 1 Amp of AC current it would look like a sine wave 1 Amp high (actually sqrt(2)=1.414 high using the usual convention but that's not important) and the wave would be centered at 0A so go from -1(.414) to 1(.414). If you had a DC current of -1A on top of that, it would just be offset by that amount, so would look like a sine wave with a minimum of -2.414 and a maximum of .414.

Tldr, DC is just like an offset to the voltage or current waveform which is itself a sine wave.

globular-toast · 3h ago

Electrical conductors are basically reservoirs of electrons that can move around freely. Think of a body of water like the ocean. There is a lot of movement happening all at the same time: the tides, the waves, rip currents etc.

A wire is an essential one dimensional conductor; the electrons can move only backwards or forwards. Think of a narrow channel of water like a canal or river. A canal has no current, while a river has a direct current: it always flows one way. But a tidal inlet has an alternating current. The net flow of water is zero, but there is still a constant movement of water, backwards and forwards.

At a tidal estuary both things are happening: there's a DC component caused by net egress of water and an AC component caused by the tide.

The analogy doesn't really work because bodies of water also have capacitance. Wires are more like pipes. But hopefully you get the idea. Another way to think of it is like shouting in the wind, if you know how sound works.

Look into Fourier transforms if you're interested in learning more.

zrm · 12h ago

> https://pjm.adobeconnect.com/p63ultsdb2v/

Apparently my browser does not support some content in the file I'm trying to view and I'm instructed to use, among other things, "Firefox undefined or later". Which may or may not be what I was trying to use to begin with.

Though it seems to work anyway, so okay then.

zoky · 7h ago

> "Firefox undefined or later"

Honestly, you should really upgrade to at least Firefox Null for the security updates, or even Firefox NaN if you’re okay with being on the bleeding edge.

Animats · 12h ago

That PJM training material uses some ancient Adobe product. Works fine, though.

qwertox · 16h ago

M8.2 is in the upper medium range (M = M1.0 to M9.9). Next comes X1 which is 10 times stronger than M10. M2 is 10 times stronger than M1.

We might see several of these per year during a solar maximum. So maybe we get some nice auroras.

Edit, TIL: Though the G4 is a different issue, which classifies the impact of a solar flare on our earth. These range from G1 (minor) to G5 (extreme). This means that it can disrupt radio communications and GPS, put stress on power grids and, interestingly, increase satellite drag. G4 storms are rare events and occur only a few times per 11-year solar cycle.

nozzlegear · 15h ago

> G4 storms are rare events and occur only a few times per 11-year solar cycle.

Did you mean G5 storms? If I'm reading NOAA correctly, we get about 100 G4 storms per cycle, but only 4 G5 storms per cycle.

https://www.swpc.noaa.gov/noaa-scales-explanation

dylan604 · 15h ago

> interestingly, increase satellite drag.

was reading something about this last week. originally, I assumed that the satellite electronics were getting whacked, but that wasn't the actual reason. these storms can heat the atmosphere causing it to expand/swell during the heating which causes extra drag requiring faster than anticipated use of fuel for station keeping.

just another one of those issues of just how everything in the universe "works together" in the most interesting ways.

perihelions · 13h ago

A while back an entire Starlink launch was lost due to this atmospheric inflation,

https://news.ycombinator.com/item?id=30267587 ("Starlink lost 40 satellites to a geomagnetic storm (spacex.com)", 495 comments)

OskarS · 15h ago

I've read there was a huge solar flare in the 19th century that knocked out telegraph equipment all over the world. Do we know how strong that event was on that scale?

sva_ · 14h ago

You're probably referring to the Carrington Event

https://en.m.wikipedia.org/wiki/Carrington_Event

The instruments to measure the strength of solar flares didn't exist, but I think it's estimated between X40 to X50.

For comparison, last may the strongest flare was X8.7

https://en.m.wikipedia.org/wiki/May_2024_solar_storms

yread · 16h ago

You can kinda follow news about it on

https://community.spaceweatherlive.com/topic/3947-ar14100-m8...

Although it often sounds like people throwing fancy words around just to sound smart. And their predictions mostly dont work out

petee · 15h ago

NOAA Experimental Aurora Viewline prediction for tonight/tomorrow night -- https://www.swpc.noaa.gov/products/aurora-viewline-tonight-a...

mobbin · 16h ago

I know absolutely nothing about solar weather beyond aurora visuals being a possible outcome depending on where you live. I missed the last chance to see at my latitude (rare) and don't want to miss again.

What could I subscribe to so as to be notified when such events happen?

mikeocool · 15h ago

The Aurora app on iOS can set to send a critical notification when you’re likely to see it in your location.

It alerted me (in New York) this morning at about 4AM — though I slept through it.

pyrophoenix · 16h ago

It means between an hour and 9 hours from now, we might have a Aurora down to Berlin level at 100%. Now the weather is not the best. More information in 2 hours.

BenjiWiebe · 16h ago

Note that this was published yesterday. The geomagnetic storm is underway right now.

lucasban · 15h ago

I’ve been using the “My Aurora Forecast & Alerts” app, which is pretty good. I’m using the pro version, but I think the main difference was removing some ads.

AStonesThrow · 16h ago

https://www.swpc.noaa.gov/products/alerts-watches-and-warnin...

https://www.swpc.noaa.gov/communities/space-weather-enthusia...

https://www.swpc.noaa.gov/content/subscription-services

olddustytrail · 16h ago

For the UK there's https://t.me/aurorawatchuk on Telegram but I guess solar weather is globally applicable.

n3uromancer · 16h ago

https://x.com/JAtanackov/

cogogo · 10h ago

On October 10th 2024 there was an x1.8 event and it was basically right at us. First time I’d seen the aurora - happened to be on cape cod at the time where the light pollution isn’t so bad. Was pretty amazing with the naked eye but absolutely incredible in long exposure photos.

sva_ · 15h ago

> CME Passage Continues; G3-G4 Still Possible Tonight, June 1st

https://www.swpc.noaa.gov/news/cme-passage-continues-g3-g4-s...

NooneAtAll3 · 15h ago

if I read all the websites correctly... it has already ended??

---

NOAA map (https://www.swpc.noaa.gov/products/aurora-30-minute-forecast) shows huge auroras were at ~7-9 UTC and now are gone

https://solarham.com/ says "arrived faster than expected" and "threshold was reached at 08:00 UTC"

and the website linked, the https://www.spaceweatherlive.com/en/.html says "14:00 UTC - Geomagnetic activity Severe G4 geomagnetic storm (Kp8)" followed by "17:30 UTC - Geomagnetic activity Minor G1 geomagnetic storm"

sva_ · 15h ago

NOAA: "CME Passage Continues; G3-G4 Still Possible Tonight, June 1st"

https://www.swpc.noaa.gov/news/cme-passage-continues-g3-g4-s...

hinkley · 14h ago

My brain tried twice to turn this title into the name of a new nvram device.

a012 · 7h ago

M8.2 is also a very old model of Leica M

transcriptase · 16h ago

Hams: How’s the RF propagation with this one?

geerlingguy · 16h ago

My favorite site for tracking the metrics is https://solarham.com/

geoffeg · 11h ago

https://solar.w5mmw.net/ is also nice for a quick overview.

AStonesThrow · 16h ago

NOAA's gotchu covered!

https://www.swpc.noaa.gov/communities/radio-communications

volemo · 13h ago

Hey, m8, it’s a big solar flare!

kapnap · 16h ago

Good luck to any directional drillers out there trying to drill your well blind.

JumpCrisscross · 16h ago

kapnap · 7h ago

It's kind of a running joke when you work as a Drilling Engineer and the Directional Driller says they can't confirm their coordinates due to magnetic storms.

https://www.usgs.gov/communications-and-publishing/news/gett...

WJW · 14h ago

It's a reference to the "Armageddon" movie from 1998 when a bunch of oil rig drillers get recruited into being astronauts for plot reasons. It was a decent enough movie but nothing you need to look up unless you have an unhealthy obsession for Arwen from Lord Of The Rings.

kapnap · 7h ago

Negative - when directional drilling a well, a magnetic storm can actually cause you to lose signal and halt the entire drilling process. It's kind of a running joke when you work as a Drilling Engineer and the Directional Driller says they can't confirm their coordinates due to magnetic storms.

https://www.usgs.gov/communications-and-publishing/news/gett...

timschmidt · 10h ago

I always felt that Armageddon occupied this uncanny valley of Hollywood cheese. Too much to suspend disbelief, not enough to be making fun of itself. Always loved "The Core" for being the same sort of film but falling into the second camp.

AStonesThrow · 9h ago

Don’t forget Deep Impact, sort of a summer companion blockbuster, but which “astronomers said was more accurate”, could feed your Hobbit obsessions, and NASA went on to name a space probe after it!

https://en.wikipedia.org/wiki/Deep_Impact_(film)

https://en.wikipedia.org/wiki/Deep_Impact_(spacecraft)

_Microft · 15h ago

If I had to guess, I would say that Earth's magnetic field is used in directional drilling to tell which way your drill head is going and that the solar storm distorts Earth's magnetic field.

SoftTalker · 14h ago

Wonder why they don't use gyros. Too much vibration?

_Microft · 13h ago

They might be - this was only an attempt to make sense of the first comment in the context of this submission.

If you are useful, it doesn't mean you are valued (betterthanrandom.substack.com)

The Visual World of 'Samurai Jack' (animationobsessive.substack.com)

ReasoningGym: Reasoning Environments for RL with Verifiable Rewards (arxiv.org)

The Princeton INTERCAL Compiler's source code (esoteric.codes)

How to post when no one is reading (jeetmehta.com)

Is "The Phoenician Scheme" Wes Anderson's Most Emotional Film? (newyorker.com)

Root shell on a credit card terminal (stefan-gloor.ch)

Show HN: System Prompt Learning – LLMs Learn Problem-Solving from Experience

In POSIX, you can theoretically use inode zero (utcc.utoronto.ca)

LFSR CPU Running Forth (github.com)

A man who sailed round the world with a chicken (2019) (theguardian.com)

I made a chair (milofultz.com)

LibriVox (librivox.org)

Is It JavaScript? (blog.jim-nielsen.com)

How can AI researchers save energy? By going backward (quantamagazine.org)

Cinematography of “Andor” (pushing-pixels.org)

TPDE: A Fast Adaptable Compiler Back-End Framework (arxiv.org)

The Rise of Judgement over Technical Skill (notsocommonthoughts.com)

HeidiSQL Available Also for Linux (heidisql.com)

Understanding Consistency in Databases: Beyond the Basics (medium.com)

What works (and doesn't) selling formal methods (galois.com)

The Zach Attack Scratch 'N Solve Puzzle Pack (coincidence.games)

Writing your own C++ standard library part 2 (nibblestew.blogspot.com)

Show HN: Moon Phase Algorithms for C, Lua, Awk, JavaScript, etc. (github.com)

Show HN: I built an AI Agent that uses the iPhone (github.com)

Hip: C++ Heterogeneous-Compute Interface for Portability (github.com)

Gabon longs to cash in on sacred hallucinogenic remedy (phys.org)

Progressive JSON (overreacted.io)

A new generation of Tailscale access controls (tailscale.com)

When Fine-Tuning Makes Sense: A Developer's Guide (getkiln.ai)

Nitrogen Triiodide (2016) (fourmilab.ch)

Show HN: Yet another tmux cheat sheet (tmuxai.dev)

Revisiting Loop Recognition in C++ in Rust (blomqu.ist)

Estimating Logarithms (obrhubr.org)

How I like to install NixOS (declaratively) (michael.stapelberg.ch)

Google AI Edge – On-device cross-platform AI deployment (ai.google.dev)

RenderFormer: Neural rendering of triangle meshes with global illumination (microsoft.github.io)

Show HN: MBCompass – Android Compass App (github.com)

Show HN: Agno – A full-stack framework for building Multi-Agent Systems (github.com)

How reliable are MicroSD cards? (old.reddit.com)

The £1B British AI dream that collapsed in controversy (telegraph.co.uk)

Making maps with noise functions (2022) (redblobgames.com)

Atari Means Business with the Mega ST (goto10retro.com)

Codex CLI is going native (github.com)

AI Persona Groupthink Makes Group Talk More Realistic (arxiv.org)

M8.2 solar flare, Strong G4 geomagnetic storm watch (spaceweatherlive.com)

New adaptive optics shows details of our star's atmosphere (nso.edu)

Structured Errors in Go (2022) (southcla.ws)

Show HN: Patio – Rent tools, learn DIY, reduce waste (patio.so)

A Lean companion to Analysis I (terrytao.wordpress.com)

M8.2 solar flare, Strong G4 geomagnetic storm watch

Comments (45)