I hope someone can ELI5. I mean, we're told that sunlight/etc we see is 8 minutes old - it took 8 minutes to get from the sun to the earth. The radiation, light, etc all travel at the speed of light, neither slower nor faster.
If we can see anything on the sun, it happened 8 minutes ago. It's not like we're looking out over a Kansas field and see a tornado coming.
Further, there's this from a quick Google (while attempting to answer this question myself), from Oct 13 2023:
"How much warning do we have for solar storms?
So it should come as no surprise that a team at NASA has been busily applying AI models to solar storm data to develop an early warning system that they think could give the planet about 30 minutes' notice before a potentially devastating solar storm hits a particular area."
So how are we getting a notice one or two days in advance here? Is the sun currently ejecting matter into space, intersecting the place in our orbit we'll occupy tomorrow (or the next day)? Or is this like predicting a volcanic eruption, basing it on other observable behavior?
The charged particles that affect our electrical and electronic systems have mass and therefore cannot travel at the speed of light... We can see the visible light effects of a flare and know that the slower-moving particles that will cause actual damage are on the way.
This delay is due to the fact that solar storms consist of charged particles (mostly electrons and protons) ejected from the Sun. These particles are not electromagnetic radiation (like light), so they don’t travel at the speed of light. Instead, they are propelled by the solar wind, a continuous stream of charged particles that flows outward from the Sun.
The solar wind travels at varying speeds, but it typically takes several days for the charged particles associated with a solar storm to travel from the Sun to Earth. The exact time depends on the speed of the solar wind and the distance between the Sun and Earth.
So, although light from the Sun reaches us in just over eight minutes, the charged particles involved in solar storms take longer to traverse the vast distance of space between the Sun and Earth.
*downvoters be like “oh no, it answered the question successfully, how can I get triggered emotionally by this?!” Like seriously guys you realize it’s basically a calculator for language? what the fuck are you hating on?
I would surmise they're talking about a system to let us know where the worst effects are happening so people can prepare. This article says the fastest storms take 15-18 hours to arrive and most are slower. https://www.swpc.noaa.gov/phenomena/coronal-mass-ejections
So, the thing is we can't really predict CMEs. What we can do is observing them by satellites like SOHO or SDO (actually you can also check these data, check for jHelioViewer). While light indeed needs roughly 8 minutes to travel from the Sun, the ejected plasma is much slower than that, it travels at a comfy pace of 1000km/s or so. So it takes about a day to reach Earth (you can do the precise numbers as a homework or use Wolfram alpha to cheat), so from the observations we have roughly this time to do anything.