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?

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.

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.

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

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

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.