You mean in your daily in-take of media? Local TV stations are required to broadcast weather. It's actually part of their licensing. So if you're not in the habit of turning on the local station because of crappy programming (like me), then you should at least be willing to find a local station during weather. Even if regular programming is on, they will break in when requested by the NWS. Local radio will as well, but I can't remember the last time I heard Clearcom or whatever the othe station owner is do this. I just don't listen to radio.
Also, most local stations will also be running live webcasts to FB/YT/etc. They do this in order to avoid interrupting programming until it is urgent enough to do so.
I'm in North Texas, and during severe weather season, I have a web browser permantely tuned to the radar. If it's getting bad, I'll find a local station.
> I imagine if nuclear armageddon ever happens, it'll be similar
If you're in Hawaii, you'll get a text.