Just to add:
Tornado Watch - Conditions are favorable for a tornado to form
Tornado Warning - A tornado has formed / been spotted/confirmed
It's confusing lingo because you could reverse the two and it still makes sense. NOAA was looking at changing it a few years back but I don't think anything ever happened with it.
Another thing that has happened over the decades is the weather reporters' hyper sensitivity to meteorological events which leads to it being a "boy crying wolf"-problem. For either ratings or legal reasons what would have just been considered a regular "storm" 40-50 years back is now reported as a major event and usually classified as a "severe storm".
For example, most people understand clouds and rain in the forecast. I'd argue that people understand "storm" meaning lightning and thunder and "severe storm" meaning it's going to get nasty with a lot of lightning, thunder, hail, and wind. I swear that anytime they see even a few strikes of lightning these days it's reported as a "severe storm". When people see "severe storms" hit again and again without being all that severe (really just regular storms) they let their guard down so the forecasters really don't have anywhere to go with their reporting and, I think, it leads to a more dangerous situation.
They dilute their message by either sensationalizing regular storms for ratings or by being overly cautious because they fear they may be wrong one day.