Tornado Warning
In short
A tornado warning is an urgent alert issued when a tornado is actually occurring or is imminent due to radar detection or visual sightings. It tells people in a specific area that they must take immediate cover to stay safe.
In plain words
This is a high-level emergency notice. It means a tornado has been spotted or radar shows a storm is about to produce one. You should move to a basement or an interior room right away.
A simple example
A weather service issues a warning for a specific county because radar shows a rotating storm cloud moving towards a town. Residents in that county immediately head to their storm shelters.
Why it matters
These warnings provide the vital minutes needed to find shelter before a destructive windstorm hits. Following a warning can prevent serious injury or death from flying debris.
Easy to mix up
Do not confuse this with a tornado watch, which only means conditions are favourable for a tornado to form.