The term 'Tornado Warning' is a warning issued by the National Weather Service when a tornado has been sighted or indicated by weather radar. The warning includes the location of the storm and the potential danger it poses. The term 'SIREN' is a five-letter word that is often associated with tornado warnings, as sirens are used to alert people in the area of an impending tornado. Sirens are typically loud, high-pitched alarms that can be heard from a distance, and they are used to warn people to take shelter immediately.