A
tornado warning (
SAME code: TOR) is an alert issued by national weather forecasting agencies to warn the public that
severe thunderstorms with
tornadoes are imminent or occurring. It can be issued after a tornado or
funnel cloud has been spotted by the public,
storm chasers,
emergency management or
law enforcement, or more commonly if there are
radar indications of tornado formation. When this happens, the
tornado sirens may sound in that area if any sirens are present, informing people that a tornado has been sighted or is forming nearby (because sirens are not intended to be heard indoors, residents should not completely depend on them. Have more than one way to receive alerts). The issuance of a tornado warning indicates that residents should take immediate safety precautions. It is a higher level of alert than a
tornado watch, but (in the United States) it can be surpassed by an even higher alert known as a
tornado emergency.