Chris Dolce
All tornado warnings should be taken seriously, but there are actually key details that differentiate them and can give you more helpful information about the rapidly-evolving situation.
A tornado warning is issued by the National Weather Service (NWS) when a tornado has been sighted and/or indicated by radar. You should always seek shelter if one is issued for your area.
What you might not have noticed before is that there is information in a tornado warning that communicates the specific reason it was issued. Below we break down the terminology you should look for and what it means.
Example of a supercell thunderstorm on radar with a tornado warning (red polygon).Radar Indicated
Most tornado warnings cite "radar indicated rotation" as the reason the warning was issued.
That means a severe thunderstorm is exhibiting signs of strong rotation on Doppler radar, which indicates that a tornado could be in progress or that one could form at any time.
When "radar indicated rotation" is cited in the warning, it's not yet known if an actual tornado is in progress, but the NWS forecaster wants to provide as much lead time as possible before a tornado occurs to keep you safe.
Radar Confirmed
Occasionally, you might see another type of tornado warning that indicates there is a "radar confirmed tornado". This means Doppler radar is showing signs that debris has been lofted into the air near the area of low-level rotation in a storm, giving the NWS high confidence a tornado is in progress.
The upgrade of National Weather Service radars to dual-pol technology in the past decade has greatly aided the ability of meteorologists to see when a tornado has likely sent debris flying into the air.
Top: A radar-indicated tornado warning. Bottom: A radar-confirmed tornado warning.Spotter Confirmed
On rarer occasions, you will see "confirmed tornado from trained spotters" as the source cited in a tornado warning.
That means a tornado has been spotted by a trained spotter and/or law enforcement.
Sometimes this spotter confirmation of a tornado might come in an update to an existing tornado warning.
For example, the tornado warning might have first been issued based on radar alone. Shortly thereafter, the National Weather Service (NWS) might receive credible information that a tornado has been sighted. The NWS can then update the messaging in that warning to say it's spotter confirmed.
Tornado Emergency
A tornado warning that carries with it a "tornado emergency" is the rarest and is reserved for the direst of situations.
This is only issued "when there is a severe threat to human life and catastrophic damage from an imminent or ongoing tornado", the NWS says.
The tornado emergency can be issued based on a confirmed sighting of a tornado or one that has been confirmed by radar.
Below is an example of a tornado emergency the NWS declared for Fort Polk, Louisiana, on April 22, 2020. This particular tornado emergency was issued based on radar confirmation that debris was being lofted by a dangerous tornado.
An example of a tornado emergency issued for Fort Polk, Louisiana, on April 22, 2020.The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.
The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.
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