A search team looks for possible victims from the tornado that hit Joplin, Missouri, in May of 2011.

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Five National Weather Service offices are conducting test

They are using additional wording to get people's attention

The idea is to better convey risks from significant, catastrophic storms

CNN  — 

Perhaps one of these will get your attention:

“This is a life-threatening situation.”

“You could be killed if not underground or in a tornado shelter.”

“Complete destruction of entire neighborhoods likely.”

Those terms, designed to be used when “catastrophic” tornado damage is imminent, are now at the disposal of five Midwest National Weather Service offices conducting an experiment on how to better convey risks from tornadoes and severe storms.

The “impact based” warning test, which began Monday, comes on the heels of the May 22-27 Midwest/Southeast tornado outbreak, including a tornado that killed 158 people in Joplin, Missouri.

Tuesday’s tornadoes in the Dallas-Fort Worth area are an example of conveying appropriate warnings, said Mike Hudson, a meteorologist in the weather service’s Kansas City office.

Semitrailers tossed through the air

“On days like today, we want to highlight those warnings that elicit a human response,” Hudson said.

The National Weather Service is ratcheting up its efforts to combat complacency, with the help of the scary phrases. A tornado is confirmed, on average, only once for every four formal warnings.

“We base a warning on what it can do, as opposed to what it is doing,” Hudson said. “People do personalize weather very close to their home. A storm can occur five miles away, but to them it is a non-event.”

Findings from an assessment after the 2011 Joplin tornado showed the majority of people identified local outdoor warning systems as their first source of warning. They generally would wait for confirmation from additional warning sources before seeking shelter.

“Credible extraordinary risk signals prompt people to take protective actions,” according to the weather service.

The National Weather Service will continue issuing traditional tornado warnings, but for “significant” and “catastrophic” scenarios, forecasters can add information at the bottom of the warnings issued to media outlets.

“We’ve chosen words and phrases in our warnings to really highlight those days where lives are on the line,” Hudson said.

When a storm has the potential to cause “significant” damage, meteorologists may include terms such as “major house and building damage likely,” “complete destruction possible” or “major power outages in path of tornado highly likely.”

Technology also is helping forecasters.

The National Weather Service has been changing its Doppler radars over to a dual polarimetric, or dual polarization, Doppler system. (The additional information from vertical radio waves will greatly improve many different types of forecasts and warnings for hazardous weather, the government said.)

Such radar has a better rate of detection of weaker tornadoes, helping to reduce the number of false warnings, according to CNN meteorologist Jacqui Jeras.

The five Missouri and Kansas offices in the test have the newer equipment.

“It gives us more information inside the storm that we can use to make better determinations to see if it is producing a tornado and hail,” said Hudson.

Results from the test will be analyzed in the fall, with possible application in other offices.

Hudson said the enhanced warnings are designed for the most serious storms, and will be issued in rare circumstances.

“You want to get (people) to respond in a way that will get them motivated to seek shelter.”

CNN’s Sean Morris contributed to this report.