Storm chasing photographers take photos underneath a rotating supercell storm system in Maxwell, Nebraska on September 3, 2016. Although multiple tornado warnings were issued throughout the area, no funnel cloud touched down. / AFP / Josh Edelson / XGTY
The difference between a tornado watch and a warning
00:59 - Source: CNN

Editor’s Note: If you are in an area under a tornado warning or a tornado emergency, seek shelter immediately. Warnings can be issued with only a few minutes to prepare. Take them seriously – it could save your life.

CNN  — 

Tornadoes are among the most destructive forces in nature. They can level well-built structures, uproot trees, toss semitrailers – and kill.

Tornadoes are most common in the US Plains and Southeast but have been reported in all 50 states. They can happen during the day or at night and in any month, with peak activity in May and June in the southern Plains, June and July in the northern Plains and upper Midwest, and earlier in the spring and in the fall in the Southeast.

Knowing the difference between a tornado watch, a tornado warning and a tornado emergency could mean the difference between life and death.

To make sure you get these critical messages, you can enable smartphone wireless emergency alerts or weather app notifications, get a separate weather radio that will wake you up and work if power fails, and monitor local news reports.

Here’s what each tornado alert means:

Tornado watch

A tornado watch means conditions are favorable for tornadoes to develop. It does not mean there is a tornado.

“This highlights an area and usually alerts for the next four to six hours where risk is increasing,” said Bill Bunting, chief of forecast operations at the Storm Prediction Center, which issues tornado alerts as part of the National Oceanic and Atmospheric Administration’s National Weather Service and the National Centers for Environmental Prediction.

The message is: Be on watch in case storms strengthen. Be alert. Stay informed about the weather in your area in case conditions intensify.

You should: Have your supplies ready. Choose a safe place to shelter, if necessary. And have a plan to get there – in case a tornado develops.

Tornado warning

A tornado warning means a tornado has been spotted or there is a strong indication on radar a tornado is in progress.

“When a particular area (is) under an immediate risk, then the local National Weather Service office will issue a warning, and that’s the call to action,” Bunting said.

The message is: A tornado is imminent or underway. Seek shelter immediately.

You should: Get to your safe place until the tornado threat has passed.

Tornado emergency

This alert trumps them all: A tornado emergency means a tornado is happening now. It is the highest level and most serious of any tornado alert – basically a tornado warning on steroids.

The message is: A tornado is hitting now and will have a significant impact on human life, with catastrophic destruction to property.

You should: Get to your safe place immediately until the tornado threat has passed.

“Oftentimes, the minutes you save by getting into a safe place can make the difference in life and death,” Bunting said.

The tornado emergency, issued by local National Weather Service offices, was added in 1999 after the Moore, Oklahoma tornado, a vicious EF5 that killed dozens of people and packed the strongest winds ever recorded on the planet at 301 mph.

“It was an idea that came to the staff during a critical moment when a violent tornado moved into an area,” Bunting said.

The tornado emergency was designed to remove confusion between the other categories.

How to prep a safe room for tornadoes

Never wait for a tornado emergency – or a tornado warning or a tornado watch – to be issued to take action, the Storm Prediction Center urges. Take every storm seriously, knowing storms can change intensity quickly.

This guidance is especially true for someone who has recently moved from a place that doesn’t experience many tornadoes.

Key to a safety plan is designating a small interior room or closet on the lowest level of your home as your tornado safe place. The room should have:

• No windows and be away from exterior walls,

• A flashlight,

• A way to receive alerts while in the room, often a smartphone or weather radio,

• A helmet and shoes for every family member.

“When a warning is issued is not the time to think about a safety plan,” Bunting said. “Put that in (place) now so you know what to do when a warning is issued.”

How to keep alert levels straight

Tornadoes kill an average 75 to 80 people in the US every year, and without alerts, the number could be much greater, Bunting said.

While a tornado emergency might be simplest to remember, watches and warnings can be easy to confuse.

Here’s a light-hearted way to help keep tornado watches and tornado warnings straight:

And here’s another more straightforward explanation: