Weather warnings can save lives. Here’s what makes it effective.

Severe weather can happen any day of the year. If you’re in its path, you’ll likely get a warning in the form of a blaring alarm on your mobile phone or a text scrolling across your TV screen.

These messages are carefully designed to make sure you have time to seek shelter before it is too late, which could unnecessarily put you or emergency medical personnel in danger.

But what makes people heed these warnings?

It’s something scientists are learning more about every day. Here’s how it works and how you can convince your uncle, for example, that he really needs to evacuate before the next hurricane.

The effective warning is specific.

Kathleen Sherman Morris, a professor of meteorology and climatology at Mississippi State University, said people often look for an indicator that they will be directly affected by a storm. That means it’s important for the warning to be more specific than, say, saying a tornado is headed toward east Tennessee.

“Very often you’ll hear people on TV pointing out communities, roads and landmarks,” Professor Sherman Morris said. “These kinds of things are very important to help people understand that it is getting close to them.”

If you’re trying to convince a skeptical relative about an upcoming danger, it’s helpful to be specific in your message as well (assuming they trust you). Tell them about a local landmark that could be affected, based on the forecast, or when the storm is expected to be at its worst where they live. If you know someone in the area who has already encountered problems due to the storm or posted information about its destruction online, it may also be helpful to pass on this information.

Why do some people hesitate or ignore warnings?

Some people will go to a tornado shelter as soon as a warning is issued. Others may receive the warning, then take a few minutes to read about the storm online, watch what TV is saying and talk with family and friends before taking shelter. “Different people need different levels of assurance,” Professor Sherman Morris said.

Those who do not act because they think they will be fine, despite warnings, are in the minority.

To emphasize potential danger, emergency managers sometimes use shocking or contradictory language, said Amber Silver, an assistant professor in the Department of Emergency Management and Homeland Security at the University at Albany.

In 2017, Patrick Rios, then the mayor of Rockport, Texas, told people who chose not to evacuate before Hurricane Harvey to use a permanent marker to write their names and Social Security numbers on their arms in the event of their death.

Alerts do not reach everyone

The National Weather Service provides alerts in English and Spanish, which may limit communications with people who primarily speak other languages.

In September 2021, torrential flooding in New York City highlighted the challenges faced by people who are not fluent in English. Many of the thirteen New York City residents who died spoke limited English and may not have received or understood warnings sent before the storm.

Messages can also be incomprehensible to people with cognitive problems, or inaccessible to those who cannot afford computers or televisions.

Specialized alerting equipment exists for people who are blind, deaf or hard of hearing, but more common information sources, such as television broadcasts, can also be made accessible using more descriptive and specific information, according to a 2020 study in the International Journal of Disaster Risk Reduction.

That’s why a key part of the warning process is family, friends and community, not just technology, said Kim Kloko-McLean, a senior sociologist with the National Weather Service, who visits places that have seen extreme weather events. Residents on how warnings affect their behaviour. Good alert systems involve “a group of organizations of people who all come together to alert each other that something is happening,” she said.

It’s not always easy to leave.

Once people get a warning, it can still be difficult for them to act on it.

First, shelter is not a given. People living in mobile homes, which are not usually considered safe shelter in severe weather, should decide to find a safe place before a warning is issued, because travel can quickly become dangerous. Not everyone has a social network that can help them find a safe place.

People who need to evacuate their homes but have mobility challenges also face barriers in responding to alerts. A 2002 study in the journal Natural Hazards Review found that households with people with mobility challenges were less likely to be evicted than those without.

For others, transportation, food, and hotels during an evacuation can be expensive.

Ms. Kloko-McLean said the National Weather Service and its parent agency, the National Oceanic and Atmospheric Administration, are working to improve how underserved populations get information in emergency situations. The agency’s VORTEX program conducts field research and collects data to give meteorologists in the Southeast more time to identify tornadoes embedded in a line of storms, and perhaps buy time to issue alerts and circulate other practical information, such as the locations of shelters.

Ms Cloco-McLean said people with fewer resources often “bear the burden” and account for a disproportionate proportion of deaths.

How can I get a severe weather warning?

Warnings may be issued for events including dangerous cold, heat, wind and rain.

Some alerts, such as tornado warnings, require immediate action. Other watches, such as hurricane watches, indicate that you should be prepared in case things escalate.

Get alerts from at least two places.

Before a storm hits, people should check to see if they can receive alerts from two sources, such as a cell phone and radio. Your mobile phone should automatically receive severe weather warnings. Many cities and states also have their own cell phone alert systems.

Professor Sherman Morris said local meteorologists can also be a great resource because they are familiar with the community.

How can alerts be improved?

The Met Service’s Ms Kloko-McLean is pushing for technology that can better address the gray area between monitoring and warning, so people can make the best decisions possible under the circumstances.

“It’s actually mind-boggling how much we can get from supermodels now,” she said. “The challenge is giving you the right slices of all of that to understand what’s going on.”

The weather service is also trying to figure out how to best get messages out to communities, such as those where English is not the dominant language. This means identifying the people and resources the community turns to for its information.

Ten years from now, the way we receive alerts may look “very different,” Kloko-McLean said.

“That’s our hope, is that it will happen.”