But some technology only needs to spread to be effective. That’s certainly true for storm warnings, which now reach individual pockets and purses.
Since April 2012, the National Weather Service has been able to send alerts about weather emergencies to people with newer smartphones. (About 55 percent of Americans have smartphones, according to ComScore.) Messages can also be sent for local emergencies, AMBER alerts and presidential alerts during national emergencies.
Smartphone alerts are geographically tailored. The weather service also has devised a “polygon” warning system, tied to cell towers, to make warnings for things like tornadoes, floods and severe weather more specific than the old, county-based system.
Private companies also offer telephone-driven warning systems. For example, TechRadium’s Immediate Response Information System makes automated calls when the weather service issues alerts. In Royce City, Texas, officials are using TechRadium’s technology instead of warning sirens, which the city’s fire chief and emergency management coordinator, Richard Bell, said were more expensive and only worked for people who are outdoors.
The weather service is experimenting with social media, as well, to reach people who don’t watch weather on TV or own weather radios. In Oklahoma — where the weather service has 32,000 Facebook friends and the Twitter handle @nwsnorman has 13,500 followers — a test in March found that a Facebook message reached 200,000 people in just a few minutes.
Even those hyper-personalized alerts will not mean the end of long-time staples of weather warnings like radios and sirens. In part, that’s because cellphone networks can be overwhelmed by traffic or knocked offline in a crisis, said Kim Klockow, a Ph.D student in geography at the University of Oklahoma who is researching how people respond to tornado warnings. Klockow’s work after the 2011 tornadoes in Alabama and Joplin, Mo., confirmed earlier studies showing that people want multiple sources of information about storms. More than half of those she interviewed first learned of those tornadoes from sirens then checked other sources such as television news or their friends.