On Dec. 26, sirens rang out across North Texas, warning of the dozen tornadoes that would soon touch down. Sirens like those actually fire off less frequently than they did even a few years ago, thanks to advancements in radar technology.
And that's made a big difference, according to reporter Kim Cross, who covered the tornado outbreak five years ago that killed more than 300 people in the Deep South. On Thursday's "Think," she explained how fewer false alarms have made Tornado Alley safer.
The National Weather Service's false alarm rate for tornado sirens was 80 percent in Alabama and nationwide at the time of those 2011 storms, Cross said. Residents heard the sirens go off every few days and began to disregard them. Now, she said, that rate is closer to 40 percent.
"It was really important for the weather community to get that [rate] down so now when there is a warning people don't feel like they're crying wolf -- people are encouraged to act and get in a safe place, which really, really does make a difference," Cross said.
Months after Cross spent time in communities devastated by loss, NPR reported on an experiment by the group CASA (Collaborative Sensing of the Atmosphere) to provide an image of a storm every minute it evolved, a method far more informative that the one the National Weather Service used at the time. Now the two groups work together. CASA installed a radar in Fort Worth in November, and its data is used by the National Weather Service Forecast Office and public safety agencies.
Also: check out the historical tornado tracker map a listener asked about, which uses data from the U.S. government to show where tornadoes touched down between 1950 and 2011 and the deaths and injuries they caused: