Beginning this fall, the National Weather Service will begin using a more precise weather warning system to give people a better idea of the location of short-lived, dangerous weather events, according to the weather service.
Currently, most warnings for tornadoes, severe thunderstorms and flash floods are issued on a whole-county basis, but problems with this system can arise when entire counties are put on alert when only a small portion of the county is affected.
During the past couple of years, the weather service has tried to specify the part of a county in the path of a severe storm such as issuing warnings for the northern or southern half. The new system will be even more precise, said Jim Kramper, warning coordination meteorologist for the weather service in St. Louis.
“It’s about trying to get it as specific as possible,” Kramper said.
Visually, the new warning system will show a polygon shape to indicate the short-term path of a severe storm without regard to county boundaries. “We see where the storm is, we project its path and pick an area we want to warn,” Kramper said.
The new warning system will become mandatory for all National Weather Service stations on Oct. 1.
Patrick Market, MU assistant professor of atmospheric science, thinks the new system will improve people’s confidence in the warning system.
“When you issue a tornado warning for an entire county, and there’s not a cloud in the sky in the southern part, it gives the perception that the weather service doesn’t know what they are doing,” Market said.
Schools and other large institutions that have plans for taking shelter when severe weather threatens may also benefit from the more specific warnings.
“We’re connected to the emergency broadcast system, and when the radios go off for a tornado warning for the county, we take cover,” said Lynn Barnett, assistant superintendent of Columbia Public Schools. “It will help them know better when to tell us to take cover.”
The school district, however, doesn’t plan on splitting hairs for warnings that affect Columbia, Barnett said.
“If it’s going to be anywhere near Columbia, we won’t just tell one part of the school district to take cover and the other to not,” she said. “I don’t think we will ever be that specific.”
Kramper said the weather service in St. Louis has had the capability of creating storm-based warnings in the polygon shape for years, but they are now asking outlets who give warnings to the public to display the actual warning area.
Typically, television stations put a small graphic at the bottom of the screen to show which counties are included in the warning or watch, Kramper said. But because it is so small, it might be difficult to display the polygon area.
Changing the way these warnings are broadcast on running scrolls at the bottom of a television screen or on radio will also be a challenge, Kramper said.
“In words, it’s hard to pinpoint what the warning is for,” Kramper said.