From satellites in space to radar in Atlanta, emergency responders keep their eyes on the skies in an ever-present watch for tornadoes.
While the storms will always be a threat in North Georgia, the technological leaps made since the vicious 1998 storm claimed 13 lives in the area sound like science fiction. But despite advances in technology, unusual storms like the 1998 tornado remain difficult to detect.
Weather trackers can scan not just for storms forming in the atmosphere — and much earlier than they could 20 years ago — but they can track any debris in the atmosphere in real time.
“Once tornado debris is detected, we can issue warnings with greater certainty that a tornado is on the ground doing damage,” said Steven Nelson, science and operations officer for the National Weather Service in Peachtree City.
Before 2007, it took six minutes to determine whether a tornado was forming in the area. It now takes 90 seconds. Radar in Atlanta is now able to detect smaller tornadoes with upgrades to the technology in 2004, 2007 and 2012.
The Severe Storms Research Institute at Georgia Tech is working on technology to track lightning strikes in real time and detect clusters of strikes that could warn of an imminent tornado.
Two new weather satellites were launched in November 2016 and February 2018 that “provide round-the-clock observations of the western hemisphere with twice the resolution and four times the sensitivity of previous NOAA satellites,” Nelson said. “The time delay to receive the imagery also dropped from 10 minutes to 2. Finally, the new satellites have a real-time lightning detection capability that was not there before.”
With 2018 technology, the National Weather Service would have had more of a chance to detect the tornado before it touched down at 6:27 a.m. March 20, 1998, on Leach Road, but it wouldn’t have been a sure thing.
The 1998 tornado was a quasi-linear convective system, which means it formed from the ground up and with little warning. Conventional tornadoes form underneath supercell thunderstorms, which are detectable by radar, satellite and the naked eye.
QLCS tornadoes can form in unexpected conditions, Nelson said, and they’re more difficult to detect with radar because they form at ground level, where radar is ineffective. Tornadoes that form from the cloud level to the ground create a rotation pattern in the atmosphere that can be monitored by both radar and satellite, he said.
But once the tornado was detected, the storm’s track would be logged by radar and satellite, and warnings would have been sent to local emergency officials and any mobile phones near the storm would receive a wireless emergency alert.
Mobile phones would also receive text and email alerts from the Hall County emergency management agency, provided they’ve signed up for the service.
Near the tornado, Hall County’s outdoor weather sirens would be screaming in 2018, where in 1998 all residents had to warn them was the freight-train sound of the coming storm. For some in the path of the storm, there was no warning at all.
But there’s no guarantee an outdoor siren would have offered much warning for people in 1998.
“People think they should hear them inside as well, but ... really outdoor warning sirens are for outdoors,” said Casey Ramsey, interim director of the emergency management agency and a captain with Hall County Fire Services. “They’re a good concept, but they have their place.”
With the tornado touching down near dawn, most people would have been still in their homes or asleep as the sirens rang.
While many people in the Southeast have some memories of hearing sirens being tested — that familiar windup to the full-blown wail one Wednesday or Saturday a month — outdoor weather sirens are already being outpaced by mobile alerts.
Hall County spend more than $500,000 each year maintaining its network of 23 sirens covering the most populated areas of Hall. By contrast, keeping up its mobile alert system costs about $70,000 each year, according to Ramsey.
The county has no existing plans to add to the siren network, instead focusing on the citizens alert system because the text and email alerts are more likely to get directly to residents to warn them of exact threats.
There are 45,000 subscribers to the service at the moment, and it can accommodate an unlimited number of subscribers.
“If all 200,000 people in the county signed up, we could do it,” Ramsey said.
Meanwhile, Fire Services has twice the number of stations that it did in 2018 and a much more advanced communication system within the department.
In Fire Services vehicles, first responders can view notes and conversations from dispatch in real time, and maps of damage or injuries can be uploaded, shared and commented on among the entire fleet responding to a storm or any other incident.
“Once we arrive and we establish a command and we assess the situation, we can enter (information) to push to every one of the computers that are online. All of the vehicles responded, we could put a map in there if we needed to,” Ramsey said. “With those computers, not only are we getting information, we can click on a map that’s in real time — it shows where our units are out ... who is our closest fire truck or closest ambulance, where they’re responding from and how long it’s going to take them to get there.”