Computer delay led to sounding all tornado sirens, official says (VIDEO)

An unexpected delay in data collection by Sedgwick County’s upgraded outdoor warning system prompted officials to sound every siren in the county as a precaution Wednesday night, even though Wichita was never threatened by tornadoes.

The county’s outdoor warning siren system was upgraded to allow for targeted activation in 2012, but quiet tornado seasons in the Wichita area the past few years meant Wednesday night was the first time the full system was in use for a live storm event, interim emergency management director John Crosby said.

“The good news is the overall system did work last night,” Crosby said.

The bad news, though, is when a tornado warning for portions of western Sedgwick County was issued by the National Weather Service, “there seemed to be some kind of delay” in the siren system’s collection of data from the agency’s warning bulletin, Crosby said.

The weather service warnings always include the latitude and longitude for the geographic area covered. The siren system’s computer is designed to scan for and read those coordinates, plot them on a map and then activate the sirens within the warning polygon.

But that wasn’t happening, Crosby said, and officials grew so uncomfortable with the delay that they sounded every siren in the county just to be safe. Officials didn’t want the delay “to put people in harm’s way,” he said.

“I don’t know the exact cause of the delay to get the information into our system,” Crosby said. “Our system did eventually get the warnings and plot the polygons.”

Once that happened, sirens outside the polygons were shut off.

“We know the system will work,” Crosby said. “What we need to do is find out what the delay was.”

Brief tornadoes

The Wichita metropolitan area saw a handful of tornadoes Wednesday night during what one official described as the most active severe weather day of the year.

None of the short-lived tornadoes caused any damage, National Weather Service meteorologist Vanessa Pearce said. All were rope-shaped tornadoes west or southwest of Wichita in western Sedgwick and Kingman counties.

Wichita was spared tornadoes and hail from the severe storms — and nearly missed out on rain altogether. Just .02 of an inch fell from the storms that rolled over the city Wednesday night.

“The conditions were pretty good yesterday for storm development,” Pearce said. “We did have storms.”

They just weren’t as intense as some weather agencies predicted.

As it turned out, Pearce said, there wasn’t enough instability in the atmosphere to trigger large, long-track tornadoes. While a couple of tornadoes touched down “pretty close” to Wichita, she said, the city was never under the threat of a tornado.

Ten tornadoes were reported across the country Wednesday, eight of them in Kansas. Two tornadoes were confirmed in central Kansas, in Barber and Comanche counties, according to Larry Ruthi, meteorologist in charge of the Dodge City branch of the weather service.

They were among 300 severe weather reports logged on Wednesday, which is the most on one day so far this year, Greg Carbin, warning coordination meteorologist for the Storm Prediction Center in Norman, Okla., said via Twitter.

Those numbers are preliminary, however, and may change upon closer review. It’s not unusual, for instance, for the same tornado to result in multiple reports from different locations.

The Wichita branch of the National Weather Service did not plan to send out any damage survey teams because no damage has been reported, Pearce said.

More thunderstorms are possible this weekend in south-central Kansas, she said, but they are not expected to have the capacity to produce tornadoes.

Oaklawn tornado predated upgrade

The outdoor siren system was in the midst of the software upgrade when a tornado struck Oaklawn and south Wichita in April 2012, said Crosby, of Sedgwick County emergency management. The upgrade included folding all sirens in Sedgwick County suburbs into the warning system.

Eventually, Crosby said, all sirens in the system will be able to be heard outdoors about a mile away. Some of the 147 sirens now in use only have a half-mile radius.

A siren in Goddard was destroyed by the high winds of a bow echo thunderstorm that raced through the area on April 3. It has not yet been replaced.

Some of the sirens still in use are 60 years old, Crosby said. Five are being replaced this year as part of a capital improvement project.

The sirens are only intended to warn people who are outside, such as at the zoo or a ballfield or a park.

“I wouldn’t rely on the outdoor sirens as the sole source of warning in any instance,” he said.

People indoors should rely on any of several other ways to receive weather warnings, Crosby said: television, the Internet, weather radios or smartphones.

“I cannot attest to every square inch of Sedgwick County as to whether you’ll hear the siren,” he said.

This story was originally published April 9, 2015 at 9:12 AM with the headline "Computer delay led to sounding all tornado sirens, official says (VIDEO)."