COLUMBIA — On Friday night, tornado sirens could be heard far and wide in Columbia, even though no warning had been issued for the city.
Friday's warning was intended for Ashland, 12 miles south of Columbia.
The reason for the siren in Columbia: Whenever a tornado warning is issued in Boone County, every siren in the county is sounded.
Zim Schwartze, director of the Columbia/Boone County Office of Emergency Management, said the all-county alert is based on the unpredictable nature of tornadoes.
The Emergency Management Office initially had multiple sirens for different sections of the county, Schwartze said.
"It caused a lot of confusion because people could kind of hear the siren and not know where it was coming from," she said.
Last year, the office decided to sound the sirens for any threat in Boone County.
Schwartze said every county in Missouri has a different policy for activating the tornado siren, based on the size, shape and population of the county.
Because the majority of residents in Boone County live in Columbia, Schwartze said it is vital to warn them about any dangerous conditions around them.
"The weather in Missouri is unpredictable," she said. "We saw that in the storm that happened on March 4."
That day, a tornado warning was issued in the northwest part of the county, and soon afterward, another was directed to the southwest portion. That reinforced her thought that an all-points alert was more effective than separate warnings.
"It's important to let all the residents of Boone County know when there is a tornado warning in the area because you never know what's going to happen next," she said.
Sirens are activated for tornado warnings, as well as severe thunderstorm warnings where "extensive damage is highly probable" or if sustained damaging winds of 70 mph or higher are possible, according to the Office of Emergency Management.
Additionally, the sirens will sound if extensive storm damage is occurring or funnel clouds have been sighted.
Boone County has more than 80 sirens within its boundaries, many added since 2006. Most are located in and around Columbia. Additionally, Centralia has its own sirens to activate.
The first alarm in Boone County will sound for three minutes. Sirens will only be activated again if a new threat has been received or conditions change drastically, Schwartze said. The sirens will not issue an all-clear signal at the end of a storm.
She said the sirens have already been activated twice this year, and none were heard in 2010.
Still, Schwartze said the countywide alarm is the best solution.
"I'd rather be safe than sorry," she said.