The outdoor sirens wail, visions of tornadoes swirl, and people scurry indoors.

But in Dakota County, there's a catch: The sirens blare for not only twisters but also for severe thunderstorm warnings.

"We're a little bit of a maverick," said Dave Gisch, Dakota County's emergency preparedness coordinator. "We feel that if you look at what's happened historically in Minnesota and the metro region, there have been severe thunderstorms and from those severe thunderstorms have come tornadoes."

The decision to turn on the outdoor warning sirens is a local one, and most counties, including Hennepin and Ramsey, prefer to save the system for times when the National Weather Service issues a tornado warning or predicts winds in excess of 75 miles per hour. But Dakota has followed the tornadoes-and-thunderstorms siren policy for decades.

Sirens blared in cities across the metro last weekend when severe weather rolled through, knocking down trees, dousing the area with rain and prompting flash floods. In communities struck by disaster, as Wadena was when a tornado ripped through on June 17, officials and residents alike note that outdoor warning sirens save lives.

Some wonder, though, if turning on the sirens too often desensitizes residents, who might start to take the warnings less seriously.

"We feel like it might be so often that people might get cry-wolf syndrome," said Deb Paige, emergency management director for Washington County.

"There are a lot of thunderstorm warnings, and although thunderstorm warnings are a safety issue, we agree with most of the rest of the state in the fact that setting off outdoor warning for thunderstorm warnings is inappropriate," said John Tonding, communications manager for Anoka County.

It took some getting used to, but Dakota County resident Judy Turnbull, who lives in Burnsville, said she is glad for the extra siren warnings.

"It is helpful," she said, noting that a strong storm is enough to knock around patio furniture and blow down tree branches. "Originally, I thought it was just for tornadoes, but I appreciate it."

Angela College of Robbinsdale ushered her family into the basement after hearing a siren on Saturday night.

She said that she was accustomed to hearing sirens more often, and reacting with less urgency, while growing up in Burnsville.

In Robbinsdale, which is in Hennepin County, "if they go off, you know there's severe weather. It means business."

That's the reason many counties save the sirens for tornadoes.

Joey White heard the sirens at his Burnsville home Saturday night. He pulled up the radar on his cell phone, and seeing no impending danger, wondered why the siren sounded.

"It seemed a little odd to me," he said. "The expectation with most communities is that the siren means tornado."

Yet White's reaction is exactly what Gisch and other emergency officials hope for -- a pause, a search for more information, and if conditions warrant it, a move toward emergency shelter.

"We have citizens that say [we're] crying wolf," Gisch said. "Our response is, we would rather warn you that there's a storm warning and it's up to you to decide what you want to do."

Katie Humphrey • 952-882-9056