This IS a Drill: Tornado Sirens to Blare at 1:25

The National Weather Service plans to issue a mock tornado watch early Thursday afternoon.  Locally the watch will be posted around 1:20.  At 1:25 a tornado warning will then be issued, which will also use the city's tornado sirens.

So the answer will be "no, there isn't a tornado - it's only a drill."

The drill is meant to test communication systems for watches and warnings and will last about an hour.  Emergency officials say the drill also provides schools, families and businesses an opportunity to practice their response.