In t his week's CoMo Explained we breakdown tornado prediction, the siren system and explain how 'Tornado Alley' works. They're quiet unobtrusive until they're not: tornado sirens . About 80 of them dot Boone County with the majority of them in a few mile radius of downtown. This week we wondered--how do those sirens get turned on? When it comes to the physical switch, the answer is easy: Columbia/Boone County Joint Communications handles that. Joint Communications is located right above the