Pretty cool, but how does it work?

As you twist the jar, the soap-water-vinegar mixture that's against the glass interior of the jar bumps up against the inside of the jar and is pulled along in the same direction, due to friction. The fluid further inside the jar takes longer to get moving, but eventually the energy you're applying makes it spin in the same direction as the jar as well. When you stop spinning the jar, the fluid inside it keeps spinning. A miniature tornado twister will appear for a few seconds as the energy you've applied makes a vortex rise in the jar, in the same way a vortex of air rises inside a storm cloud.

Tornado Safety Tips

Here's some reliable advice from NOAA on how to stay safe during a tornado: You should go to an underground shelter, such as a basement. But if you don't have a basement, move to an interior room or hallway on the lowest floor and get under a sturdy piece of furniture. A powerful tornado can last from 20 minutes to more than an hour, so don't come out of your shelter until you're sure the storm has passed. Do not try to outrun a tornado in your car, and stay away from mobile homes, which are easily uprooted by tornadoes' powerful winds, even if they're tied down. It's a good idea to talk to your family about making an emergency plan for what to do in the event of a tornado (or a fire, or another disaster). That way, if a tornado strikes, you'll know exactly what to do to stay safe, and how to reunite with family members afterward.