Science Question

[Rich Long]

We had a funnel cloud pass very close to our community Friday and one of our residence was confused about the difference between a funnel cloud and a tornado. I told her that it's not a tornado until it comes in contact with the ground (there were no damage reports) which she understood then. Her follow up question is what I need help with "Wow interesting, so what keeps the funnel that looks to be pretty close to ground level from actually touching the ground, the circulation of the wind?"

I'm not sure we know. I do know I don't know.. any help would be appreciated!

 

[Tim Shriver]

Most of the time the "Funnels" folks see are one of two types.

1. The funnel hanging from the base of a t-storm. Most of the time these never become a tornado.

2. They see a funnel but do not see that the actual tornado is already in contact with the ground.

Remember air is clear, you cannot see a tornado until debris or rain etc. gets mixed in.

When you do see a tornado (rotation on the ground up to the base of a t-storm) and you see the funnel, that is most likely the
condensation vortex (funnel) within the tornado. The tornado is much wider/taller then this funnel or condensation vortex is.

Tornados spin up, they do not touch down for the most part thus my reasoning.

True funnels rarely become a tornado.

NWS KMKX:

Tornado: violently rotating column of air extending from the ground to the base of a convective cloud.

Hope this helps....

Tim

Tim

 

[rdale]

Mostly correct, but not sure what you mean about "true" funnels.

 

[Patrick Marsh]

Tornadoes do not "lift" or "skip" or any of those other descriptive words often used. Tornadoes are a fluid (in the physics definition of the word), therefore they "strengthen" and "weaken". In the case of mesocyclone tornadoes, what governs if they reach the ground is how fast they are spinning, given the surrounding environment. The more stable the lower-levels of the atmosphere, the strong the funnel cloud's rotation must be in order for it to reach the ground.