what's a bi-level tornado?

Answer 1

Quite frankly I have never heard of such a thing in my many years as a meteorologist. It's possible that it may be used as a description of what is called a gustnado which does show up in the Glossary of Meteorology and is described as a short-lived, shallow, generally weak tornado found along a gust front. Gustnadoes are usually visualized by a rotating dust or debris cloud. This particular type of tornado is not created like the much more common variety which we see descending from the base of a cumulonimbus cloud. It may be overcast or possibly even clear when a gustnado is observed. But what I'm thinking is that its possible that both types might have been observed at the same time giving rise to the term "bi-level" tornado. This, of course, is just my hypothesis. Sorry I can't offer more.

Answer 2

a tornado that has 2 levels