How do tornadoes and waterspouts form?


Top Answer
User Avatar
Wiki User
2011-12-05 16:46:13
2011-12-05 16:46:13

The formation of ordinary tornadoes is complicated.

First, a condition called wind shear, in which the speed or direction of the wind changes with altitude. If the shear is strong enough it can essentially tilt a thunderstorm, this separates the updraft and downdraft of the thunderstorm, preventing them from interfering with one another. This allows the storm to become stronger and last longer.

Additionally, if the wind shear is strong enough it can start the air rolling in what is called horizontal vorticity. This horizontal vorticity can then be turned vertical by a thunderstorm's updraft. When this happens, the thunderstorm may start rotating. The rotation is especially strong in an updraft called a mesocyclone. If the storm intensifies rapidly enough, a relatively warm downdraft called a rear-flank downdraft or RFD can wrap around the bottom part of the mesocyclone. This can then tighten and intensify its rotation and bring it down to the ground to produce a tornado.

There are two types of waterspout. First there are tornadic or type 1 waterspouts. These are ordinary tornadoes that happen to be on water, and form by the mechanism detailed above.

More common atre type 2 or fair weather waterspouts. These are weaker than regular tornadoes and can form from an ordinary thunderstorm, or even a towering cumulus cloud. Both thunderstorms and cumulus cloud generate an updraft. If they occur over a relatively warm body of water the updraft at the surface can be strengthened. If there is any hint of rotation in the air, which can occur on its own, it can get caught up in the updraft, tightened, and intensified to produce a waterspout. This mode of formation is more like that of dust devils than it is of tornadoes.


Related Questions

User Avatar

Tornadoes usually form on land, but they can form on water in which case they are called waterspouts.

User Avatar

Some tornadoes form as waterspouts and then move on to land, but not usually.

User Avatar

Tornadoes or twisters usually form over land. But sometimes they form over water as waterspouts.

User Avatar

Tornadoes usually form on land, but they can form on water too. In that case they are called waterspouts.

User Avatar

Not usually. Most tornadoes form over land. Occasionally they form over water and are called waterspouts.

Copyright © 2020 Multiply Media, LLC. All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply.