RECENT LOCATIONS

Close
Add a location
Edit your saved locations

Untwisting the truth behind a waterspout


This is an example of a waterspout formation sent in by TWN viewer Scott Taylor; shot August 10, 2011 in Port Colborne, Ontario.
This is an example of a waterspout formation sent in by TWN viewer Scott Taylor; shot August 10, 2011 in Port Colborne, Ontario.

Staff writers

August 10, 2012 — It is your typical stormy summer day: rain, lightning, strong winds -- until you are stopped in your tracks at what looks to be a tornado over the lake...but is it?

Waterspouts come in a variety of sizes and strengths and arise from different mechanisms.
Waterspouts come in a variety of sizes and strengths and arise from different mechanisms.

Though it is usually not as destructive as its land counterpart -- the tornado -- a waterspout can often be confused as such. 

Waterspouts are similar to tornadoes but it is the manner in which they form that truly separates the two weather phenomenons. Generally waterspouts are given the name "tornado over water" and is not given the name of a real twister until they reach land. 

The way they move is also similar in that they spin up as they move up the surface boundary from the horizontal shear near the surface. This motion is followed by an upward stretch to the cloud once the low level shear vortex aligns with a developing cloud or thunderstorm. Weak tornadoes, known as landspouts, have been shown to develop in a similar fashion.  

While some waterspouts are strong and tornadic in nature, most are much weaker and caused by different atmospheric dynamics.

While many waterspouts form in the tropics, locations at higher latitude within temperate zones, such as the Great Lakes, also report waterspouts

Types of Waterspouts:

Tornadic:

Also known as "tornadoes over water". They form in a manner essentially identical to land-based tornadoes, but simply occuring over water. This type of waterspout can start as a tornado over land, and is subsequently classified as tornadic once it moves over a body of water. Tornadic waterspouts can be fairly destructive. 

Non-tornadic:

Non-tornadic or "fair weather" waterspouts are not associated with a rotating updraft of a supercell thunderstorm. These are by far the most common types and are generally not as dangerous as tornadic waterspouts. 

Winter Waterspout:

Can also be referred to as a snow devil, an icespout, ice devil, snonado, or a snowspout. This is an extremely rare instance of a waterspout forming under the base of a snow squall. The term "winter waterspout" is used to differentiate between the common warm season waterspout and this rare winter season occurrence. 

Intrigued by waterspouts and other remarkable weather wonders? Be sure to view this video as Chris St. Clair explains everything you need to know about weather -- from the formation of tornadoes to the meaning of wind chill. 

Log in or Sign up to submit a comment.




Comments





Take your weather with you, no matter where you go.

Get instant forecasts and alerts, right on your computer.

  • RSS & Data
Add weather updates to your website or RSS reader.