Severe Weather Watcher Handbook

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117, 118  E/SE,  119  W/E   Three examples of non-tornadic funnel clouds. 117 is a cold-air funnel dangling like a snake below a large cumulus cloud. The funnel in 118 is not connected with a lowering or updraft. Instead, it formed on the boundary between different airstreams (possibly separate outflows at the back of this sstorm) and is referred to as a "shear funnel". The needle or "spaghetti funnel" in 119 (see also photo 135) can appear briefly under intense updrafts (usually LP storms) but rarely touches down.

Other funnels

A funnel cloud is just a spinning vortex and you may see one that looks like the real thing but is either in the wrong location or eems unrelated to any lowering or updraft region. These mid-air funnels are very deceiving and the only way to discount their threat is to look at the surrounding clouds for clear signs of rotation.Fortunately they are very short-lived and quickly decay after formation.

Landspouts

The landspout is a weak tornado type seen under small storms or large, growing cumulus clouds.It is like a cold-air funnel that has touched down, and can cause brief, minor damage. Landspouts occur in most parts of Canada. They don't always have a full condensation funnel and are sometimes only made visible by the dust they stir up.

Waterspouts

The waterspout is another weak tornado type. Like a landspout, it looks like a slender tornado but occurs only over water in the same situations as cold-air funnels. They are occasionally seen near the coasts in the late summer and fall, but are more common in early fall over the Great Lakes and other large lakes.Cool, unstable air masses passing over the warmer waters allow vigorous updrafts to form,which can tighten up into a spinning column. The cool, moist air supports a full condensation funnel despite the weaker rotation. Waterspouts can be dangerous for boaters and shoreline locations but are no threat farther inland since they collapse as soon as they move onshore. A true waterspout forms over the water and is not accompanied by a strong storm. If a severe storm with a tornado happens to pass over a stretch of water, the tornado is sometimes called a tornadic waterspout and would be just as dangerous as if it were over land. The difference is entirely in the weather we see with the waterspout. If it's cool, cloudy, with showers around but no organized storms, then the appearance of a tornado-like funnel over water will be a regular waterspout.

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