Severe Weather Watcher Handbook

PREV  NEXT

DON'T GET FOOLED!

One of the great joys of cloudwatching is the variety of ways Mother Nature presents Her evidence - proving or disproving our theories and assumptions about what we see. The weather watcher is constantly challenged by new circumstances and every storm adds to your understanding and respect for the complexities of the atmosphere. What we take for granted confounds us; what we perceive as obvious hides the truth eloquently; what we see and appreciate for its simple beauty speaks quiet volumes of wisdom. As your experience grows, the context for tour understanding widens until surprises enrich rather than confuse your knowledge of the sky.

False funnels

There are several tornado/funnel look-alikes which can easily fool you at first glance. Disqualifying such "false funnels "is very important for minimizing erroneous reports as well as reducing your anxiety while storm spotting.

Scud tags and inflow tails

Whenever you have air rising rapidly at the edge of cool, moist outflow, lower cloud fragments (scud) will form in mid-air or under the base in the shape of small points, lumps, etc. protruding downward. These scud tags change shape constantly and do occasionally take the form of a tapered cloud that looks like a funnel. They are most common along the gust front, near ragged lowerings, or along any cool-warm boundary. They are best differentiated from true funnels by location, since a true wall cloud is absent or found elsewhere in the sky. However, they are also less smooth-edged, more transient, more ragged or fragmented, and rising rather than rotating.

A more organized structure that sometimes appears when a new,intense updraft forms adjacent to rain or outflow, is an inflow tail. This is a low, often ragged, and thick cloud extending down at an angle below the main cloud base. It is a brief event but can be quite frightening if close by. Again, location and the absence of a wall cloud will disqualify this cloud as a tornado threat. The edges of wall clouds or lowerings also assume pointed shapes briefly, but without classic, persistent funnel features. When a tail cloud forms on the rainy side of the wall cloud, however, it may indicate overall intensification and the entire structure should be watched.

124  W/NE,  125  E/E,  126  NW/NE,   127  SE/S,  128  SW/SE,  129  N/E   Examples of false funnels. All of these are scud rising in updrafts that have drawn some of the moist air in from nearby outflow. In 127 and 129, the updraft is under the rain-free base and shows you where the next, strong tower may be along the axis. All examples are transient, having a funnel-like shape for only seconds before becoming less deceiving.

PREV  TOP  NEXT

The Green Lane^TM,
Environment Canada's World Wide Web Site.