Funnel clouds vs. Tornadoes vs. Cold air funnels

 Pictures courtesy of Robyn Bishop.

A cold air funnel was spotted by one of our viewers Robyn Bishop near Wasaga Beach around 3:30pm this afternoon.  Maybe you spotted it too and wondered "I don't hear any thunder, are there thunderstorms around?" 

I will try to make this explanation as easy as possible but it may not be that easy for everyone. 

Yes this was a "funnel cloud" but its development was not associated with a thunderstorm.  Most tornadoes begin as funnel clouds, but many funnel clouds do not make contact and are not classified as tornadoes (and not affect the ground).  Unlike typical funnel clouds which develop from strong to severe thunderstorms, cold air funnels can develop under partly cloudy skies with only low to moderate instabilities.  A cold air funnel is a high based weak circulation that occurs in a cool or cooling air mass.  By high based, I mean they develop well above the earth's surface.  Since they are high base and weak, they rarely impact the ground.  Although they can look very threatening; even if they make contact with the land (which is extremely uncommon),  they will be very, very weak with max winds below storm force.

Unlike typical tornadoes, cold air funnels develop in a shallow cool air mass and often behind a cold frontal passage.  The mixing of cool air and windy conditions in the lower troposphere with air in the middle troposphere flowing in a different direction may spark the rotation that spins up the funnel.  If the air is moist enough and rises enough the condensation funnel will be visible.  These cold air funnels are fairly common near big water bodies (like Georgian Bay) since they are great moisture sources. 

What was spotted near Wasaga Beach and Minising today is a great example of a cold air funnel (not its more aggressive cousin Tornado associated with a thunderstorm).

If I didn't make it clear enough for you (I am not a writer), check out Wikipedia's explanation here.