Some people ask me what it is I do all day. One of these days, I’ll timeline my day for you. In the meantime, suffice it to say, there’s very little downtime.
While I was putting the finishing touches on today’s column, I saw a message come in on my Facebook page. Rhonda Weatherbee posted a photo with the comment, “This is a cool cloud.”
I’ll say it is! If you recall, Thursday afternoon’s weather was quite changeable – from sun to cloud with showers and snow pellets. A cold front had moved across the region Wednesday night, leaving a cool and unsettled air mass in its wake.
If you look closely at the photo Rhonda took last Thursday afternoon, you’ll see a white, tube-shaped cloud that looks a lot like a funnel. Well, it is indeed a funnel, but not your typical summer funnel. Unlike the related phenomenon associated with severe thunderstorms, cold-air funnels are generally associated with partly cloudy skies in the wake of cold fronts. The funnels are most common in the fall and spring, when the sun heats the lower levels of the atmosphere, causing convection to bubble up and form showers, but temperatures higher-up above the ground are quite cold. The mixing of cooler air closer to the ground with air flowing in a different direction above it causes the rotation on a horizontal axis. When atmospheric conditions are just right, that rotating parcel of air can be deflected vertically to become a funnel cloud, but a cold-core funnel cloud.
A typical tornado forms in a warm air mass that is part of an energetic synoptic environment, while a cold-core funnel forms in a cool air mass that is part of a quiet, benign synoptic environment. The cold air or cold-core funnel is usually very weak and brief and rarely causes damage. Unlike its warm-weather cousin, it is not associated with supercells or major thunderstorms. Cold air funnels are usually harmless.
I’m glad I noticed Rhonda’s message and stopped what I was writing to address it. The column that I was working on will appear in Tuesday’s publications. It, too, deals with some “very cool” clouds spotted over our region. Thank you for looking up and being curious!
Have a wonderful, safe weekend.
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Cindy Day is the chief meteorologist for SaltWire Network
