Seeing saucers in the sky
You don’t have to believe in UFOS to see a cloud that looks like one — just ask Charlene Lawrence. She was out one week ago yesterday and couldn’t help but notice this very unusual looking cloud over Dingwall, Cape Breton. It was a showstopper, to say the least. Marie Fitzgerald spotted the same cloud from Cape North.
Clouds appear, grow, move through, and dissipate all the time; many go unnoticed. But not one that looks like this. There is nothing common about this cloud that is commonly referred to as the UFO cloud. In fact, authorities receive a few calls each year about the invasion of UFOS when these beauties dot the sky.
First, let’s start with its proper name: Altocumulus lenticularis, or lenticular cloud.
The cloud is a stationary, almond-shaped cloud that forms over higher elevations; you’ll
almost always find it in perpendicular alignment to the wind direction. It develops where stable, moist air flows over a mountain or a range of mountains. In some cases, it doesn’t take a very significant elevation to trigger the process.
The cloud itself forms on the downwind side of the lift. If the temperature at the crest of the wave drops to the dew point, moisture in the air can condense to form a lenticular cloud. As the moist air moves back down into the bottom of the wave, the cloud often starts to evaporate.
To confuse matters, you don’t always need an orographic lift for a lenticular cloud to form. These
have also popped up in nonmountainous places as a result of wind shear created by a front. Wind shear is the difference in the wind’s speed or direction over a relatively short distance in the atmosphere.
Pilots of motorized aircraft avoid flying near lenticular clouds because of the turbulence that accompanies them. Glider pilots go looking for them; wave lift is usually smooth and strong, and allows gliders to soar to great distances.
I hope this solves Cape Breton’s curious cloud caper.