It's starting to feel like spring, but it's March; we all know there is much more winter to come - soon in fact! Early next week, midday feel-like temperatures will range from -15 to -20! Yup, take off your toques but whatever you do, don't tuck it away.
As we coast into the weekend, temperatures will fall below freezing behind the first of two cold fronts. Inevitably, there will be some ice.
We all have a few pet peeves and one of mine, oddly enough, is weather-related. It rears its ugly head a few times each winter: black ice. I don’t have a problem with the ice itself, but I do get a little wound up about how and when the term is used.
Yesterday morning, my radio alarm came on just as the traffic reporter was reading his road report. That’s when my heart skipped a few beats: my annual battle with the use of the term “black ice” was back!
Black ice is common in the dead of winter when the atmosphere has warmed up after a cold spell that left the ground and roadways well below the freezing point. Black ice is also known as "glare ice" or "clear ice" and typically refers to a thin coating of glazed ice on a surface – usually the road.
Black ice is not black at all; it is transparent, allowing the black asphalt to be seen through it. The thin layer of ice contains very little entrapped air in the form of bubbles; it's those air bubbles that give ice its usual whitish colour.
Water that freezes, or snow that melts and forms puddles that freeze, are good examples of ice - just not black ice.
Humans create most of the black ice on roadways. On a very cold morning, when the road is bare and the night was clear, you'll find icy spots at intersections as the rush hour gets going. Moisture from the exhaust of idling cars freezes on the cold roads and forms black ice.
Bridges can be dangerous too; the moisture rising off a body of water on a very cold day can leave a thin layer of black ice.
These days, the term "black ice" is used any time the temperature is below freezing and roads are slippery. But sometimes ice is just plain old ice.
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Cindy Day is the chief meteorologist for SaltWire Network
