Nighttime temperatures around here have been hovering around or below zero degrees Fahrenheit for the last few days. I'm afraid the usual pattern of winter temperature inversions in the Salt Lake Valley is settling in. I’m ready a January thaw. Now! Wouldn’t it be nice if we could get a Chinook’s here!
In case you are unfamiliar with what a “Chinook” is, here is a good definition from The Weather Notebook:
“The Chinook Wind is not called "snow eater" for nothing! This western wind can vaporize a few inches of snow in two hours, skipping the better known phase of melting known as slush. How does this happen?Chinooks happen frequently during the winters in Alberta, Montana, and other areas along the Eastern slope of the Rocky Mountains.
Chinook winds blow in from the Pacific in late winter and early spring. Their moisture evaporates as they pass over the Rocky Mountains. Once the winds come down from the mountains onto the high plains, the air can be quite mild and extremely dry,. When a Chinook takes effect local temperatures can warm up from as low as 5 degrees below zero to 60 or 70 degrees Fahrenheit. The air is so dry that when it hits snow, it sucks up the moisture, changing the snow directly into water vapor, bypassing the liquid slushy phase-- entirely. Called sublimation, this is a common way for snow to disappear quickly in arid climates.”
I haven’t had the privilege of witnessing one of these myself. Although I’d really like to – right about now would be nice, as a matter of fact!
I’ve heard wonderful legends of Chinooks as told from first-hand accounts by my Southern Alberta relatives. The best one I remember was a time when a Chinook came to the town of Cardston, Alberta area. The Chinook came to town, but only partway. Half the town was warm and thawed, while the other half was still frozen with snow and ice. There was about a 50 degree temperature difference between the two halves of town.
Now, wouldn’t a Chinook be nice right about now?