People who live up against the southern Rockies have experience Foehn wind, but what is it exactly, and how is it created?
According to Environment & Climate Change Canada Meteorologist Stephen Berg, Foehn wind is a dry, warm downslope wind on the leeward side, or Eastern side, of the Rockies that can raise the temperature of the area.
"In the case of Alberta, you get circulation coming on towards British Columbia, coastal B.C., and it reaches eastward," explains Berg. "And a lot of the moisture ends up condensing and falling out over the Rockies and coastal mountains. Once it gets to Alberta, most of the moisture is kind of lost from this up and down movement through the mountains and valleys in B.C."
Once it hits the eastern edge of the Rockies, the air moves downwards, where it dries and warms up even more, resulting in very low relative humidity levels on the east side of the Rockies as a result.
"What happens with that is the cooling process that occurs over the Rockies when the humid air moves upward, the cooling is not as rapid with the humid air as it is with the warming on the east side of the Rockies with the dry air. So, you end up having an air mass that's 15 degrees as it approaches the B.C. coast, becoming maybe 25 degrees at the base of the foothills as it approaches Calgary or Okotoks."
In Canada and the United States, these winds are known as Chinook winds.
The name Foehn has Latin origins, but is a German word for the moist winds blowing off the Mediterranean Sea and over the Alps, but the term Chinook in North America originated from the Chinook people who lived near the ocean along the Columbia River.
On top of people complaining of headaches and migraines when there is a Chinook occurring, Berg says that while chinooks can cause snow to quickly melt in the wintertime and high winds, it doesn't pose much of a problem to the environment.
In fact, these winds can make a foot of snow vanish completely in a single day.
Berg adds that Chinooks could happen in the summer months, but they primarily occur in the wintertime.
These winds can cause circulatory problems and headaches, but researchers have found that the warm temperature these winds bring are beneficial to humans in most cases.