5 Basic Facts About Chinooks from Andrew Schultz

Breakfast Television’s meteorologist shares some interesting facts about Mother Nature’s gift to Calgary.

How a chinook forms

A chinook occurs when a warm, moist air mass moves east from the Pacific and rises over the Rocky Mountains, where it cools, loses moisture and condenses into cloud cover. As it moves down the mountain, the air mass warms drastically and the energy expelled from the process funnels down and creates a dramatic change in temperature.

How the chinook arch forms

When the air mass slides down the east side of the Rockies, the clouds are forced apart into a uniform line that matches the mountain range. This uniform line is the chinook arch. “It’s almost like a knife coming through and cutting the clouds,” says Schultz, “like the air mass is using the mountain range as a ruler.”

Where chinooks occur

Chinooks don’t only occur in Calgary. “You need a few elements, and the big one is topography,” says Schultz. Areas where there are major mountain ranges in close proximity to the western coastline, including Argentina and the Swiss Alps, also experience chinook-like winds.

When chinooks happen

Calgarians can feel chinooks as summer transitions to fall, although they are more common, and noticeable, in the depth of winter and during the transition to spring.

What kind of temperature increase can be expected

It is not unusual for the temperature to increase as much as 20C.