By Carlton Moeller
According to a Colorado College brochure I read while visiting this school as a prospective student, Colorado Springs gets the most precipitation of all cities in Colorado. We have all heard the classic Colorado sales pitch: getting 300 days of sunshine a year makes it one of the sunniest places to live in the country. However, this advertisement is more of a myth, as there is no real way to classify a “sunny day” in Colorado when the first half of the day can be white-out blizzard while the afternoon can warm up to 70 degrees to melt the recently fallen snow in a mere six hours. While this example may be a great exaggeration, a sliver of truth resides regardless.
If one pays much attention to what the weather forecasters on TV say about the Colorado Springs region, the name Palmer Divide comes up quite frequently. It is an area of higher elevation which lies between Colorado Springs and Denver and acts as a sort of dam separating the weather of these two locations.
To understand the effect this region has on our weather, let’s first examine what changes in altitude do to air. When moist air reaches an area of higher elevation, such as a mountain or the Palmer Divide, it is cooled and condensed while being pushed upward. This effect ultimately condenses the water in the air into congregations of water droplets which form clouds. When these clouds become dense enough, they precipitate, creating rain. Rain removes moisture from the air and places it on the ground. So now as the dry air continues over the peak of the mountain, it begins a descent while expanding and warming greatly. This falling of dry air over mountains is called a Chinook Wind and it can have very drastic effects. For example, in 1972 in Loma, Mont., a Chinook Wind caused a temperature change of 103 degrees, going from -54 degrees to positive 49 degrees in a matter of 24 hours.
The Blackfoot People of Alberta and Montana called these winds “Snow Eaters” because the combination of their dryness and warmth is a dastardly condition for snow just trying to chill. Colorado Springs is surrounded by two areas of high elevation, the Palmer Divide and Pike’s Peak; depending on the direction from which the moist air is flowing, there can be drastically opposing effects.
Colorado storms often come from the West, which means Colorado Springs receives many more Chinook Winds from Pikes Peak than precipitation events. However, when it comes to the North to South axis, Colorado more often gets moist air from the south. The Palmer Divide is just north of us, meaning that a North-South wind will often leave us wet and cold as opposed to the East-West dry Chinook Winds.
All these factors combine to create a microclimate with extremely high variability, where in the morning there may be a northern wind which brings a blizzard but by the afternoon an eastern Chinook Wind will melt it all and by the end of the day it will be as if nothing ever happened. So, the next time you think a storm might be rolling in, before immediately relying on your phone, test your boy scout skills, lick your finger, feel the wind, and try to predict the weather.