Rocky Mountain Climate - A General Overview

Weather is controlled by the flow of air, water vapour and airborne particulates. In high school, most of us learn the water cycle, with water evaporating from lakes returning to the earth as rainfall. We also learn about the diffusion of materials from areas of high concentration to areas of lower concentration. Both of these processes play a critical role in the weather around us. The actual interaction of many factors will create the final package which we see as weather.

Since warm air is lighter than cold air, it will rise. Around this column of warm air, called a convective cell, there will be a corresponding area of sinking air which rushes in to fill the vacuum created by the rising warm air. This rising and dropping of air is one of many causes of air movement which we know as wind. These convective cells can occur on a very small scale, or conversely on a much larger global scale.

As air masses of varying compositions encounter one another, they will react based on the temperature of the air mass and the corresponding air pressures. The boundary between two differing air masses is called a front. Since cold air is heavy, Cold fronts will displace warm air masses abruptly upward, showing a band of rising cumulus clouds near the boundary of the two fronts. These clouds are formed when the rapidly rising warm air reaches the condensation level, the point at which the water vapour within the clouds releases heat and forms water droplets. This release of heat increases the buoyancy of the weather system and adds to the vertical buildup of the clouds.

In the opposite situation, where a warm front moves in on a cold air mass. The warm front will climb gradually over the colder air, usually forming bands of stratus clouds at progressively higher elevation.

 

 

Climate Data

  Elev
(m)
Mean
Temp
(C)
Jan
High
(C)
Jan
Low
(C)
July
High
(C)
July
Low
(C)
All Time
High
(C)
All Time
Low
(C)
Precip
(mm)
Snow
Fall
(cm)
Calgary 1077 3.9 -3.6 -15.7 23.2 9.5 36.1 -45.0 300.3 135.4
Banff 1397 2.9 -5.3 -14.9 22.1 7.4 34.4 -51.2 281.2 243.8
Jasper 1061 3.1 -6.0 -15.6 22.2 8.0 36.7 -46.7 281.6 143.9
Edmonton 715 2.1 -8.7 -19.8 22.5 9.4 35.0 -48.3 357.8 127.1
Golden 785 4.6 -6.0 -14.4 24.9 9.4 40.0 -46.1 303.6 184.0
Revelstoke 443 6.7 -2.6 -8.7 25.3 11.1 36.7 -29.4 612.2 445.3

All Material Ward Cameron 2005