Topographic Features Impact On The Weather
The first topographic feature that I would like to talk about today is the Rocky Mountains. The Rocky mountains with their rugged terrain and high elevation can really become a large impact on weather patterns in the United States.
First, the Rockies provide the Central Plains with the cold air aloft that is needed in the formation of severe weather to include tornadoes.
Secondly, the Rocky mountains act as a barrier for any large weather system that moves onshore along the Pacific Ocean. What usually happens is the system runs into the western slopes of the mountains and dumps a vast amount of precipitation leaving the system to weaken. However around Southern Colorado you will see that pressure systems regain their strength when they make it around the corner of the Rockies.
Third, the Rockies are responsible for is what is known as Chinook Winds, more commonly referred to as the “Snow Eaters”. This means that the winds warm very fast as they flow down the side of the mountains and this extensive warm-up of the temps creates a vast increase in snow melt on the sides of the mountains and down in the valleys.
The fourth feature that the Rockies impact the weather is what is known as Cold Air trapping. When a strong high pressure system from Canada moves southward towards the plains, it will trap the cold air on the front range from Nebraska and South Dakota keeping it colder in the region. This is because cold air is dense and does not rise up in the atmosphere allowing the mountains to act as a trap.