Presentation on theme: "Colorado Climate: How would you describe it?"— Presentation transcript:
1 Colorado Climate: How would you describe it? Overall -- semi-arid with precip gradually increasing as you go eastward into Kansas and Nebraska -- dry winters, wetter springs and summer, highly changeable weather, often windy, and some occasional monstrous thunderstorms with damaging hail.--provided by Nolan Doesken, Colorado Climate Center
2 Agenda A. Topography B. Local Influences on Weather C. Upslope and Downslope
3 A. TopographyColorado lies astride the highest mountains of the Continental DivideMountain ranges extend North and South through the middle of the stateThe average elevation is 6800 feet, the highest State in the UnionEastern plains
4 B. Local Influences on Weather North Facing Slopes vs South Facing1. North Facing SlopesWetter so they support cool, wet spruce forestsSupport Glaciers2. South Facing SlopesArid; host aspen and poplar treesThe difference between sun and shade may be as great as degrees C or degrees F.
6 More Local Influences on Weather 3. The Continental DivideOur weather must climb and crest the divide.Eastern slopes are characterized by much drier climates than areas only a few kilometers on the Western side of the divide.
8 Local Influences… 4. Latitude Latitude affects the angle with which the sun’s rays hit the Earth. The farther from the equator, the sun’s rays impact the Earth at increasingly shallow angles.With the northern latitude of the Rockies in excess of 50 degrees North our sunlight never comes from directly overhead.
9 Even more Local Influences.. 5. AltitudeAs you climb in elevation, the air pressure decreases. Thinner atmospheres are less capable of holding heat, resulting in a gradual drop in temperature.For every 300 meters climbed the average drop in temperature will be degrees C.Wind increases with altitudeAs an average, a climb of 30 meters (100 feet) delays spring by one day!
10 C. Upslope vs DownslopeUpslope Flow – Air that flows toward higher terrain, and is forced to rise. In Denver, wind from the East.Bring an increase in clouds and often rain or snow to DenverDry weather will hold west of the Continental DivideDownslope (Chinook) – winds from the West; typically warm and dry.