As I write this post, three domes of high pressure dominate the weather map across North America. One dome is centered over the northern Great Basin, the second is over the Gulf of Mexico and the third is over Eastern Canada.
In the central region of high pressure domes, air is sinking and cloud formation is suppressed; along their outer rim, however, air is circulating in a clockwise direction. Where they interact, cold or warm fronts arc across the landscape and centers of low pressure produce uplift; if sufficient moisture is present, rain or snow develops.
Currently, strong southwesterly winds are raking the Front Range urban corridor, just ahead of the cold front associated with the Great Basin dome; we are in the mid 70s F while Cheyenne, Wyoming, 90 miles to our north, is in the mid 50s F. Across the Great Plains and Southeast, the Gulf of Mexico dome is in control and afternoon temperatures are in the 80s and 90s F. Finally the cool Eastern Canada dome reaches down to the Mid Atlantic region and out across the Great Lakes. Rain is falling across the Northern Plains and Mid Atlantic States, where these atmospheric domes abut one another. Unfortunately, we do not expect any significant moisture from the cold front as it drops along the Front Range.
