A broad atmospheric trough currently extends across most of the Lower 48 States, allowing dry, cool air to plunge southward from Canada. Dew points are below zero degrees (F) in some parts of the West.
Here along the Colorado Front Range, the air is crystal clear; bright sunshine has pushed the afternoon high into the mid 40s F, with a dew point of 1 degree F. In other words, the air is so dry that its temperature would have to fall to 1 degree F before fog or precipitation could develop.
Of course, this brilliant dryness, while producing spectacular vistas, is not currently welcome across the West, where a severe drought persists, augmenting the risk of wildfire. High pressure within the trough is shunting Pacific moisture toward Alaska and the Pacific Northwest and, until this "blocking high" breaks down, hope for snow is but a dream.
