A Summer Day in November

An atmospheric ridge over the Western U.S., combined with downsloping, southwesterly winds east of the Front Range, has brought summer-like conditions to Metro Denver in the middle of November; our afternoon high today was 74 degrees F.

Anyone who has not spent much time in this region likely imagines Denver to be a cold and snowy place; after all, it is the gateway to many ski areas.  But, while it may snow here from September through early June, we enjoy a relatively mild, sunny climate.  Warm weather interludes, like today's, occur throughout the colder months and are often followed by brief periods of rain or snow.

Indeed, the weather of the Front Range urban corridor is all about wind direction.  As storm systems approach from the west, we often receive downsloping, southwesterly winds ahead of the cold front; as the air is forced down from the Continental Divide to the Piedmont, it compresses, dries out and heats up, producing the summer-like conditions.  But once the storm moves east of the Divide and onto the High Plains, we usually receive upsloping, northeasterly winds; as the air is forced to rise by the regional topography, it cools down and it's moisture condenses as rain or snow.  In fact, rain and chilly air are forecast to arrive by tomorrow afternoon.