Chris_Dunn's Blog

     Around this time every year, you'll start to hear the term "monsoon" used a little more frequently.  Every year there always seems to be some confusion over what exactly that term means, such as when someone rushes into a building to get out of a heavy downpour and says. "Boy!  It's coming down like a monsoon out there!"

    Time now for us to clear things up with the real truth behind the monsoon.

What it is:  A seasonal reversal in wind direction.

What it isn't:  A heavy afternoon storm.

 
     The monsoon "season" in the Southwestern U.S. generally runs from early/mid July through early September, depending upon your exact location.     The National Weather Service office in Phoenix, Arizona has set parameters that define *when* the monsoon begins:  Three consecutive days with a dew point temperature of 55° or greater.  That rise in dew point temperature (moisture near the surface) means our seasonal shift in the wind is now bringing in moist air, moving up from the Pacific, Gulf of California and Gulf of Mexico.  That moisture causes thunderstorms to develop, which make a significant contribution to the annual rainfall for many locations across the Southwestern U.S.

    While Colorado is on the Northern fringe of the Mexican monsoon, we certainly do feel the impacts of this seasonal weather phenomenon.  The onset of the monsoon lessens fire danger, can result in flash flooding and produces beneficial rain at the hottest time of the year.