Monsoon Moisture Next Week
For those who have lived in the desert Southwest, you know that there is a wet season there. And it’s not in the winter. Here’s the average monthly rainfall for Tucson AZ. The months of July, August and even early September are the wettest months. Meanwhile, in the Inland Northwest, these are the driest months. The cause of the summer rains in the Southwest is known as the Southwest Monsoon. A monsoon is defined as a seasonal shift in winds that cause a distinct change in the precipitation pattern. In the Southwest, this change in wind direction is the result of persistent high pressure during the summer near the Four Corners area. Air rotates around a high pressure center in a clockwise direction. This acts to draw moisture up from Mexico into Arizona and New Mexico. Typically this moisture then rotates across southern Utah and into Colorado. This is the “Frequent” pattern in the image below (courtesy of https://opensnow.com/ ) Occasional...