The monsoon is near, which means that during summer, July thru September, the winds over Arizona and New Mexico, that normally tend to come from the west to northwest, shift direction and come from the south to southwest. This shift brings moisture-laden air from the Gulf of Mexico, Gulf of California and the Pacific Ocean. As the air moves inland the sun adds its heat and the mountains force the air to rise, thus creating thunderstorms.
These storms generally develop during the early to late afternoon and on into the evening, usually ending by late evening. Monsoon storms range from minor dust storms to violent thunderstorms with high wind gusts and heavy rains, which can cause extensive property damage and even loss of life1,2.
Fortunately most of these storm cells quickly pass over and don’t last long. The rains however can result in a heavy runoff that may last a day or so, after which some streams will continue with a lessening flow for several weeks.
A list of monsoon safety considerations plus a wealth of other tips and information can be found in the link reference 3. It is a recommended read particularly for those new to the area. It doesn’t take much rainfall to rapidly fill the washes, dry riverbeds and low places in the roads. Heed the warning signs “Do Not Cross When Flooded”. It never fails that a few folks don’t. They end up stalled in the middle of a flood waiting for help and most likely be awarded a “stupid ticket” complements from a policeman or worse yet, become a statistic. If out trekking, be especially aware of weather conditions and your location. While the storm cell may be some distance away, the drainage you are trekking in may be down stream from that area. So don’t park, camp or hike in areas subject to flooding. Avoid being caught and carried away by a raging water flow without the proverbial “paddle”.
The following video clips were taken during a storm in 2006. This should give you appreciation of a storm’s clout. We can use the rain so let’s hope a couple good storms come along this year.
Wind & Rain: This shows how sever the winds and heavy rains can be. [View]
Lightning & Thunder: Two scenes, the first in real time and the second in slow motion. Notice the lightning starts from the ground up and how close the strike was! [View]
Hassayampa River: Three scenes of the raging Hassayampa river the day after the storm. [View]
So what to do? Enjoy nature’s magnificent show during a monsoon storm – it can be an exciting relief break especially during the “dog days of summer”.