Southwest Monsoon Heats Up This Week, Bringing Much-Needed Rain to the Region

As we normally see during the month of July, the Southwest American monsoon is showing signs of strengthening this week with dew points expected to climb across much of Southern Arizona, New Mexico, and a few places in Southern California. This comes at a time the region needs the rain now more than ever, after being heavily impacted by both exceptional heat and exceptional drought…

A “plume” of moisture lifting into Arizona from the South this week, as the Southwest American monsoon starts heating up.

Despite what many of us might think, a “monsoon” is NOT a torrential downpour. A monsoon is actually a seasonal reversal of low-level winds, which often times can lead to tropical downpours forming. Here’s how it works…

During the summer months across the desert Southwest, land temperatures get much hotter than the surrounding oceans. These hotter temperatures lead to rising air above the surface, causing a “heat low” to form. As the surrounding oceans stay cooler with relatively higher pressure, this difference in pressure is what causes our monsoon flow to form.

As air moves from high to low pressure, onshore Southerly winds bring tropical moisture into the region, leading to seasonal thunderstorms to form across much of Southeastern California, Southern Arizona, and New Mexico. Fun fact: This is the only region in the Continental US that experiences some form of seasonal monsoon!

This exact pattern is expected to develop over the region this week, with rainfall totals expected to reach up to 2 to 4″ across much of Arizona. Not expecting as much rain in New Mexico this week, with only 0.5 to 1″ expected.

The rainfall will be a very welcome sight for many across the region, which has been harshly affected by extreme drought. Right now, 57% of Arizona is experiencing exceptional drought — the most severe drought category. The drought is also severely affecting parts of California, Nevada, Utah, Colorado, and New Mexico.

It also comes at a time where this part of the country could really use a good cooldown from the rain. Excessive Heat Warnings remain in effect for all of Nevada, a large portion of California, and parts of Oregon, Idaho, Utah, and NW Arizona.

Unfortunately for these areas feeling the heat the most right now, the Northward & Westward extent of the coming monsoon this week will not be far enough North for places like Fresno, Bakersfield, Las Vegas, or Salt Lake City to see any of the cooling rain.

For more on your forecast for back home in Central Alabama, head over to:

https://www.cbs42.com/weather-birmingham-forecast/

That’s all for now…stay in touch with me on social media! You can always find the latest on our forecast in Central AL on Twitter by following me, @GriffinHardyWX. You can always reach out to me with forecast questions anytime by sending an e-mail to ghardy@cbs42.com.