Welcome To Monsoon Season - Here's What to Expect

WELCOME TO THE NORTH AMERICAN MONSOON SEASON.

The North American Monsoon Season (NAMS) spans from June 15 through September 30th. It is also referred to as the Southwest Monsoon and is typically strongest during July and August.

What is the North American Monsoon?

The North American Monsoon is a seasonal change in atmospheric circulation that occurs during the summer across northwestern Mexico and the southwestern United States, including parts of Arizona, New Mexico, Nevada, Utah, Colorado, and California. The monsoon can bring stormy weather, flooding rains, dust storms, extreme heat, and wildfire concerns to the region.

As the land heats up during the summer months and high pressure develops over the Southwest, a shift in wind patterns pulls moisture northward from the eastern Pacific Ocean and the Gulf of California. This increase in moisture provides fuel for thunderstorms. As a result, the region can experience afternoon and evening thunderstorms, heavy rainfall over short periods of time, frequent lightning, gusty outflow winds, flash flooding (especially in canyons and burn scar areas), and occasionally dust storms.

Seasonal Outlook

For the upcoming season, the Climate Prediction Center's Seasonal Drought Outlook indicates that drought is likely to persist across portions of the Four Corners region, but improvement is expected in many areas. Meanwhile, drought conditions across Nevada are forecast to persist and may even expand.

Something to note, the CPC is not guaranteeing a wet monsoon season, but they are favoring above-normal precipitation and improved odds of drought relief.

Why is it so important?

The monsoon provides a large portion of the annual rainfall for many desert locations across the Southwest. In Arizona, for example, the monsoon can account for nearly half of the state's yearly precipitation. This rainfall can help reduce drought impacts, improve soil moisture, and lower wildfire risk. However, it can also bring hazards such as flash flooding and dangerous lightning.