Southwestern US faces severe flooding risk from tropical moisture

The Southwestern United States is facing a rare, high-magnitude storm system driven by unusual tropical moisture from the Pacific and the Gulf of California. The Four Corners region, including Arizona, Utah, Colorado, and New Mexico, is under intense scrutiny as authorities monitor river levels for potential massive flooding.

In Arizona, cities such as Phoenix and Tucson are on alert for flash floods. In the mountainous areas of Colorado and Utah, there is a significant risk of landslides and mudflows that could damage electrical infrastructure and isolate communities. In New Mexico, dry riverbeds may experience sudden rises in water levels. The Colorado River basin is a primary area of concern, with the potential for exceptional flows to test the limits of dams and levees.

Complementing these regional concerns, the National Water Center has issued a national Flood Hazard Outlook valid through September 27. This monitoring tool, utilized by the National Weather Service, provides a high-level overview of potential flash, urban, and river flooding across the country to assist emergency responders and local authorities in preparation.