The Southwest U.S. is bracing for heavy rainfall and flash flooding as Tropical Storm Priscilla and another storm system move in over the weekend.

The National Weather Service has issued flood watches across Arizona, Southern California, Nevada, Utah, and Colorado, with a Level 3 (out of 4) flood risk for parts of Arizona, including Phoenix and Flagstaff.

Forecasters warn that deep tropical moisture could bring 2 to 6 inches of rain, especially in vulnerable areas like burn scars and slot canyons.

A second storm, Tropical Storm Raymond, is also expected to bring additional moisture to southeastern Arizona, Axios has reported.

Experts note that climate change is intensifying these extreme precipitation events, increasing the risk of flooding across the region.