Potential Flooding Threatens Southwest from Hurricane Remnants

PHOENIX, Arizona – A former hurricane, now weakened, is expected to bring significant rainfall to the Southwest United States this week, increasing the risk of flash flooding in arid regions. As moisture from Tropical Storm Priscilla moves northward, meteorologists predict that areas in Arizona, New Mexico, and beyond could see more than a month’s worth of rain in just a few days.

According to the National Weather Service, the storm’s effects will start to be felt by Thursday, with the most intense rainfall expected between Friday and Saturday. A Level 3 flood threat is in place for central and northeastern Arizona, including Flagstaff, indicating a high possibility of widespread flash floods.

This rainfall could resemble conditions from previous years when severe flooding impacted the same areas. For example, in 2018, remnants of Hurricane Rosa led to more than 2 inches of rain causing significant disruption in Phoenix, the city’s wettest October day on record.

Weather Prediction Center forecasters indicate that rainfall totals could range from 2 to 4 inches, with isolated areas potentially receiving up to 6 inches. The heavy moisture levels are being enhanced by a dip in the jet stream over the West Coast, which will pull Priscilla’s moisture northward.

While the storms will primarily affect southern Nevada, Arizona, and parts of southwestern Colorado, areas like Flagstaff may see totals exceeding their monthly average of around 1.50 inches within just 48 hours. This intense rainfall can quickly lead to flooding in the desert landscape, particularly in dry washes and arroyos that easily fill with water.

Officials warn that it only takes a small amount of rain over a short period to create dangerous flash flood conditions in these typically dry areas. The most vulnerable regions include small streams and side canyons, especially those affected by recent wildfires.

This weather pattern could set the stage for another round of storms early next week, as another tropical system is likely to form and move northward. The extended period of high moisture content in the atmosphere could facilitate prolonged rainfall and increase the risk of flooding throughout the Southwest.