According to Newsweek, The National Weather Service (NWS) has issued flash flood warnings for regions within the Four Corners area as monsoonal thunderstorms intensify. The warnings apply to portions of southwestern Colorado, northwestern New Mexico, southeastern Utah, and northeastern Arizona, where heavy rainfall is anticipated through Friday. This increases the risk of localized flash flooding, particularly in areas with burn scars—lands previously scorched by wildfires.
Erinanne Saffell, a climatologist at Arizona State University, explained the monsoon pattern in the Southwest. “In the Four Corners region, we experience a summer monsoon structure, where winds from the South bring moisture that can form thunderstorms,” Saffell told Newsweek. As warm air rises, it carries moisture to form thunderstorm clouds, which can lead to flash flooding, lightning, strong winds, and microbursts.
The risk of flash flooding is especially high in the Four Corners due to the clayey nature of the soil, which is less absorbent and more likely to cause runoff. Saffell noted, “When precipitation hits these clay surfaces or areas affected by wildfires, it doesn’t infiltrate easily, increasing the likelihood of flash floods.”
https://x.com/NWS/status/1826433488738025538
In addition to flash flooding, monsoon thunderstorms can bring other hazards, such as dust devils—vortexes of dust-filled air—and gustnadoes, which combine characteristics of tornadoes and dust devils. Hail is also common, with some hailstones reaching up to 4.5 inches in diameter.
The NWS Forecast Office in Salt Lake City, Utah, advised residents to stay updated with the latest forecasts and be prepared to act in case of flooding. They emphasized the risks to slot canyons, dry washes, creeks, streams, recent burn scars, and other flood-prone areas. Saffell also cautioned drivers in the Southwest to be aware of flash flooding channels, especially those crossing highways, to ensure safety during flood events.
