Polo’s Remnants Drench Flood-Weary US Southwest
The remnants of Hurricane Polo swept into the U.S. Southwest on Tuesday, dumping heavy rain on a region already saturated by earlier storms, triggering flash flood emergencies in southern New Mexico and forcing residents of several small communities to evacuate over fears a dam could fail. According to NPR, the system pushed desert rivers to surge and usually dry arroyos to rage with floodwater as the flood threat began spreading toward the central United States.
Polo made landfall Monday night in Mexico’s Baja California Sur with maximum sustained winds of 110 mph (177 kph). It crossed the Gulf of California and weakened as it moved inland to the northeast, but its moisture-laden remnants carried enormous rainfall potential into the desert Southwest.
A Dam on the Brink
The most urgent concern centered on McLeod Dam, an earthen structure northwest of Hatch in New Mexico’s Doña Ana County. Operators reported the dam was on the brink of imminent failure, prompting the National Weather Service to issue a Flash Flood Emergency warning of “catastrophic damage and life-threatening situations” for anyone downstream.
Doña Ana County issued evacuation orders for the communities of Rincon, Salem, Garfield, Hatch and Placitas, each home to fewer than 2,000 residents, with Interstate 25 designated as the primary evacuation route. As KVIA reported, officials urged residents to move to higher ground immediately and directed evacuees to shelters at the Radium Springs and Doña Ana community resource centers, where the American Red Cross provided services.
By roughly 10:46 p.m. Tuesday, the county lifted evacuation orders for Salem, Hatch, Garfield and Placitas, though the order remained in effect for Rincon, where a stream breached levees near a water treatment plant. The Albuquerque Journal reported that crews were working to ease pressure on the dam, and that a Garfield resident described preparing sandbags and weighing whether to flee as the water rose.
Schools in the Hatch Valley announced they would close Wednesday.
Rescues Across the Region
The flooding stretched well beyond New Mexico. In Arizona, a person stranded atop a vehicle in floodwaters west of Phoenix was rescued Tuesday morning by helicopter, and north of Phoenix a truck was swept away in a wash before its driver escaped safely. In Utah, a helicopter rescued three people in Heaps Canyon in Zion National Park after flash flooding, while the East Fork of the Virgin River surged with floodwater and swept a shipping container downstream.
In Orderville, Utah, resident Sabrina Dubay found her home surrounded by the river. “The river came in and swept around the entirety of our house,” she told the Associated Press. “It was coming in through our front doors.”
The Weather Channel reported that some areas had picked up more than 4 inches of rain in 36 hours, and that dozens of water rescues were underway as drivers became caught in fast-moving floods. Forecasters warned that flash flooding and mud flows remained a danger in wildfire burn scars, including areas of southern Colorado affected by the Aspen Acres Fire.
A Soggy Stage and an El Niño Backdrop
The flooding was worsened by antecedent conditions: an unusually wet September had already saturated the ground across the region, leaving rainfall nowhere to go but into runoff. “Runoff is likely going to start much quicker and lead to those flooding impacts quicker,” National Weather Service meteorologist Carter Greulich in Albuquerque said, warning residents not to drive through flooded roadways or linger in arroyos.
The rocky, sparsely vegetated desert Southwest typically receives less than 10 inches (25 centimeters) of rain a year, making flash flooding a perpetual risk. The region’s mountainous terrain can further intensify rainfall through orographic lift.
The broader pattern fits a year of heightened Pacific storm activity consistent with El Niño. As NPR reported in June, forecasters warned that a newly arrived El Niño could bring strong global impacts, and NOAA later projected a 63% chance of a very strong El Niño. Even as parts of New Mexico, Colorado, Oklahoma and Texas remain in drought, forecasters cautioned that rain falling too quickly produces dangerous flooding rather than relief.
What’s Next
The flood risk was forecast to spread eastward and northward into the central U.S. through the week, with heavy rain expected from Texas to Minnesota. The National Weather Service’s Weather Prediction Center called for three consecutive days of “moderate risk” for excessive rainfall from Tuesday through Thursday, and nearly 80 trillion gallons of water could fall across the country this week.
The threat is expected to continue into the weekend as Polo’s remnants interact with a slow-moving frontal boundary across the Plains. Even as some New Mexico residents returned home, officials cautioned that downed power lines, damaged roads and lingering floodwater meant the danger had not fully passed.