PHOENIX — As former Hurricane Polo weakened over northwestern Mexico on Tuesday evening, the storm’s remnants battered the U.S. Southwest, flooding roadways and forcing residents in small New Mexico towns to evacuate over concerns about a dam failing.

Polo had struck the Mexican state of Baja California Sur in the morning with maximum sustained winds of 110 mph (177 kph). It crossed the Gulf of California and weakened to become a tropical storm as it moved inland to the northeast.

By Tuesday evening, the New Mexico Department of Transportation reported flooded roads and debris on highways across the state, while parts of Arizona had become especially drenched, leading to several water rescues.

That is after storms rolled through parts of the U.S. Southwest overnight Monday, saturating the ground, which can make flooding worse.

Later in the week, the flood risk is expected to move into parts of the central U.S., with heavy rain hitting Texas and Oklahoma beginning Tuesday night, according to the National Weather Service.

Southwest US sees heavy rains and floods

Bands of rain continued to sweep across the U.S. Southwest, causing desert rivers to surge and usually dry arroyos to rage with floodwater.

A resident enters his home surrounded by water brought by Hurricane Polo in Puerto San Carlos, Baja California Sur state, Mexico, Tuesday, Sept. 29, 2026. (AP Photo/Eduardo Verdugo)

Eduardo Verdugo/AP

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Eduardo Verdugo/AP

The potential failure of the dam in south central New Mexico prompted evacuations in three small communities with hundreds of residents along the Rio Grande. People in Rincon, Salem and Garfield were told to seek higher ground immediately “before conditions worsen.” Residents were later told to evacuate from nearby Hatch, home to prized green chile crops, and farther north in Placitas.

Wide swaths of the U.S. Southwest were under flood watches as the complex system of tropical weather spread northeast from Mexico, with Polo as the main event.

“Definitely looking at the chances for urban flooding,” weather service meteorologist Carter Greulich in Albuquerque said. “Don’t drive through flooded roadways. Remain out of the arroyos, especially in our urban areas.”

A person stranded on top of a vehicle in floodwaters west of Phoenix was rescued Tuesday morning. Video taken by Arizona Fire and Medical Services showed a helicopter lowering a rescuer to a person clinging to their overturned car. And in Zion National Park, in Utah, a helicopter rescued three people in Heaps Canyon after flash flooding hit.