Tropical Storm Polo’s Remnants Threaten Southwestern U.S. After Mexico Landfalls

Tropical Storm Polo is poised to affect the southwestern United States after making two landfalls in Mexico, according to the National Hurricane Center. Although the system was downgraded from a hurricane to a tropical storm on Tuesday, it still poses a severe flood risk to a vast population stretch from Arizona to Iowa.

Polo initially struck Baja California Sur as a hurricane before traversing the Gulf of California and making a second landfall in Sonora. Moving northeast at approximately 21 miles per hour, the storm is forecast to cross northwestern Mexico Tuesday evening. Its remnants will continue tracking toward the U.S., expected to near El Paso by Wednesday morning with sustained winds around 35 mph, down from 65 mph earlier in the day.

Flash flood watches are currently active across a wide corridor extending from Phoenix to Des Moines. More than 14 million people face the danger of major flooding, with some locations potentially receiving up to two inches of rain per hour. The National Weather Service Prediction Center warned of a significant flash flood threat spanning the Four Corners Region eastward into the Central Plains.

Incidents of dangerous flooding have already occurred in southern New Mexico, where heavy rains have inundated roads and trapped motorists. CBS News meteorologist Rob Marciano highlighted concerns for Albuquerque, where rain may saturate the desert landscape with forecasts of about two inches of precipitation. Further south, rain in parts of Texas, including Dallas, may persist through Thursday, with some areas seeing totals exceeding seven inches.

Before weakening, Polo underwent extreme rapid intensification, surging from 45 mph to 150 mph between September 21 and 22. At its peak, the storm tied with 2009’s Hurricane Rick as the third-strongest on record for the Eastern Pacific, with maximum sustained winds of 180 mph. It also held the distinction of being the second-strongest hurricane ever recorded in the basin, trailing only 2015’s Hurricane Patricia.

Warmer ocean waters, moist air, and reduced wind shear have facilitated storm development in the Pacific, conditions bolstered by unusually strong El Niño patterns. Meanwhile, another major system, Hurricane Nolo, recently passed Hawaii’s Big Island, bringing heavy rain and wind to the state over the weekend.