Torrential rainfall from the remnants of Hurricane Polo and Tropical Storm Rachel threatened more than 28 million people across the Southwest and Central Plains with life-threatening flash floods, following Polo’s landfall in Mexico. Flood watches were issued across nine states as deep tropical moisture surged northward. This moisture merged with a separate upper-level low-pressure system coming from the West, according to the National Weather Service and the FOX Forecast Center.
Meteorologists warned that up to 30 states could face impacts throughout the week. Precipitation totals were expected to reach 6 to 8 inches or more in heavily affected areas. A deep plume of moisture moved northward through northern Mexico, Arizona, and New Mexico, producing rainfall rates of up to two inches per hour. Residents in dry washes, slot canyons, burn scars, and low-lying areas were strongly advised to avoid travel.
Storm Track and Mexico Landfalls
Hurricane Polo initially made landfall as a Category 2 storm on Baja California Sur, Mexico, bringing damaging wind gusts and life-threatening flash floods. Before impacting the peninsula, the storm achieved remarkable intensity, reaching Category 5 strength in the Eastern Pacific with the second-lowest pressure ever observed in the region.
After tracking over the Gulf of California, the system made a subsequent landfall in mainland Mexico. It dropped up to 10 inches of rain and triggered widespread mudslides in steep terrain. In response to the intensifying multi-day threat, California Governor Gavin Newsom declared a state of emergency to provide communities and first responders with necessary resources.
Impacts Across the U.S. Southwest and Plains
The slow-moving tropical moisture plume pushed deep into the U.S. interior, triggering rare and historic weather events. Jonathan Finch, a meteorologist at the National Weather Service office in Dodge City, Kansas, noted that heavy rains from tropical remnants are exceptionally rare across western Kansas.
- Southwest: Up to an additional 3 to 5 inches of rain fell, with hourly rates reaching 1 to 3 inches. Nearly the entire state of Arizona, including Flagstaff and Tucson, was placed under a Flood Watch.
- Southern Plains: Parts of Texas and Oklahoma, including Dallas, Austin, and San Antonio, braced for 3 to 5 inches of rain. This marked the heaviest rain event in eastern Oklahoma since June and in the Dallas-Fort Worth Metroplex since early July.
- Central Plains and Midwest: A distinct stripe of 3 inches or more of rain was tracked from parts of Kansas into southern Nebraska, northern Missouri, southern Iowa, and northern Illinois.
Concurrent Threats and Safety Guidelines
Adding to the active tropical activity, Tropical Storm Rachel formed off Mexico’s southwestern coast, generating large swells, life-threatening surf, and hazardous rip currents along coastal areas. Meanwhile, authorities urged the public to heed warnings regarding inland flooding.
Emergency officials reiterated standard flood safety protocols, reminding motorists: “Turn around. Don’t drown.” Driving into flooded roadways can quickly stall or submerge vehicles in minutes or even seconds. Residents in flood-prone zones were encouraged to monitor local alerts closely and relocate to higher ground when flash flood warnings or emergencies are issued.
