Back-to-back extreme rain events in late October and early November 2026 inundated the Four Corners region of the U.S. Southwest, causing river levels to spike to record or near-record highs and triggering damaging floods. While the storms provided much-needed relief for short-term drought conditions, the sudden surge in water levels resulted in significant hazards for communities along major river systems.
Satellite imagery from the Operational Land Imager on Landsat 9 captured the dramatic change in Navajo Reservoir, located in northern New Mexico and southern Colorado. Data from the U.S. Army Corps of Engineers indicates that the reservoir’s water level rose by nearly 60 feet (18 meters) between September 20 and November 7, 2026. By November 7, the reservoir had reached its highest level since August 2019, standing at 108 percent of its average capacity for that date. This marked a sharp increase from September 20, when the lake held just 60 percent of its average capacity, a figure influenced by a snow drought across the West during the 2025-26 winter that limited spring snowmelt growth.
The heavy rainfall caused the San Juan, Piedra, and other rivers to swell with runoff, with Pagosa Springs, Colorado, being particularly hard-hit. Located about 40 miles (64 kilometers) northeast of the reservoir along the San Juan River, the town received 5.05 inches (12.8 centimeters) of rain during the first storm event, pushing the river to major flood stage on October 23. A second round of rain on November 1 caused the river to spike again, nearly reaching the record level set during a devastating flood in 1911. In response, officials issued evacuation orders, and emergency responders rescued dozens of people as water inundated streets and damaged property.
Widespread heavy rain and flooding affected southwest Colorado, southeast Utah, northern Arizona, and northwest New Mexico over recent weeks. Precipitation totals from early September through early November were two to four times the average throughout the Four Corners region, an area previously beset by long-term drought exacerbated by high temperatures and snow drought in 2026. According to the U.S. Drought Monitor’s November 3 summary, the fall storms have ended short-term drought conditions for the Southwest and Great Basin, although long-term drought persists in some areas.
“Short-term drought has ended for the Southwest and Great Basin,” noted the U.S. Drought Monitor in its November 3 summary.
Experts attribute the wet weather to an ongoing El Niño event, which strengthens the segment of the jet stream flowing eastward near the equatorial Pacific. The low-pressure system delivering the heavy rainfall in autumn 2026 was at a low latitude for the time of year and drew energy from unusually high ocean temperatures. Such El Niño patterns increase the likelihood of moisture-laden storms being steered across the Southwest interior, contributing to the extreme precipitation observed in the region.
<small>Source: NASA — read the original story there.</small>
