A natural warming cycle, known as El Niño, is significantly intensifying heavy rains and flooding in the Southwestern United States, according to experts. This El Niño iteration is described as particularly extreme, with some scientists calling it a "super duper El Niño."
El Niño events, which occur irregularly every couple of years, involve the warming of Pacific Ocean waters, leading to increased moisture in the atmosphere that can fuel storms. While not the sole cause of the severe weather, scientists state that El Niño is making heavy rainfall more probable and more intense across the southern U.S.
Recent weeks have seen substantial rainfall in the Four Corners states and Nevada, with over 20 trillion gallons of water falling on the region, according to calculations by former National Oceanic and Atmospheric Administration chief scientist Ryan Maue. Flash floods in late summer prompted evacuations in northern New Mexico and central Arizona, while a Colorado ski town prepared for its main river to reach potentially catastrophic levels. This follows another series of storms the previous week that caused widespread flooding across the Southwest.
Experts attribute the heightened intensity to warmer ocean temperatures and shifting atmospheric winds. Climate scientist Daniel Swain of the University of California Agriculture and Natural Resources noted that while increased precipitation is typical for the Southwest at this time of year, the current event is occurring to an unprecedented degree.
Human-caused climate change has already led to warmer global oceans, and El Niño further exacerbates these conditions. Meteorologist Randy Cerveny of Arizona State University explained that warmer baseline ocean temperatures make El Niño events more intense than they would have been historically. "The fact that the ocean temperatures are already warmer than they were, say, 100 years ago, makes these El Niño situations even more intense," Cerveny said.
The phenomenon is also altering weather patterns globally, with regions like Peru and Ecuador experiencing record-breaking floods. The El Niño event is expected to peak in December, with its effects potentially continuing for months afterward. Experts advise staying informed about weather forecasts, planning accordingly, and adhering to evacuation warnings from local authorities.