Super El Niño Drives Record Rainfall
Over 20 trillion gallons of water have fallen in the Southwest, triggering evacuations and raising flood risks.
By Amit Chukwu ·
More than 20 trillion gallons of water have fallen across the Four Corners states and Nevada in the last two weeks, according to calculations by former National Oceanic and Atmospheric Administration chief scientist Ryan Maue.
The heavy precipitation is being driven by an extreme iteration of El Niño, a natural warming cycle in the Pacific Ocean. Meteorologist Jeff Masters of Yale Climate Connections described the current event as a super duper El Niño, noting that while strong iterations have occurred previously, this one is particularly intense.
The warming ocean waters are releasing additional moisture into the atmosphere while shifting global wind patterns. These changes redirect strong air currents toward the Southwest, creating ideal conditions for severe storms. Climate scientist Daniel Swain of the University of California Agriculture and Natural Resources stated that the likelihood of big precipitation in the Southwest interior is increasing, but the current degree of rainfall is unprecedented.
The impact has been immediate and severe. Flash floods on Sunday forced evacuations in northern New Mexico and central Arizona. In Colorado, a ski town prepared for its main river to rise to catastrophic levels. A separate wet storm system last week subjected southwestern states to days of continuous flooding.
Desert regions are especially vulnerable to these weather events because the ground absorbs water less effectively than other terrain. The combination of natural El Niño patterns and human-caused climate change is amplifying the effects. Meteorologist Randy Cerveny of Arizona State University explained that ocean temperatures are already warmer than they were a century ago, which makes these El Niño situations even more intense.
The phenomenon is also affecting weather patterns globally. Swain noted that Peru and Ecuador are experiencing record-breaking flooding, while parts of southeast Asia, including Indonesia, are drier than usual.
Experts expect the El Niño event to peak in December. At that point, it can more strongly influence jet streams, producing more extreme storms across the western United States. Park Williams of UC San Diego's Scripps Institution of Oceanography wrote in an email that the dice are certainly loaded for more heavy storms this winter and spring.
The event is not expected to end immediately after the peak. Cerveny said the heating in the Pacific Ocean has not yet reached its maximum, meaning similar events will continue. He noted that while El Niño can provide beneficial rainfall and fill reservoirs in arid areas, the associated storms and floods pose direct dangers to people and property.
