Ever since I first heard about “atmospheric rivers” from Cliff Dahm, the biologist who until recently headed science efforts for the Delta Stewardship Council, I’ve been asking every scientist who I heard talk about them whether they can make it all the way to New Mexico. AR’s are these amazing storms that blast California like a firehose, and they’re getting increasing attention in the climate-policy interface in California because of the importance of their presence, or absence, in determining whether that state has good or bad water supply years.
But they’ve been primarily a California thing. Can they push their moisture past the mountains and make it all the way to New Mexico?
Mike Dettinger, California’s “Dr. AR”, sent around a paper today (pdf) that pushes the boundary in our direction. It was a memorably impressive January 2010 storm, which came close to setting records (and in some cases set records) for runoff in the high country along the Mogollon Rim in Arizona and in the Gila Mountains of southwest New Mexico:
The AR was oriented nearly orthogonal to the Mogollon Rim, a major escarpment crossing much of central Arizona, and was positioned between the high mountain ranges of northern Mexico. High melting levels during the heaviest precipitation contributed to region-wide ?ooding, while the high altitude snowpack increased substantially. The characteristics of the AR that impacted Arizona in January 2010, and the resulting heavy orographic precipitation, are comparable to those of landfalling ARs and their impacts along the west coasts of midlatitude continents.
See also this shot from Wikipedia:
January 2010 was part of the last moderate El Nino episode before La Nina took over and drought conditions resumed. That AR phenomena resulted in moderate flooding even in the NM Gila region as rainfall and melting snow combined to the flood out the approaches to the bridge leading to the Gila Cliff Dwellings Visitor Center along the west fork of the Gila River.
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