La Nina vs. Western Snowmaggedon
Walking my dog at 6 a.m. this morning in Paonia, I could sense a presence in that exposed-fingers-will-break-off-any-minute-cuz-it's-so-friggin'-cold feeling:
A brutal minus-10-degrees-Fahrenheit kind of winter. A snow-makes-creepy-banshee-squeals-under-your-feet kind of winter. And it's a lot of snow for Paonia, HCN's home base in western Colorado, with more than a foot on the ground and the roads slicked in ice. Looks like the trusty Farmer's Almanac got it wrong for much of the West this year ... milder temperatures, my frostbitten nose.
Despite the physical pain, though, the cold and snow are a welcome departure from the disheartening predictions of expanding drought and a warmer/drier than average winter in the Southwest due to this year's La Nina weather pattern. In theory, the Northwest should be getting all the snow and cold, with equal chances of a colder/wetter or warmer/drier winter through the middle of the West, and warmer/drier conditions persisting across southern California, Nevada, Utah, and Colorado, and throughout Arizona and New Mexico. Obviously, the winter's not over yet, so all of that could still happen. But so far the season's epic storms have been tracking farther south, dropping feet and more feet of snow in the Sierra Nevada on the California-Nevada border, and in the Rockies through much of Colorado and Utah (check out this sweet real-time map tracking mountain snowpack throughout the West).
As you can see in the map above, the resulting snowpack in those states and northern Arizona is generally well over 100 percent of average (blues and purples), while in the Northwest and deep Southwest (particularly New Mexico) snowpack is right around or below average (red, orange, yellow, green). In the Sierra, several areas even report a whopping 200 percent of average snowpack. The depths in that mountain range are staggering, especially for so early in the season ... 80 inches, 98 inches, and on and on (refer back to that realtime map for more juicy details). Eastern California's Mammoth Mountain ski area is boasting a base of 10 to 17 feet. That's the epic kind of deep that draws pow'-hungry schussers in droves, and the scary kind of deep where folks braving ungroomed areas sometimes fall into tree wells or deep powder and actually suffocate. Late last month and early this month, snow even fell on Phoenix, Ariz. (sort of), and on the Las Vegas strip.
All this bodes well for average or better than average runoff this summer in the states lucky enough to be socked in (you can search yours here for the specifics); the National Resources Conservation Service says Colorado -- home of the headwaters of the Colorado River, which slakes the thirst of several Western states -- can actually endure a dry month without the state's water supply being much affected.
But of course, we wouldn't want you to get too optimistic about the promise of a lush, verdant summer on the horizon. There's always climate change's probable disproportionate impact on the West to think of (perhaps your frozen digits, at least, will rejoice over the prospect of warming), and the fact that the region's weather patterns are unpredictable in often unfriendly ways, regardless of climate change. Just last month scientists at the University of Arizona warned that the Southwest could be in for a 60-year drought, as apparently happened in the 12th century, according to United Press International:
"We're not saying future droughts will be worse than what we see in the paleo record, but we are saying they could be as bad," lead author Connie A. Woodhouse, a UA associate professor of geography and regional development, said. "However, the effects of such a worst-case drought, were it to recur in the future, would be greatly intensified by even warmer temperatures.
"Even without warming, if you had one of those medieval droughts now, the impact would be devastating," she said. "Our water systems are not built to sustain us through that length of drought."
Sarah Gilman is HCN's associate editor