When the National Oceanic and Atmospheric Administration released information in early October stating that the water temperatures in the Pacific Ocean were cooler than average, powder fiends across the northern tier of the United States rejoiced. What do the ocean temps in the Pacific have to do with getting fresh tracks on the hill? “La Niña means that water temps in the Central Pacific Ocean are below normal,” says Joel Gratz, a Colorado meteorologist who operates opensnow.com. “This matters because it’s a big area. Water temperatures in that area can change weather across the world.” The cold temperatures in the Pacific essentially supercharge the trade winds with cold air and moisture, resulting in winters like we saw last year. When there’s warm water in the Pacific, El Niño dominates, creating more storms in the Southern U.S. “If there’s no El Niño or La Niña, it’s very hard to make any type of seasonal prediction for the winter,” Gratz says.
Why is La Niña such a big deal? Winter Park, Colorado received 112 more inches in 2010–11 than the previous season’s El Niño winter. Jackson Hole, Wyoming piled an additional 250 inches of snow on a copious 500-inch annual average. In Utah, Snowbird crushed the previous snowfall record of 688 inches with 783 inches of Wasatch white stuff. The Pacific Northwest typically sees the most snow during La Niña, and this last visit was no exception. Mt. Bachelor set a new snowfall record with 665 inches in Oregon. Tahoe’s Squaw Valley saw its previous record annihilated, piling up a mind-blowing 810 inches of snow.
NOAA’s update, however, indicated La Niña is weaker this year than in 2010, which may account for Wolf Creek‘s early snowfall. Located in southern Colorado, the resort doesn’t typically benefit from La Niña. “I don’t believe that it’s a full La Niña year going on,” says Wolf Creek’s Rosanne Pitcher. “Last year was scantier than other years as far as moisture. This year we’ve had the moisture and the cold weather.” With 68 inches of snow already this season, Wolf Creek is currently 95 percent open.
Still, this winter is already showing promise farther north. Snow hammered the East Coast this past weekend. Stratton Mountain in Vermont accumulated nearly 18 inches at the summit. “We often get snow this time of year,” says Stratton’s Meryl Robinson. “But we don’t always get this much of it, so it’s pretty exciting.” La Niña brought Stratton nearly record-setting snow last year, and Robinson is hoping for a repeat. —Gavin Gibson
Snowflake image by Kelly Gorham. Click on the image below to launch a photo gallery of La Niña in action last winter and early-season shots from this year.