La Nina Round Two

<b>La Niña is Back</b> OK, sports fans, La Niña is back. This is good news for some mountains and bad news for others. And it’s actually really bad news for meteorologists, who now must answer the barrage of requests for a six-month snow forecast. Just remember that a seasonal forecast is less important than following each individual storm during the winter. That said, here’s the scoop on La Niña. Water temperatures in the central Pacific Ocean are much colder than average, which is the definition of La Niña. Those temperatures can affect weather patterns across the globe, and that’s why La Niña is important. For North America, La Niña has some predictable consequences for snow during the winter: it snows a lot. (Joel Gratz)

This season vs. last season Last season, La Niña was moderate to strong, which translated into forecasts of much above average snowfall for the northern part of the U.S. and into Canada. For the most part, this forecast came true with nearly 150 percent of average snow falling in the Pacific Northwest and record seasons extending into Utah and northern Colorado. However, this season’s La Niña is only about 60 percent as strong as last season. The tough part about this fact is that the forecast for snow isn’t as simple as lowering last season’s predictions by 1/3rd. When La Niña is strong, its affects on snowfall are rather predictable. When La Niña is weaker (or non-existent), it’s affects on our wintertime weather patterns are less certain, so the outlook for this season is much less confident. But let’s give it a go anyway…

<b>BC and Alaska </b> British Columbia and Alaska often do well in La Niña years, with 10-25 percent above average snowfall. Even with a weaker La Niña this season, it still looks like these areas will experience plenty of powder. (Alyeska Ski Resort)

<b>Pacific Northwest </b> The Pacific Northwest (Washington and Oregon) also does very well in La Niña years, and that trend should continue for the winter of 2011-2012. This region is one of the more predictable when it comes to La Niña, so my confidence is high that it’ll be another great snow season. (Alyeska Ski Resort)

<b>Pacific Northwest </b> The Pacific Northwest (Washington and Oregon) also does very well in La Niña years, and that trend should continue for the winter of 2011-2012. This region is one of the more predictable when it comes to La Niña, so my confidence is high that it’ll be another great snow season. (Alpine Meadows)

<b>Northern Rockies </b> The northern Rockies (Idaho, Montana, Wyoming) do very well in La Niña seasons. It happened last season, and it should happen again this year. Expect above average snowfall, perhaps between 110-130 percent of normal. (Bridger Bowl)

<b>Utah and Colorado</b> Utah and Colorado are much like Tahoe—on the fence. Northern Utah (where most of the resorts are, in the Wasatch) and northern Colorado (roughly north of Aspen) normally do well in La Niña years. Last season snowfall topped 150 percent of average, but I’m not overly confident about a repeat this year. The smart money would wager for an above-average season for these areas, but likely not as spectacular as last season. (Jack Affleck, Vail Resorts)

<b>Southern Areas</b> Southern areas, like lower lattiude California, Arizona, southern Colorado, and New Mexico often are not favored for big snow seasons during La Niña. However, last season proved that La Niña is not perfectly predictable as Mammoth and Wolf Creek had above average seasons. We’ll see what happens this year, but the general forecast is for less snow the further south you go in the U.S.

<b>Southern Areas</b> Southern areas, like lower lattiude California, Arizona, southern Colorado, and New Mexico often are not favored for big snow seasons during La Niña. However, last season proved that La Niña is not perfectly predictable as Mammoth and Wolf Creek had above average seasons. We’ll see what happens this year, but the general forecast is for less snow the further south you go in the U.S. (Jay Peak Resort)