How La Niña May Affect Your Ski Vacation

Planning a ski vacation this winter? You may want to consider heading to the Pacific Northwest, which stands to benefit the most from the periodic climate cycle known as La Niña. Ski areas such as Mt. Baker in Washington and Whistler Blackcomb in British Columbia both set their records for most snowfall in a single season during a strong La Niña episode in 1998-1999, which bodes well for the ski season that is just getting underway.

According to Whistler Blackcomb’s Breton Murphy, La Niña typically adds about 40 additional inches of snow to the mountain’s average annual total of 33.6 feet. During the 1998-1999 season, when an unusually strong La Niña event occurred, the mountain racked up a whopping 666.5 inches, or about 55 feet of snow.

Mt. Baker also recorded an epic snowfall total during that season, to the tune of 1,140 inches of snow, or 95 feet. According to some, that set a new world record for the most snowfall ever recorded in a single winter, anywhere on the planet. The ski area recently released a statement on the upcoming La Nina winter, saying:

In the past 15 winters we have had 4 La Niña seasons and have on average received 778 inches of snow during those seasons. This is a little over 100 inches more than our average annual snowfall.

The La Niña pattern generally means below average temperatures coupled with average or above average precipitation and for Baker this generally equates to more snow than average. In addition, La Niña can affect the position of the jet stream and point it straight at Baker, a situation that can cause the storms stacked up in the Pacific to bring their moisture laden goodness directly to us as system after system is propelled our direction by this “storm superhighway.”

The statement also noted that La Niña winters tend to be colder than average with a lower freezing level, which results in more powdery snow. In other words, skiers’ gold.

According to the National Oceanic and Atmospheric Administration (NOAA) and the International Research Institute for Climate and Society (IRI), La Niña is expected to last through Spring 2011, and be a strong episode. La Niña is a source of natural climate variability characterized by an area of colder than average waters in the equatorial Pacific Ocean. It’s essentially the opposite of El Niño, which features warmer than average waters.

During a La Niña winter, the jet stream tends to get pushed northward, steering storms into the Pacific Northwest and leading to colder and wetter conditions there, while robbing the Southwest of precipitation. The northern Rockies and Ohio Valley are also expected to be wetter than average this winter, while warmer and drier than average conditions affect parts of the South and southeastern U.S.

Sea surface temperature anomalies in the equatorial Pacific Ocean. Blue colors indicate cooler-than-average conditions, a hallmark of Liña. Credit: IRI.

According to Tony Barnston, lead climate forecaster at IRI, skiers’ best bet is to head to the Pacific Northwest or northern Rockies for the highest likelihood of very snowy conditions. He says areas located in the Southwest or Southern Sierras may receive less snowfall than normal this season due to La Niña-influenced weather patterns. However, resorts in far northern California could receive more snowfall than usual since they will be located closer to the jet stream.

In the Northeast, Barnston says, the picture is not quite as clear. Ski areas in northern New England are likely to experience cooler than average conditions, but near normal or below normal precipitation. “So you wouldn’t necessarily get more snow,” he says,  “It might if anything [unusual] be a little less than average.” Ski areas in southern New England can expect milder and drier than average conditions — not exactly a recipe for a stellar ski season there.

Interestingly, La Niña can also affect global temperatures, and may prevent this year from becoming the warmest year in the instrumental record. According to NASA, October was the third warmest such month on record. Barnston says there is a time lag between when La Niña conditions set in and when a cooling signal appears in global temperature data. He noted that La Niña is “Probably only now beginning to dampen the warming” related to both manmade climate change and an El Niño event that ended late last spring. “The question is whether it will cancel out enough of that warming in the last two months to make 2010 not be the warmest year.”

Here are our projections for where to find the most snow during the the 2010-2011 ski season. Keep in mind these are based on typical La Niña-related weather patterns and weather outlooks for this winter.

• Posted in Climate, Society, Weather, Projections, Snow & Ice, States of Change, United States