Thursday, February 3, 2011

Bastardi: Three of Next Five Winters Could Be as Cold or Colder

Bastardi: Three of Next Five Winters Could Be as Cold or Colder

Feb 3, 2011; 7:21 AM ET

This winter is on track to become the coldest for the nation as a whole since the 1980s or possibly even the late 1970s. According to AccuWeather.com Chief Long Range Forecaster Joe Bastardi, three or four out of the next five winters could be just as cold, if not colder.

He is worried that next winter, for example, will be colder than this one.

Bastardi adds that with the U.S. in the middle of one of its worst recessions in its history and the price of oil in question, he is extremely concerned about the prospect for more persistent cold weather in the coming years putting increased financial hardship on Americans.

"Cold is a lot worse than warm," Bastardi said, "and that's why your energy bill goes up during the winter time: because of the fact that it takes a lot to heat a house."

While there are many different factors that are playing into Bastardi's forecast, one of the primary drivers is La Niña and the trends that have been observed in winters that follow the onset of a La Niña.

Hear more from Bastardi on his forecast, La Nina and the implications that more cold winters could have on energy demands and the economy, click on this video.
http://www.accuweather.com/blogs/news/story/45220/bastardi-three-of-next-five-wi.asp

Current La Nina Signals More Cold Winters Ahead

La Niña occurs when sea surface temperatures across the equatorial central and eastern Pacific are below normal. La Niña and its counterpart, El Niño, which occurs when sea surface temperatures of the same region are above normal, have a large influence on the weather patterns that set up across the globe.

The current La Niña, which kicked in this past summer, is unprecedented after becoming the strongest on record in December 2010. Bastardi thinks this La Niña will last into next year, though it will be weaker, and will not disappear completely until 2012.

According to Bastardi, studies over the past 100 years or so show that after the first winter following the onset of a La Niña, the next several winters thereafter tend to be colder than normal in the U.S.

He says the first winter during a La Niña tends to be warm. The next winter that follows is usually less warm, and the winter after that is usually cold.

"There's a natural tendency for that to happen because of the large-scale factors," Bastardi commented. "What's interesting about what we're seeing here is that [the current La Niña] is starting so cold."

Temperatures this winter so far are averaging below normal across much of the eastern two-thirds of the country.

He adds, "If the past predicts the future, then the first year La Niña is warmer than the combination of the following two."

He said that with the exception of the winters of 1916-1917 and 1917-1918, the first year of every moderate or stronger La Niña available for study has featured a warmer-than-normal winter from the Plains eastward. This winter, it has been colder than normal.

Taking a look at one of the exceptions, the La Niña winter of 1916-1917, colder-than-normal conditions were observed across the northern part of the Plains and East (not the South). Bastardi said that never before have colder-than-normal conditions been observed across the South during a first-year La Niña winter, as has been the case this winter.

If this winter, which has been colder than normal across the eastern two-thirds of the country, is historically supposed to be the warmest of the next three winters for the U.S., according to Bastardi, we have some frigid times ahead.

Bastardi: Shift to Colder Climate Predicted Next 20-30 Years

Bastardi thinks that not only will the next few winters be colder than normal for much of the U.S., but that the long-term climate will turn colder over the next 20 to 30 years.

"What's interesting about what we're seeing here is that [the current La Niña] is starting so cold," said Bastardi, "and it's coinciding with bigger things that are pushing the overall weather patterns and climate in the Northern Hemisphere and, in fact, globally over the next 20 to 30 years that we have not really dealt with, nor can we really quantify."
"That ties into a lot of this arguing over climate change," he added.

Bastardi has pointed out that the Pacific Decadal Oscillation (PDO), which is a pattern of Pacific climate variability that shifts phases usually about every 20 to 30 years, has shifted into a "cold" or "negative" phase.

Over the past 30 years or so, according to Bastardi, the PDO has been "warm" or "positive."
This change to a cold PDO over the next 20 to 30 years, he says, will cause La Niñas to be stronger and longer than El Niños. Bastardi adds that when El Niños do kick in, if they try to come on strong like they did last year, they will get "beaten back" pretty quickly.

"When you have a cold PDO and lots of La Niñas, when El Niños do come on, you generally tend to have cold, snowy weather patterns across the U.S.," Bastardi said. "That's what we saw in the 1960s and 1970s."

In Summary

Overall, Bastardi is predicting three or four of the next five winters to be colder than normal for much of the U.S., based on trends observed in La Niñas throughout history.

He is concerned that, amid the current recession, more colder-than-normal conditions in the winters ahead will put extra financial strain on families in the form of higher heating bills.

Bastardi is also predicting the long-term climate to turn colder over the next 20 to 30 years with global temperatures, as measured by satellite, returning to levels they were at in the late 1970s.

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By Heather Buchman, Meteorologist

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