Forecaster: Two phenomena responsible for world's bizarre weather
A graphic outlining sea temperature anomalies the first week in January shows drops in the Pacific as air temperatures rise between the U.S. and Europe (continents in gray). La Niña and the North Atlantic Oscillation are to blame, an expert says.
January 13th, 2011
03:35 PM ET

Forecaster: Two phenomena responsible for world's bizarre weather

The catastrophic weather events taking place across the globe – from Brazil’s and Australia’s flooding to the Eastern United States’ heavy snowfall – have two likely explanations.

Tony Barnston, lead forecaster at Columbia University’s International Research Institute for Climate and Society, said two phenomena – La Niña and the North Atlantic Oscillation – are likely responsible for the patterns we’re seeing.

Though La Niña is different every time, it can be simply defined as a drop in water temperature in the eastern and central tropical Pacific Ocean. This particular La Niña appeared in July, Barnston said, and will last through spring.

During La Niña, there is less rainfall in the tropical Pacific and a horseshoe pattern of warm water typically forms in the North Pacific, the coast of Southeast Asia and the seas around Indonesia and Australia (check out the graphic above).

In this case, though, “the whole globe looks to be compensating,” Barnston said, noting that it’s difficult to determine if  La Niña spawns individual weather events.

While Southeast Asia and Australia can typically expect warmer oceans and more rainfall during La Niña, the affected area stretches farther west this year and includes Sri Lanka and the southern tip of India, Barnston said.

There is presently a massive rescue operation under way in Sri Lanka to save victims of flooding that has already killed at least 13 people. Floods have killed another 40 people in the Philippines, and Australia has been inundated with deadly flooding reportedly estimated to cover an area the size of France and Germany combined. To the east of La Niña, South America's north coast has been slammed with rain, and hundreds have been killed in Brazil's flooding and mudslides.

La Niña usually means warmer temperatures in the United States, particularly the Southeast, but this year the North Atlantic Oscillation is trumping La Niña.

Since November, we have been in the negative phase of the North Atlantic Oscillation, Barnston said, meaning that air temperatures between the eastern U.S. and Europe will drop. This causes temperatures to rise in places like northeast Canada, Greenland and Iceland, as the mercury drops on thermometers in the eastern U.S.

Weather experts call it a see-saw pattern, and it will eventually affect water temperatures, though that’s a secondary effect, Barnston said.

So while La Niña would normally mean dryer, warmer weather for folks in the southern United States, “the North Atlantic Oscillation has superseded the La Niña” this year, bringing El Niño-like winter temperatures and snow to the Southeast, he said.

CNN meteorologists reported earlier this week that snow was present in every U.S. state but Florida.

Though La Nina typically lasts until April or May, the North Atlantic Oscillation can move from a negative to positive phase mid-winter. Barnston said the Southeast “could be warmer and dryer than normal later this year if the North Atlantic Oscillation ceases and desists.”

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Filed under: Australia • Brazil • India • Indonesia • Philippines • Sri Lanka • Tropical weather • U.S. • Weather • Winter weather
soundoff (963 Responses)
  1. Bruce Rubin

    Its amazing how accurate Government controlled experts can be in explaining the massive world flooding as anything other than global warming but cant predict when it will rain accurately

    January 13, 2011 at 6:01 pm | Report abuse |
  2. John

    Ok kiddies here's the facts ... at one point in it's history th earth was completely under about a mile of ice. And during another period it was so hot there weren't any polar ice caps. Are we so egocentric to think that we as a race oiur the driving force for a global warming. Well ask al gore he'll assure you we are, even if it ain't so. Yes the earth is warming and yes our green house gas emissions are involved. But sadly all we've done is to maybe stop the slide into the next ice age. wake up people it isn't all about us.

    January 13, 2011 at 6:01 pm | Report abuse |
    • gremlin

      Actually whether the entire earth was ever completely covered is a generally accepted but still contested conjecture. And i don't think it was over a mile everywhere. There has never been a question whether global climate change patterns are natural–they are. The question has been whether greenhouse gases and other man-made factors could turn a small perturbation into a large one. And there is a large body of scientific knowledge that points to these factors having a significant impact. Regardless of that answer, it seems like a logical that people would want to reduce emissions just because in general they are pollutants which, you know, pollute.

      January 13, 2011 at 6:43 pm | Report abuse |
    • gremlin

      I think waaaaay too many people on this forum have watched "The Core"

      January 13, 2011 at 6:49 pm | Report abuse |
    • Cedar Rapids

      'Are we so egocentric to think that we as a race oiur the driving force for a global warming. '
      Are we so egocentric as to think that what we do has no effect on the planet?

      January 13, 2011 at 10:05 pm | Report abuse |
  3. maverick

    prepair for the return of zenu, king of the galaxy.

    January 13, 2011 at 6:06 pm | Report abuse |
  4. John

    OMG it's not the end ot the world people, it's just a minor blip in our planets evolution. Ya'll need to calm the heck down and relax!!!

    January 13, 2011 at 6:11 pm | Report abuse |
    • brandon


      January 13, 2011 at 7:00 pm | Report abuse |
  5. PartisanSheep

    @John: it has nothing to do with ego. Humans already know that CO2 traps heat in the atmosphere. You can do a simple experiment yourself at home. Take 2 empty pop/soda bottles have one filled with the air we breathe. Then throw some baking soda and vinegar together in the bottom of the other bottle. Cover them. Let them both sit in the sun for 2 hours then take the temperature of both. The CO2 bottle will have a higher temperature. When humans turn green lands into parking lots or malls they remove the natural co2 filters (plants). Then with all the cars or coal burning we add to the co2 content of the atmosphere.

    January 13, 2011 at 6:13 pm | Report abuse |
    • Tony


      Come now, you know the deniers aren't interested in logic and facts, and they certainly won't do the experiment you propose. Why? Well they are complacent with the world as it is, even if its on its way to hell in a hand basket. Actually acknowledging a problem compels one to do something. That unfortunately is way to much to ask of some.

      January 13, 2011 at 7:08 pm | Report abuse |
    • engineer123

      The experiment in the bottle is a neat trick but it leaves out one thing. The bottle doesn't have clouds. Clouds have a stronger affect on our atmosphere then CO2. The computer models they use to predict global warming are not accurate because they cannot replicate clouds. Also the computer models neglect the affect of the sun. The sun drives everything and it is due for a downturn which means it will get colder. The suns 11 year cycle is very low so far.

      January 13, 2011 at 9:41 pm | Report abuse |
    • Cedar Rapids

      'The computer models they use to predict global warming are not accurate because they cannot replicate clouds. Also the computer models neglect the affect of the sun. '
      yeah because you are the only one smart enough to take those sort of variables into account when doing computer models, ok then.

      January 13, 2011 at 10:06 pm | Report abuse |
    • Tony

      @Engineer – you are absolutely correct about the solar cycles. We should be cooling, and should have been for the past century. So why have we in fact been warming at the fastest rate in the history of our planet?

      and re: the models....they have been used to replicate the climate of the past century and have done a very good job. This proves that they are in fact able to model climate.

      January 13, 2011 at 10:54 pm | Report abuse |
    • baby jeebus

      what? water vapor is a potent greenhouse gas? Shut it!! oh and the computer models are the most accurate models known to man. The simulation are tried an true and accurately predict warming in the range of 2-18 degrees. I'm going to pray to baby jeebus that it's in the 2 range. It would be quite nice of the average temp in january/february goes from 35 to 37 degrees.

      January 13, 2011 at 11:10 pm | Report abuse |
  6. tonyprado

    Al gore turns over in suntan booth

    January 13, 2011 at 6:15 pm | Report abuse |
  7. tonyprado


    January 13, 2011 at 6:16 pm | Report abuse |
  8. bill

    They forgot Dr Evil....for a meeeeelion dollars you can have sunny and 72*

    January 13, 2011 at 6:20 pm | Report abuse |
  9. bill

    We spend $300h for copter crews to chop down pot plants in the US every summer X 30 states that adds up.

    I guess with an alleged CO2 surplus that is a good policy. We all know most pot plants grow up to rob banks and sodomize children.

    January 13, 2011 at 6:23 pm | Report abuse |
  10. Jrad

    I like how the graphic is so stretched and distorted that I can barely decipher it.

    January 13, 2011 at 6:23 pm | Report abuse |
  11. Phillydon

    3rd phenomena:: The government, be it US, Russia, or PRC are attempting to control the weather.

    January 13, 2011 at 6:24 pm | Report abuse |
    • BuzzMann

      And they are doing it fro the moon,ohh,wait,we never really went there either.

      January 13, 2011 at 9:10 pm | Report abuse |
  12. Ravenna

    Wow I am astounded by the comments here. Too many people think the end is nigh because of the weather. Get a life folks.

    January 13, 2011 at 6:27 pm | Report abuse |
  13. scott

    are you co2 "experts" all aware that a volcano eruption spews 10x the amount of co2 into the atmosphere than humans have generated in the last 30 years?

    January 13, 2011 at 6:30 pm | Report abuse |
    • Benny V

      Then why are atmospheric CO2 levels currently higher than EVER recorded? Or are you implying that this volcano business is a new phenomenon... -_-

      January 13, 2011 at 6:40 pm | Report abuse |
    • Ray

      The problem is not only generation, the natural CO2 filter of our earth (the trees) are cut down by us, which leads to this problem of excess CO2 in our atmosphere.

      January 13, 2011 at 6:50 pm | Report abuse |
    • Pull the other

      Hey "expert", do you know that you are utterly wrong? Volcanos produce a tiny fraction of the CO2 that humans do. Do a quick google search and educate yourself.

      January 13, 2011 at 9:22 pm | Report abuse |
    • baby jeebus

      Benny V: CO2 levels are not at an all time high. in fact, CO2 levels were so high (45% of the atmosphere) millions of years ago the effin sky was red. Google it.

      January 13, 2011 at 11:27 pm | Report abuse |
  14. Jibba Tokez

    Easy to slap the word La Nino on the faces of ingorance! Not the end of the world or human race but the planet does change its facial features time to time. Why is it so hard to understand that?

    January 13, 2011 at 6:31 pm | Report abuse |
  15. Michael57

    Poison from the sky kills birds? Who is next? The magnetic poles are shifting causing the weather confusion and death from the skies.

    January 13, 2011 at 6:33 pm | Report abuse |
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