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. NKP

    We eat meat, we destroy nature, we exploit resources and expect that nothing will happen to us. Every action has a reaction..Its Karma Stupid!

    January 14, 2011 at 9:38 am | Report abuse |
    • Matt

      It's not karma, it's called life. Animals eat animals and use resources for their survival, we are no different just more advanced

      January 14, 2011 at 9:48 am | Report abuse |
    • Catie

      I put people above animals, I am crazy that way.

      January 14, 2011 at 2:01 pm | Report abuse |
  2. Tony

    Are La Nina and El Nino even legally here? Sounds like wellfare sucking illegals to me! And Obummer is not suing them, instead of Arizona? Socilaism! I'm off to see what Beck wants me to think about all this.....

    (tongue firmly in cheek) 😉

    January 14, 2011 at 9:40 am | Report abuse |
  3. Will C

    Funny I explained it all.. & now its not here and my internet connectivity was active but no ability to repull interenet pages... & now its not here.. Right as i was putting on facebook. funny. well the liars are still with holding the truth.

    January 14, 2011 at 9:42 am | Report abuse |
  4. cougartino

    It's one of the affects of sin back in the garden.

    January 14, 2011 at 9:46 am | Report abuse |
    • Tony

      Hey, don't sin in my garden! Don't tread on my lawn either!

      January 14, 2011 at 9:47 am | Report abuse |
  5. Ryan

    Any thoughts on if the Icelandic volcano explosion could be contributing to these weird weather patterns?

    January 14, 2011 at 9:46 am | Report abuse |
  6. BusyPerson

    Does this make any sense to anyone? 11:11 ?

    January 14, 2011 at 9:46 am | Report abuse |
    • Matt

      No, does this make any sense to anyone? (_x_)========<:3 )~

      January 14, 2011 at 9:53 am | Report abuse |
  7. Will C

    Multiple earthly Human cleansing has happend more than once in our 400,000 yrs + of human history.. not the first & will not be the last in our godssssss (aliens=simply Not from earth)search for making the perfect Hybrid in the image of them! Just if your medium or low class find cover for you & your love ones... because you will never hear the truth until its too late for prep..trying times are near if u believe in End times no matter your religious sector. Remember u were informed.

    January 14, 2011 at 9:49 am | Report abuse |
    • Qwerty

      I bet you own stock in the aluminum companies. One can never have enough tin foil to wrap around their heads.

      January 14, 2011 at 11:30 am | Report abuse |
  8. okeefe

    Moon and Sun cycles have most effect yet no one wants to talk about that.

    January 14, 2011 at 9:50 am | Report abuse |
  9. Fred


    January 14, 2011 at 9:50 am | Report abuse |
  10. Greg

    The weather issues are all based on we the people of the world. We have over populated the earth along with the pollution and abusing Mother Nature. Now she is fighting back with Earthquakes, Tsunami's, Torrential rain and Flooding. We need to look at ourselves to correct what is happening before our kids have to be stuck with our bad decisions.

    January 14, 2011 at 9:51 am | Report abuse |
    • Bu11winkle

      If you are concerned about over population and think that is the cause of Global Warming, then why do you have children.

      January 14, 2011 at 10:32 am | Report abuse |
  11. Sndp

    I don't think we should be using the term 'Global Warming'. This sounds like a joke but a good number of people actually think Global Warming will actually warm up the entire Earth. I think the term 'Climate Change' should be stressed upon because predicting the environment to just keep warming up is kind of silly. Sure, that's what Greenhouse gases do but finally, like our bodies have antibodies to fight infection, the Earth has it's own measures to maintain it's equilibrium/balance. That could just be another cold wave or a flood or anything. (High) time to be mindful of our surroundings.

    January 14, 2011 at 9:52 am | Report abuse |
  12. Jugger

    Back in the 1970's all the climatologists were saying that we were heading into another ice age. Then Al Gore says we have massive amounts of "Global Warming". I am wondering which one got it right?

    January 14, 2011 at 9:52 am | Report abuse |
    • Matt


      January 14, 2011 at 9:54 am | Report abuse |
    • Cedar Rapids

      'Back in the 1970's all the climatologists were saying that we were heading into another ice age'
      No they didnt. A few suggested it in a few papers but it certainly was not the majority view point, not by a long shot.

      January 14, 2011 at 9:56 am | Report abuse |
    • johnp

      Thats sience! got to love it.

      January 14, 2011 at 12:22 pm | Report abuse |
  13. ann

    what about mentioning Europe where temperatures are abnormaly high? Instead of being around zero, theyre +15°C!!! Is that not crazy?

    January 14, 2011 at 9:53 am | Report abuse |
  14. please

    It's called "weather". There's nothing "bizarre" about it.

    January 14, 2011 at 9:53 am | Report abuse |
  15. ahhhh no climate change cause

    alas, since the earth comprises 3/4 water and the ocean temperatures obviously play a key role in the weather, can we finally stop publishing global warming theororists drivel, a greenhouse effect has always been condensation and precipitation at the top of the greenhouse and hot dry air in the bottom.......

    January 14, 2011 at 9:56 am | Report abuse |
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