Last year a monster Kelvin wave (bubble of warm water) formed in the pacific and started heading eastward. Often times this is the forerunner of an El Nino event. The Kelvin wave surfaced and was followed by a bubble of cool water, which meant the end of any chance of a Super El Nino and we ended up with a weak, late El Nino. It's looking like this time, it's really going to be different.
Another Monster Kelvin wave has formed and this time it's looking like the real thing.
Notice how the cool bubble on the left side of the animation has stopped growing and even seems to be shrinking in the last couple of frames? There are many other factors that determine whether an El Nino will form and grow or not, but this is kind of an indicator that this monster Kelvin wave isn't going to dissipate as quickly as last year.
The models are becoming more and more confident that we are not only in a longer term El Nino, but it may end up being a really big one. How confident are they that our current weak El Nino is going to last awhile?
As you can see, there's a lot of confidence that this El Nino (red bar) is going to last for some time. But what about the intensity of this El Nino? The models are going crazy on this and some are indicating this one could be one for the record books.
One thing we should keep in mind is that at this time of year the models don't have a great record for accuracy for what happens later. But there are other factors that are supporting the models this year, which is why the confidence level is exceptionally high as of now.
One of the problems I have with trying to predict intermediate term weather patterns like El Nino, is that we don't live in the same climate that we did when many of these patterns were first noticed. What we expect, based on the patterns of the past, may not be what we get in our new climate of extremes.
But there's kind of a super long term El Nino that is called the Pacific Decadal Oscillation.
The Pacific Decadal Oscillation (PDO) is a pattern of Pacific climate variability similar to ENSO in character, but which varies over a much longer time scale. The PDO can remain in the same phase for 20 to 30 years, while ENSO cycles typically only last 6 to 18 months.
Like El Nino, it shifts back and forth from warm phases to cool phases and back again. Do you want to guess what phase the PDO is looking like it's entering now?
Michael Mann made some comments at
RealClimate.org back in Feb about why he thinks the PDO is changing and what we might be in for.
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Our conclusion that natural cooling in the Pacific is a principal contributor to the recent slowdown in large-scale warming is consistent with some other recent studies, including a study I commented on previously showing that stronger-than-normal winds in the tropical Pacific during the past decade have lead to increased upwelling of cold deep water in the eastern equatorial Pacific. Other work by Kevin Trenberth and John Fasullo of the National Center for Atmospheric Research (NCAR) shows that the there has been increased sub-surface heat burial in the Pacific ocean over this time frame, while yet another study by James Risbey and colleagues demonstrates that model simulations that most closely follow the observed sequence of El Niño and La Niña events over the past decade tend to reproduce the warming slowdown.
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This finding has potential ramifications for the climate changes we will see in the decades ahead. As we note in the last line of our article, Given the pattern of past historical variation, this trend will likely reverse with internal variability, instead adding to anthropogenic warming in the coming decades. That is perhaps the most worrying implication of our study, for it implies that the “false pause” may simply have been a cause for false complacency, when it comes to averting dangerous climate change.
So we're not only seeing a possible change of the PDO to a "warm" phase, but we may have a Super El Nino building on top of it. I'm sure you are all familiar with the normal El Nino problems the world faces, floods in Peru, droughts in Australia and the Ukraine... but when you add the weird patterns we've been seeing already, polar vortexes, massive fires in Siberia... it's really hard to tell what new catastrophe someone somewhere in the world is about to face.
There might be a tendency for the short term extreme patterns we've been seeing lately, to snap to the other extreme when the pattern breaks. Where I live, we had one of the driest, warmest winters I've ever seen. We were crushing record high temperatures by 10 degrees. Then in mid April the pattern snapped when we got 4 1/2 feet of snow out of a 2 day snowstorm, and it's been very wet and cool ever since.
I certainly hope that our new climate of extremes doesn't cause California to snap into a new pattern that brings as much misery as the current drought.