Tuesday, October 16, 2012

La Nina Coming Back For 2012-2013?

Latest indications from the Equatorial Pacific are that something significant is happening. Let's get right to it.

This image is from the Climate Prediction Center, showing the latest Observed Sea Surface Temperature on top and sea surface temperature anomalies on the bottom. I outlined a region on the bottom image showing what I am so concerned about.

Do you see that blue area off of the South American coast circled in black? That is what very well could be a La Nina. This is the same phenomenon that was observed in the winters of 2010-2011 and 2011-2012. Now, this could indeed just be a quick cool down of a specific part of the ocean. However, I have reason to disprove this.

1) The water anomalies look wavy. The wavy look of this water anomaly suggests that this is an oscillation and not just an anomaly of cool water spontaneously bubbling up. Considering the ENSO phenomenon is an oscillation and oscillations tend to move in certain ways, this wavy pattern is no different.

2) This has been a sustained cooling. This appearance of cool water was not sudden. It has been developing in the last few weeks, more significantly this week and last week than in the past while. Given that this was not a sudden appearance-disappearance case, I find the case of a possible La Nina strengthened.

3) Global wind anomalies favor a La Nina. In this post published not too long ago, I highlighted regions that are showing typical La Nina characteristics. The observation of La Nina signals worldwide and this new development give me a stronger indication that this may be an emerging La Nina.


Underwater anomalies are still suggesting that El Nino-status waters remain present. It will take another few weeks to determine if these warm waters take down the new cold pool or are beaten by what could be a newborn La Nina.


1 comment:

Cameron Jourdan Fry said...

I appreciate the honest insight, Andrew. Such news saddens me. I do hope we can manage a neutral ENSO or slightly higher, but from the look of things, I would be very grateful if La Nina held off and we could enjoy a nice, wild winter weather season. Being a Nashville native, I'm glad that things are still somewhat looking up in the snow department. I take snow chases anywhere within 3-4 hours if storms hit relatively close to home. I look forward to tracking with you this year...