The specter of El Nino has been growing steadily the last couple of months and many of you have been asking about it. While I have been cautiously optimistic, I haven’t wanted to get too fired up yet…it is really easy to get hyped up on El Nino conditions, and then see the models fall apart as we finally move through what climatologists refer to as the “Spring Barrier”. (This barrier that they refer to is a hiccup in the long-range climate models…basically the computers have a tendency to over-estimate the intensity of large scale climate events because spring is such a dynamic season that it creates a lot of false-positives as localized weather/winds push ocean temps all over the place…so they use the long-range models as guidance as we move through spring but they prepare to adjust the baseline as we move into a more stable summer pattern. I know, I know…it gives me a headache to think about it as well.)
Now that we are moving closer to summer the models are getting adjusted and we are finally starting to see a clearer long-range picture of what is likely to happen over the next 8-12 months…and the good news (for those of you that crave an El Nino) is that the odds of us shifting from our current ENSO-Neutral to El Nino are looking pretty good.
You can check out the latest NOAA/Climate-Prediction-Center discussion update yourself…it is pretty dry reading, but it is compiled with new data early each month.
Here is the short-version.
1. NOAA/CPC have issued a El Nino Watch, which is activated when conditions are favorable for the development of El Niño conditions within the next six months.
2. ENSO-Neutral conditions are expected to last through the end of spring…however large pockets of warm surface and sub-surface water are currently forming along the equator, in particular near Mainland Mexico/Central America, as well as parts of northern South America. We have also weak low-level winds (blowing against the grain of the normal trade-winds) in the Western Pacific, which is part of the cause, and a symptom, of the shift to a dominant El Nino pattern.
3. If the current wind and water temp pattern continues we will move into an active El Nino by summer of 2014…and will likely see these warmer El Nino conditions continue into Fall and through Winter of 2014-2015.
Just to warn you, this is the weather-nerd section…so if talking about atmospheric/oceanographic related phenomena makes you sleepy…this you may just want to skim through this section.
Just What Is El Nino?
For those of you just starting to get a grasp that El Nino can be a significant influence on our surf…but aren’t exactly sure what all the technical terms stand for here is a quick breakdown.
The Acronym ENSO, which stands for El Nino / Southern Oscillation, describes the two main atmospheric and ocean related shifts that occur in the Pacific when we move out of the ENSO-Neutral Phase and into either a warm El Nino episode (or a colder La Nina one). Keep in mind that these shifts are closely linked but over the last several cycles we have found that they are not mutually exclusive.
1. The El Nino – During El Nino episodes we generally see the trade winds along the Eastern Equatorial Pacific begin to weaken, or even stall out altogether. Without the winds to maintain circulation (and large scale upwelling) warm water starts to pool along the coastlines of Mainland Mexico, Central America, Peru, and in extreme years will extend out and up to include most of the NE Pacific tropical storm region as well as the waters around portions of Southern Baja and the Sea of Cortez. For the most intense El Nino this ocean warming doesn’t just occur on the surface, but will extend down nearly 200-300 meters into the deeper ocean.
2. Southern Oscillation – The second major shift is a large, dry area of high pressure that forms over the western side of the Equatorial Pacific causing reduced rainfall and even drought in some areas. This ridge of pressure usually ends up affecting as far west as Indonesia and encompasses the regions of Papa New Guinea, portions of Australia, and the Philippines. Without the warmer water and associated moisture being pushed along by the trade winds (the ones that weakened over in the eastern half of the Pacific) this cascades into the monsoon regions and can trigger drought across an even bigger area beyond just the regions stifled by the high-pressure.
These are obviously very simplified versions of what occurs during an El Nino (or ENSO: El Nino as the un-cool kids like to say). If you like to geek out on this stuff I would highly recommend checking out the Climate Prediction Center’s website and looking up these terms on the web (Wikipedia, ect,).2014, El Nino, el nino 2014-2015, el nino breakdown, Tropical Swell, winter surf