Wednesday, April 2, 2014

Record-Breaking Kelvin Wave Begins Hitting Ocean Surface

We continue to see the record breaking Kelvin Wave pushing to the surface, and anomalously warm waters are now appearing from the subsurface.

Water temperatures from the coast of Ecuador across the Equator are decidedly warmer than normal as of March 26th, as the chart above from the Climate Prediction Center shows. We see an arm of warmer than normal sea surface temperature anomalies (SSTAs) extending from about the 100W longitude line westward to roughly 140W. This noticeable warming comes as the strongest Kelvin Wave in history begins to push to the surface, in what could result in one of the stronger El Nino events on record.

The image here shows temperature anomalies on a depth by longitude layout on the bottom panel of this graphic, and the Kelvin Wave is clearly marked. As of March 31st, the water temperatures maxed out as high as 6.35 degrees Celsius above normal, confirming that this Kelvin Wave does appear to be the strongest one on record. This body of warm water provoked by the Wave is beginning to push to the surface, and this is already observed well by the extension of warm water to the surface around the 160E longitude line. I expect sea surface temperatures to continue to gradually rise in response to the agitated Kelvin Wave as it begins its trek to the surface.

We have been seeing the telltale El Nino signal in the Southern Oscillation Index for some time now. The chart above shows observed values of the Southern Oscillation Index averaged across a 30 day time period, shown since roughly December 2011. We have seen a roller-coaster pattern, as the atmosphere has been undecided on whether it will declare a La Nina or El Nino, until recently. As the chart shows, the SOI has completely tanked in recent days, to levels approaching -15. Values below -8 are considered resembling of an El Nino, while SOI observations above +8 are considered indicative of a La Nina. With the SOI being as low as it has been, there's little question in my mind that along with this Kelvin Wave, and taking into account the predicted conditions in the Equatorial Pacific in coming weeks, that we are entering into an El Nino.

A spread of global model projections of the El Nino-Southern Oscillation (ENSO) phenomenon all agree on at least a weak El Nino forming by August 2014, but even this seems a bit weak to me. I fear that model guidance is underestimating the current Kelvin Wave, and the El Nino may be a fair bit stronger by August 2014 than what is being shown here.

Updates on this unfolding situation will be provided on a weekly or bi-weekly basis, depending on the new information available.



Frank-o said...

A El-Nino is now a given!....Now I am really worried about the chance of a record breaking El-Nino as it can completely shut down winter for most of the 48 states.....especially the whole mid section and the east coast......A weak to somewhat moderate El-Nino usually means lots of gulf coast lows and lots of snow for us here in NorthWest NC. A Super Strong El-Nino can trigger Warm and I do mean record breaking warm air to surge into the mid section of the nation reaching from Texas all the way to the Dakota's and then to and from Maine to Fla. It can make for a very warm, with rain and more rain, and well, just lots and lots of just rain, on a 4 to 5day time table for weeks on end as front after front comes accross the lower half of the country and dips into the gulf and the lows just explode and come up the eastern seaboard.....don't like the sound of this at all....Hopefully if it does trun out to be a super El-Nino, it will go ahead and form and by December or January it be weaking some what.....So we can have a nice snow filled El-Nino winter!

Anonymous said...


We are desperate for rain here in Texas. What sort of pattern change should we look for in the models that may indicate that we are entering a regime more conducive to precip in the southern plains?

Oh, and Frank, with all due respect, bring on the super El Nino!

Anonymous said...

Frank-o, I agree with you about the winter. But for those of us in Texas, we really really need an El Nino to help with the drought situation. It is getting critical in places like Wichita Falls as well as the whole western/central parts of the state.