Friday, May 9, 2014

Dangerous progress toward strong El Nino continues as extreme Kelvin Wave rises in Eastern Pacific

By Robert Scribbler via robertscribbler.wordpress.com, 8 May 2014

It’s happening. The most powerful sub surface warming of the Pacific Ocean on record is continuing to progress into the Eastern Pacific even as it rises toward the surface. As a result, risks for the emergence of El Nino during 2014 are spiking together with the potential for a host of global weather extremes.

Over the past month, trade winds remained weak even as west wind back bursts continued to push against the trades along the Equatorial Pacific. Moderate west winds emerged during mid-to-late April northeast of the Solomon Islands while cyclonic lows produced sporadic west winds in the Central Pacific. By May, consistent west winds were blowing over a large section of the Eastern Pacific.

Upper level easterlies had also emerged reinforcing a general pattern toward El Nino development.

The strong Kelvin wave that, in March, featured the highest sub-surface temperature anomalies on record entered its upwelling phase and began to push more and more of its heat potential toward the surface in the Eastern Pacific. This propagation is clearly visible in the sequence below:


(Kelvin Wave monitoring by NOAA. Image source: Climate Prediction Center.)

As of May 3, 2-3 C above average water temperatures had hit the surface of the Eastern Pacific and 3-6+ C above average temperatures lurked not far below.

The result of this rising warm water pulse was above average sea surface temperatures across the entire Equatorial Pacific with anomalies for the broader region hitting +.62 C on May 8th, 2014. It is worth noting that for El Nino to be declared, Equatorial Pacific water temperatures in the mid to eastern Pacific must remain above +.5 C for two months running. And, at this point, conditions appear primed for just such an event.

May 7 SST anomaly

(May 7, 2014 Sea Surface Temperature anomaly map shows Pacific Ocean looking more and more like an El Nino. Image source: NOAA ESRL.)

These clear ongoing trends have resulted in yet one more upgrade of El Nino potentials by the Climate Prediction Center (CPC) this week. Chances for El Nino in the current three month period of May, June and July have now been adjusted to about 55% with probabilities continuing to rise throughout the summer and fall. Peak chances for El Nino, according to CPC, are now just shy of 80% by October, November and December of 2014.

All values now show a very high degree of certainty that El Nino will emerge exceeding even the high confidence predictions provided last month by both NOAA and Australia’s Bureau of Meteorology (BOM).

Continue to the full article,
http://robertscribbler.wordpress.com/2014/05/08/dangerous-progress-toward-strong-el-nino-continues-as-extreme-kelvin-wave-rises-in-eastern-pacific/

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