Third Warm Kelvin Wave to Raise Extreme El Nino by Fall?

More fuel for El Nino’s fire and a record hot 2015 on the way…

Last week, a set of climate models predicted the emergence of a large and moderately strong westerly wind burst running against the trades associated with an eastward propagating cloudy and rainy phase of the Madden-Julian Oscillation (MJO). And, over the past few days a moderate strength, but very wide-ranging, westerly wind pattern appeared.

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(A strengthening westerly wind burst over the Western Equatorial Pacific could produce a third warm Kelvin Wave and further heighten an El Nino that already has a potential to be very intense come Fall. Image source: Earth Nullschool.)

Today, 20 to 35 mile per hour westerly winds are prevalent along a 2,500 mile stretch of ocean running from just east of the Philippines, across an equatorial zone just north of New Guinea, and on eastward for hundreds more miles in the direction of the Date Line. The winds are associated with numerous low pressure systems developing both north and south of the Equator — their cyclonic wind patterns joining in a daisy chain like feature to drive a large synoptic westerly wind back-burst (WWB).

Over the next few days, winds within the zone are predicted to strengthen to near gale force intensity. But it’s the size of the zone that may have the greatest impact.

Strong, long-fetch westerlies in this region of the world have a tendency to push warm surface waters, now topping off at 31 degrees Celsius (and 1-2 C above the already hotter than normal 1979 to 2000 average), downward and eastward. This heat pump action generates what, in meteorological parlance, are known as warm Kelvin Waves. And warm Kelvin Waves are high energy fuel for strengthening El Ninos.

Two Warm Kelvin Waves

(Warm water propagation through the upper 300 meters of the central and eastern Equatorial Pacific serves as oceanic fuel for El Nino events. In the above graph by NOAA, not one but two warm Kelvin Waves are indicated — one peaking during April and May, and a second ongoing now. Will a significant westerly wind burst, now lighting off in the Western Pacific, generate a third warm Kelvin Wave by August? Image source: NOAA’s Climate Prediction Center.)

During mid-March, the Strongest Madden Julian Oscillation on record drove an extreme westerly wind burst (WWB) and produced a very strong Kelvin Wave. This Kelvin Wave ensured the progression to El Nino during 2015, an El Nino event that would have probably reached moderate strength by summer on the force of this single Kelvin Wave’s heating alone. An El Nino ensuring, when combined with the greenhouse gas heat forcing produced by humans, that 2015 would march into the record books as yet one more hottest year in the global climate record.

By early May, a second, albeit somewhat weaker, WWB generated another warm Kelvin Wave, heightening the potential for strong El Nino yet again. This time El Nino model forecasts picked up the doubled Kelvin Wave signal and began to produce some rather extreme predictions for El Nino come Fall. Late spring is an uncertain time for El Nino models due to an ocean tendency to cool down by September. So the impact of strong Kelvin Waves during spring can be somewhat muted. However, as June arrived, the model consensus for a strong El Nino emerging by Fall had solidified, if not along a range quite so extreme as some of the May numbers indicated.

Meanwhile, in the Central Pacific, anomalous warm sea surface temperatures were continuing to build. By mid-May, Central Pacific sea surface temperatures exceeded the moderate El Nino threshold of 1 C above average. By Monday, June 22, NOAA’s weekly El Nino statement had indicated that the Central Pacific region had warmed to a 1.4 degree Celsius positive anomaly. A level just 0.1 C short of strong El Nino intensity.

Adding a third significant Westerly Wind Burst on top of an already warming Equatorial Pacific throws yet one more variable into the dynamic El Nino forecast. A variable that could heighten the already strong potential for a major El Nino event late this Summer through to Fall. And one that could further heighten extreme global record hot temperatures during 2015. For the late June WWB is likely to produce an extraordinary third Warm Kelvin Wave, giving the currently strengthening El Nino yet one more shove toward increasingly extreme conditions.

Links:

NOAA’s Climate Prediction Center (Please support public, non-special interest based, science like the quality research and data provided to us daily by NOAA.)

NOAA’s weekly El Nino statement

Strongest Madden Julian Oscillation On Record

Madden-Julian Oscillation

Earth Nullschool

 

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Steaming Equatorial Pacific Sees Winds Blowing Toward Monster El Nino

Last year, we raised a warning that the 2014-2015 El Nino could develop into a monster event. And, unfortunately, there is some indication that conditions may well be continuing in that direction.

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All across the broad belt of the Equatorial Pacific, sea surface temperatures are running in the hot-to-extraordinarily hot range. Starting just north and east of New Guinea, 1 C + above average temperature anomalies run uninterrupted to a zone near the date line where they encounter a hot pool in the range of +2.6 to +3.1 C above average. Running eastward, these high heat anomalies gradually taper off to +1.4 to +1.7 C along a 5,000 mile stretch before they again spike to +3 to +4 C above average just off the west coast of South America.

A massive zone of above average sea surface temperatures encompassing almost the entire width of the Equatorial Pacific:

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(Pacific Ocean showing extreme heat anomalies across most regions. Image source: Earth Nullschool.)

Hot equatorial waters in a Pacific Ocean that, from Arctic north to Austral south, from East Asian shores to the west coasts of the Americas is a morass of record high temperatures. An ocean zone featuring few and dwindling pools of lower than average readings. Oceans undergoing rising rates of heat-related sea creature die offs in waters that, when they warm, lose vital oxygen and host toxin-producing microbes that thrive in hot water.

It’s a freakishly hot Pacific. A strange ocean. One that we aren’t quite accustomed to. One in the grips of what is already a moderate strength El Nino. An El Nino that, combined with an extraordinary human greenhouse gas heat forcing, has pushed global surface temperatures into record high range for 2014 and the first three months of 2015 thus far. An El Nino which is now threatening a new leap to monster status.

For a powerful Kelvin Wave is presently lending heat to equatorial surface waters after receiving a boost from gale force westerly winds associated with the strongest Madden Julian Oscillation on record this past March. An raging equatorial heat engine that is now drawing yet more energy from a second set of strong westerlies developing this week.

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(Strong westerlies emerging in the Western Pacific on May 6 may provide yet another boost to the 2014-2015 El Nino. Image source: Earth Nullschool.)

In the above GFS summary, we find sustained winds in the range of 30 mph with gale force gusts in a region along and just north of the Equator near New Guinea. The winds are in association with a developing cyclone, one that models indicate will reach strong Typhoon status later this week. The westerlies stretch westward along the back of New Guinea and on toward the Philippines. There, they receive a boost from another cyclone — Tropical Storm Noul.

The result is a brisk set of westerlies running against the trades along hundreds of miles of open ocean. The kind of event with the potential to further strengthen an El Nino that is already at respectable intensity.

This week’s CFSv2 NOAA forecast models continued to indicate an extreme strength El Nino by later this year. Weighted models are now showing seasonal anomalies in the Nino 3.4 zone peaking out at +2.3 C. Weighted monthly models are showing peaks in the range of +2.5 C above average for Nino 3.4. And unweighted models are showing peak averages that now exceed +3.1 C. This is a jump from last week’s CFSv2 forecast. Another set in a continued trend for higher intensity.

Monster El Nino forecast

(NOAA’s forecast models show potential for extreme El Nino starting in June and extending into January. Image source: NOAA.)

Should such an event emerge it would truly be a monster. Something far worse than even the Super El Nino of 1998.

An extraordinary El Nino of this kind would have far-reaching climate and weather related impacts. It would push global temperatures into ever more dangerous ranges. It would strain global carbon sinks. And it would worsen drought and/or set off heavy precipitation events in various, already vulnerable regions of the globe. With model forecasts continuing to hit higher values, with so much available heat to fuel El Nino ranging the Pacific, and with strong westerlies continuing to reinforce the current El Nino, this is a situation that bears very serious continued monitoring.

Links:

Monster El Nino Emerging From the Depths

NOAA’s Climate Prediction Center

Earth Nullschool

March Shows Strongest Madden Julian Oscillation on Record

Starving Sea Lion Pups and Liquified Starfish

 

 

 

 

2015 El Nino to Bring Back-to-Back Hottest Years on Record?

For the past six months, the Pacific Ocean has been very, very warm. A vast and unsettling expanse of record heat building from the tropics on through the mid lattitudes and into the Arctic.

Sea surface temperatures across a broad swath of ocean from the equator on north and eastward have consistently measured between 0.5 and 5 degrees Celsius above average. A lazy reverse C pattern of heat stretching from the equator running up along the west coast of North America and then re-curving westward just south of the polar zone.

It is a pattern that is indicative of a well developed positive phase Pacific Decadal Oscillation. A kind of pattern that results in very warm sea surface temperatures for much of the Pacific. And a pattern that tends to favor the formation of El Nino.

As of December 2014, PDO values had climbed to their highest on record. And with these high sea surface temperature values related to PDO, the Pacific also seemed to be quietly settling into what, at first, appeared to be a mild El Nino.

Chances For 2015 El Nino Rise

The key value for El Nino is a measurement for sea surface temperatures along a region of the Central Equatorial Pacific known as Nino 3.4. Stretching from about 160 West to 120 West Longitude, this expansive zone of ocean waters below Hawaii tends to warm with the onset of El Nino.

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(Nino 3.4 zone in center of frame on the Earth Nullschool Sea Surface Temperature anomaly map for March 4, 2015 shows warm waters again building in the Central Pacific. Averages in the zone for this date are around +0.75 C above normal. Note the + 2 C hot pool just to the western edge of the zone [orange-yellow coloration] and the +4 C hot pools [yellow coloration] off the US West Coast. Image source: Earth Nullschool. Data Source: Global Forecast Systems Model.)

The threshold NOAA uses to determine El Nino is a sea surface temperature anomaly for this area of +0.5 degrees C above average. And ever since September of 2014, sea surface temperatures have been hovering above the +0.5 C line.

NOAA’s determination for El Nino requires 5 three month average periods in which Nino 3.4 exceeds this mark. And it looks like, so far, four out of five of those periods have met the El Nino requirement. September, October and November (SON) averaged +0.5 C. October, November and December (OND) averaged +0.7 C. And November, December and January (NDJ) averaged +0.7 C. With all weekly measures for February coming in near or above January values, it appears the DJF value will post somewhere near +0.6 C (please see NOAA’s Weekly ENSO Status Report).

Even if March values dropped to +0.4 C, a weak El Nino would emerge in the Pacific during Spring of 2015. However, sea surface temperatures for this zone are not falling as we enter March. They are instead ramping higher.

New Warm Kelvin Wave Forming

For beneath the Central Pacific a new pool of warm water is forming. It is rising to the surface, providing yet another shot of heat to an equatorial region teetering on the threshold of El Nino. A new Kelvin Wave that carries with it more than enough energy to tip the scales for a 2015 event:

El Nino Kelvin Wave

(Warm Kelvin Wave again forming in the Pacific. This event will likely be enough to push 2015 into El Nino. Image source: NOAA/CPC.)

The Kelvin Wave will slowly rise to the surface, elongate and transfer some of its latent heat to the sea surface and atmosphere. Driving this Kelvin Wave along are west wind backbursts that today were in the range of 25 mph sustained with gusts to 35. These gusts are continuing to drive warm water eastward and downward, providing more energy for the Kelvin Wave as well as any emerging El Nino. A set of winds that could well grow stronger as a weather pattern know as the Madden Julian Oscillation (MJO) is predicted to ramp up, bringing stormy weather and more counter trade wind air flows across the Western Pacific equatorial zone.

These combined factors have spurred Australia’s Bureau of Meteorology to post a renewed El Nino Watch. NOAA is also showing a heightened chance for El Nino, with a near 60% probability for the event emerging late winter or early spring.

Meanwhile, some models for the Nino 3.4 region show continued warming along with a heightening El Nino throughout 2015:

2015 El Nino

(BoM Nino 3.4 sea surface temperature anomaly (SSTA) prediction model shows El Nino building throughout 2015. Note that the Australia BoM SSTA threshold is +0.8 C for Nino 3.4 while NOAA’s threshold is SSTA in excess of +0.5 C for seven months running. Image source: Bureau of Meterology.)

Back-to-Back Record Hot Years?

The +1.9 C peak and rising prediction for Nino 3.4 in the above graphic is indicative of a relatively strong El Nino by mid November of this year (for reference, the 1998 Super El Nino peaked at around +2.3 C for this region while 2010 peaked at +1.5 C). But even a far milder El Nino would likely have far-ranging consequences, especially in a world that has been pushed to keep warming and warming by the massive human fossil fuel emission.

All that heat again building along the equatorial Pacific would likely shove the Earth’s oceans and atmospheres again above record thresholds. And that would mean that 2014’s record as the hottest year for the Earth’s surface may only stand for but a few seasons more.

The risks for another record hot year for 2015 are, therefore, again rising.

UPDATE:

As of March 5, 2014, NOAA has now officially declared weak El Nino conditions for the Equatorial Pacific. Please see this related discussion LINK.

Links:

Bad Climate Outcomes

NOAA’s Weekly ENSO Status Report

NOAA/CPC

Australia’s Bureau of Meterology

Earth Nullschool

Global Forecast Systems Model

Madden Julian Oscillation (MJO)

Hat Tips:

Colorado Bob

Phil

Scientific Hat tip to Kevin Trenberth and Michael Mann

Wili

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