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Storms of My Grandchildren Rising: Hurricane Amanda Sets Record as Strongest Eastern Pacific Ocean Cyclone in May

Category 5. Only the most powerful of the most powerful storms on Earth reach this ominous peak. It’s a designation that occurs when hurricanes achieve a highly destructive wind strength greater than 156 mph. Usually relegated to late season storms that form and strengthen when the ocean surface temperature is at its hottest, it is a very, very, very rare event to see any storm approach Cat 5 status at the start of hurricane season.

Water temperatures are typically not high enough to support such a monster event so early.

But this Sunday, just six months after the Western Pacific spawned Typhoon Haiyan, the most powerful storm ever to strike the land, the three-day-old hurricane Amanda raged to just shy of Cat 5 status in the Eastern Pacific. Peaking at a maximum sustained wind speed of 155 mph, the storm teetered at the edge of highest intensity category even as it roared its way into the record books as the mightiest storm ever recorded for this region of the world in May.

Hurricane Amanda May 25

(Hurricane Amanda at strong Category 4 status on May 25. Image source: LANCE-MODIS.)

By comparison, the storm Amanda beat out, Adolph, was also a rather recent event, forming on May 25 of 20o1 and reaching a peak intensity of 145 mph on May 29th.

Hot, Deep Water

Hurricane season in the Eastern Pacific starts on May 15. Amanda began to gather just four days after, as a tropical disturbance, on May 19th. The storm gradually gained strength as it drifted north and west into extraordinarily warm waters that ranged from 1 to 3.6 C above typical temperatures for this time of year. By Sunday, May 25, the storm had exploded to just shy of category five status.

Extreme heat intensity fueling Amanda came from a Pacific Ocean exploding with warmth. The equatorial Pacific was just tipping into the hot ocean surface event that is El Nino even as overall Pacific anomalies ranged near 0.8 C above the, already hotter than normal, 1979 to 2000 average. The net result was that Amanda was fueled by sea surface temperatures in the range of 27 to 30 degrees Celsuis with hurricane-supporting warmth pushing as far as 50 meters into the depths. As a result, cool ocean water upwelling through Ekman pumping had far less effect on this storm than is typical for early in the season when the sun’s rays usually have not pushed warmth so deep.

Ocean surface anomaly May 28

(Today’s ocean surface temperature anomaly at +1.13 C on May 28th. Global Ocean surface temperature anomalies have been in the record range of +1 C above 1979-2000 values all throughout May. Hot ocean surface temperatures of this kind is hyperfuel for hurricanes. It is no accident that the record storm that was Amanda formed in the visible hot pool off the west coast of Mexico. Image source: University of Maine.)

Hurricanes are nothing if not ocean heat and moisture engines. The storms feed on hot air rising off the ocean surface, and their cyclonic action churns the waters below them eventually limiting their intensity as the strongest storms dredge into cooler waters. But with human warming, both the ocean surface as well as the waters far below show ever increasing heat potentials. This heat is nothing if not high-efficiency energy for oceanic, warm core cyclones.

Global Warming Heat Engine — Lengthens Storm Season, Generates More Powerful Cyclones

Amanda’s anomalous intensity was, thus, no accident. Instead, it was directly related to the extreme ocean heating that is an attribute of human-caused warming. The danger here is not only for more intense storms and for more intense storms coming earlier and earlier in the year, it is also for a general lengthening of the period during which these powerful storms emerge. The risk, therefore, is that hurricane season will extend deeper into the Spring and further into Fall for both the Eastern Pacific and the Atlantic. And during this ever-growing storm year the higher heat values increase the likelihood of monster storms reaching and exceeding category five strength.

The currently explosive Western Pacific may well foreshadow events for other regions of the world. That volatile storm zone already sees some seasons featuring year-round hurricanes and tropical storms. And the already intense cycle there is also likely to strengthen as the oceans continue to warm.

Links:

Dr. Jeff Masters: Amanda Peaks as Strongest May Pacific Cyclone on Record

LANCE-MODIS

Abnormally Hot Pacific Ocean Explodes Haiyan into 195 mph Monster

University of Maine

 

 

 

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Monster El Nino Emerging From the Depths. Nose of Massive Kelvin Wave Breaks Surface in Eastern Pacific

Monster El Nino

(A monster Kelvin wave, possibly more powerful than the 1997-98 event, is now rushing toward the surface of the Eastern Pacific. Image source: NOAA/ESRL.)

We are observing an extraordinarily powerful Kelvin Wave, one that was likely intensified by factors related to human global warming, traveling across the Pacific. It appears to be an epic event in the making. One that may be hotter and stronger than even the record-shattering 1997-98 El Nino. What this means is that we may well be staring down the throat of a global warming riled monster.

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Ever since the early 2000s very strong east to west trade winds have been blowing across the Pacific. By around 2010, the force of this wind pattern had risen to never before seen records. Over the years, these record winds piled very warm waters in a region of the world east of the Philippines and Australia. As the pool grew warmer, evaporation increased and salinity levels in the hot water pool spiked. Increasing salinity in the zone resulted in a down-welling current that transferred heat into the ocean’s depths.

By 2013, this hot water pool had grown into a vast abyss of heat. Cyclones forming over this zone experienced a kick in intensity as the typical upwelling force of their winds only dredged more hot water from the ocean deeps. It was a pattern that is contrary to typical tropical storm dynamics in which cooler waters drawn up by intense storms tend to limit their peak strength. Not so with mega-typhoon Haiyan, the strongest storm ever to strike land. The cyclonic wind pattern only dredged more heat from the extraordinarily deep hot water. And so the storm only grew stronger and stronger, knowing little in the way of limits before it barreled into an already storm-battered Philippines.

After Haiyan’s passage, the heat pool remained, only growing deeper and more intense, waiting for a change in the wind. And by January of 2014, that wind change was already well on its way.

In Deep, Hot Water

Like an enormous bag waiting to burst eastward, the hot water pool contained temperatures of 29-30 degrees C or hotter and sagged deep, extending up to 150 meters below the ocean surface. A vast stretch of explosive heat that had been held in check from an equatorial surge only by the strongest trade winds on record. But by January, those trade winds had faded. The east-west flow first weakened, then it fluttered, then it died, allowing the wind direction to reverse.

Strong Trade Winds Hot Ocean

(Did strong trade winds intensify the current Kelvin Wave by piling hot water into the Western Pacific? Top graph shows ocean heat content rise, bottom graph shows zonal wind strength of the trade winds through 2011. Note that IPO — Interdecadal Pacific Oscillation — divergence roughly correlates with trade wind intensity fluctuation. Image source: England Study.)

This trade wind reversal has, since January, been facilitated by a string of explosive low pressure systems that developed in the vicinity of the Western Pacific both south and north of the equator. Northern hemisphere storms circulate in a counter-clockwise fashion while southern hemisphere storms circulate clockwise. When the storms line up, they kick storm winds out along the equator, providing strong reversals to the trade winds and further shoving our hot, monster Kelvin Wave to the east.

And as the trade winds fell and reversed due to this sporadic assault of countervailing storms, the hot, deep pool of water surged eastwards. To those on the surface, the motion was invisible. And but for a series of floats spread throughout the Pacific, we would never know a monster thing was rushing along toward the east at a depth of about 150 meters below.

But the floats did their work and by late February it looked like a rather strong heat pulse was on its way across the Pacific Ocean. Risks began to dramatically increase that the heat would breach the surface of the Eastern Equatorial Pacific and set in place the globe-altering weather pattern called El Nino. In a world where human warming was already having serious impacts, the emergence of a new, potentially strong El Nino was not at all a welcome sign. For one, it meant new global high temperature records were likely to soon follow.

It also meant that world food security may well be about to receive yet one more staggering blow.

First Warnings

As the signal for a new El Nino began to appear in the models during late February, NOAA started to issue watches and predictions. Initial estimates were for a 52% chance of El Nino by late 2014.

These warnings caused a ripple of concern through the global food markets. Already reeling under the insults of a series of severe, climate change induced, droughts from Brazil and Argentina, to California and Texas, to the Middle East, to China, the world’s growers were hardly prepared for another series of anomalous weather events. Russia rolling into bread-basket Ukraine further set anxieties alight. But the threat of even a moderate El Nino and its associated droughts and extreme weather seemed to be a rising perfect storm for what was already a terrible year.

Growers in Southeast Asia chided forecasters in the West, with some cautioning that El Nino trackers do their best to quiet down so as not to induce a panic.

Southeast Asia often experiences an interruption of the annual monsoon in association with El Nino. So the region, which was already suffering from ground water shortages, lowering glacial outflows and sporadic periods of intense drought — all conditions related to growth, over-consumption and climate change — could ill afford yet one more strike against it.

Still, the strike appeared to be gathering heat and steam.

A Rising Monster Pushing the Tip of Its Nose up in the Eastern Pacific

As growers and states with marginal or bad food security grew more anxious, the hot water surge intensified. Researchers independent of NOAA began to issue estimates for a 60, 70 even 80% probability for the emergence of El Nino. Others, tracking what now appeared to be the hottest Kelvin wave ever seen, began to issue warnings that a monster event may well be on the way.

Deep Hot Water

(Most recent NOAA Kelvin Wave assessment. Top panel shows deep water high temperature anomalies telegraphing across the Pacific and pushing toward the surface. Large, deep pool of hot water providing energy to for the wave is visible in the bottom panel. Image source: NOAA.)

At issue were deep ocean temperature anomalies that were now rushing across the Pacific and beginning to rise toward the surface. The zone in late February that had indicated temperature anomalies in the range of +4-6 C was over an area of approximately 48 degrees of longitude. By March 19, the hot zone of 4-6 C above normal temperatures had expanded to cover about 62 degrees of longitude, and contained a hotter 5-6 C anomaly zone that was now larger than the 4-6 C zone from late February. The deep, hot water pool in the Western Pacific was now beginning to set up a kind of bridge in which it could transfer east, dump its heat into the atmosphere and disrupt global weather. Perhaps, somewhat more disturbing, it was linking to a deep pool of warmer water off the coast of South America (also see animation at the top of this post).

By comparison, the monster El Nino of 1997 featured a Kelvin Wave covering about the same area but whose high temperature anomalies only peaked out at about 4.5 C above average. So the current Kelvin wave is of approximately the same size but, based on current observations, appears to contain more heat.

The Kelvin wave had also begun to tilt up in the front with its ‘nose’ just starting to break the Pacific Ocean surface at between 120 and 100 West Longitude. This put the tip of the rising heat spike almost due south of Baja California and almost due west of the Peru and Ecuador border as of yesterday, March 23.

Monster El Nino Shows Nose

(Monster El Nino pokes the tip of its nose through Pacific surface waters between 120 W longitude and 100 W longitude along the equator. Image source: NOAA/ESRL.)

In the above ocean temperature anomaly measure for March 23, 2014, we can see a hot pool in the range of 1 to 2 C above average beginning to emerge between 120 and 100 West Longitude. It is a heat pulse that has eliminated all but the closest near-shore cool upwelling along the west coast of South America.

Should the rest of the Kelvin wave follow, spot temperature anomalies in this region will spike well above 4 C and possibly has high as 5-6 C. Such an event would be even stronger than the one seen in 1997-98, drive global temperatures about .05 to .2 C hotter than previous records in a single year, and set off a series of extreme weather that, when combined with the already severe conditions set in place by human-caused warming, may well be far in excess of those seen during past events.

Links:

NOAA/ESRL

England Study

Abnormally Hot, Deep Pacific Ocean Waters Explode Haiyan into Monster Storm

NOAA El Nino Monitoring

Climate Change Pushing World to the Brink of Food Crisis

The Monsters of Growth Shock Rise: Conflict in the Ukraine, Global Food Crisis, and Spending 500 Billion Dollars to Wreck the Climate

India Times Chides Western Meteorologists about El Nino Predictions

Unusually Intense El Nino May Lie Ahead, Scientists Say

Disquieting Facts About El Nino

Washington Post: A Super El Nino May be on the Way

US Atmospheric Scientists Predict Intense El Nino

Weather Centre: Could the Next Super El Nino Be Forming?

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