Rare train of Pacific cyclones fueled by historic El Nino

Two powerful hurricanes and a strengthening tropical storm on Wednesday were churning through the Pacific Ocean where waters were being warmed by a historically strong El Nino climate episode. 

Furthest west is Hurricane Lowell, followed by Hurricane Karina. Both of the Category 4 storms are anticipated to pass well to the south and to the northeast of Hawaii, respectively, according to the National Hurricane Center (NHC).

However, uncertainty remains over their tracks, with the possibility Lowell could pass close to the archipelago's westernmost islands.

Hawaii is still recovering from the impacts of Hurricane Lala, which brushed past the southern part of the Big Island last month, bringing destructive winds and severe flash floods.

Lowell and Karina are trailed to the east by Tropical Storm Marie, currently a few hundred miles south of Baja California and "expected to become a hurricane later today," the NHC said.

"El Nino warming sets the stage for these storms, which are fuelled in large part by warm waters -- when the tropical Pacific is warmer than normal we see an increase in strong storms," Julia Cole, a climate scientist at the University of Michigan, told AFP.

A train of three cyclones "is definitely rare to see," she added.

A similar train of four cyclones happened in 2015, another intense El Nino year, when Typhoon Kilo, Hurricane Ignacio, Hurricane Jimena and Tropical Depression 14E crossed the Pacific at once.

"The climate system has significantly warmed over the last 20 years or so," said Benjamin Kirtman, an atmospheric scientist at the University of Miami.

Warm waters provide fuel for storms, and El Nino's effect on the atmosphere leaves little vertical wind shear over the Pacific, creating favorable conditions for hurricanes to intensify.

"There's no other way to put it -- it is juicy out there right now," he told AFP.

What's more, the sea surface temperature anomaly -- how much warmer the ocean is compared to average -- is already near record high, right in the middle of the Pacific hurricane season, Kirtman explained.

This year's El Nino has a 69 percent chance of becoming the strongest on record, according to the National Oceanic and Atmospheric Administration, and is already unleashing extreme weather across the globe even though it is not expected to peak until October-December.

Peru, the world's largest catcher of anchovy, is facing a devastating blow from warming seas that have gutted production, according to industry officials. In Sudan, El Nino is blamed for delaying crucial rains that have led water levels in the Nile to drop precipitously.

El Nino is the warming phase of a natural cycle in the tropical Pacific known as the El Nino-Southern Oscillation (ENSO), and comes along every two to seven years.

It sets in when east-to-west trade winds ease, allowing warm water which normally piles up in the western Pacific Ocean to slide back east and rise to the surface.

When those warmer-than-average surface temperatures last for a few months, they cause more storms and clouds over the region, which in turn cause ripple effects through the entire global atmosphere: hotter and drier conditions in some places, cooler and wetter in others.

Climate change increases El Nino's impacts. A warmer atmosphere holds more moisture, so El Nino-linked rains can turn more extreme. It also dries out soils, deepening drought where El Nino brings drought.