(Bloomberg) --A strengthening El Niño is stirring up a dangerous mix of typhoons and hurricanes across the Pacific, fueling storms that have killed hundreds, disrupted trade and caused billions of dollars in damage.
Across the western Pacific, that burst of activity has brought a destructive mix of flooding, deaths and economic damage. Another storm neared Japan on Monday and more could be possible in the region through November.
The situation stands in contrast to a very quiet Atlantic, which has had its calmest start since 1941. Pacific cyclones have caused more than 230 deaths since April, media reports show, while natural disasters — including three back-to-back storms — caused an estimated $8.5 billion in direct economic losses in China in July alone,
"Beyond the number of storms, what is striking is the scale of flooding, displacement, and economic disruption already seen in places including southern China, the Philippines, and the Mariana Islands," said Graeme Riddell, who leads climate and sustainability consulting for Asia Pacific at Marsh.
The disruption hasn't been confined to communities in the storms' paths. Container shipping giant Maersk issued an advisory this month saying a string of severe typhoons had
Driving the activity are two overlapping sources of ocean heat. El Niño, which occurs when the equatorial Pacific warms and the atmosphere above it reacts, has been strengthening since it emerged in June and is creating conditions that favor tropical cyclones across much of the Pacific.
Beyond the waters directly affected by El Niño, an ocean heat wave linked to climate change has spread across parts of the eastern Pacific, said Jennifer Francis, a senior scientist at the Woodwell Climate Research Center.
"The warm blob off the coast of Mexico is providing rocket fuel for tropical disturbances forming there, and El Niño is helping by reducing the vertical wind shear that rips storms apart," Francis said. "About 90% of the heat trapped by extra greenhouse gases — produced mainly by burning fossil fuels and destroying forests — goes into heating the ocean."
The result has been an unusually crowded ocean. Twelve tropical cyclones
"Further activity is expected throughout the rest of September and through October, and perhaps into November, as El Niño strengthens and reaches its forecast peak values," said James Cosgrove, Associate Director Manager, Insurance Solutions at Moody's.
The central and eastern Pacific have been busy, too. At least 17 systems have reached tropical storm strength, with six becoming hurricanes and four reaching major status with winds of 111 miles (179 kilometers) per hour or more.
Hawaii has had five close calls. Hurricane Lowell triggered storm warnings on Oahu and Kauai earlier this month and spawned Hawaii's first tornado watch, while Hurricane Lala came within miles of striking the Big Island in August.
Even California found itself battered by waves more familiar to the US East Coast. Tropical Storm Marie passed hundreds of miles offshore earlier this month but flooded parts of the coastline and raised the risk of dangerous rip currents for swimmers.
More potential systems are being watched as thunderstorms and showers begin to coalesce off the coast of Mexico. Tropical storm watches have been posted near Mexico's state of Guerrero as another Pacific storm spins up and threatens to become a major hurricane.
Tropical Storm Polo, with top winds of 80 kilometers (50 miles) per hour, was about 386 kilometers south of the port city of Manzanillo, Mexico, moving northeast at 8 kph, the US National Hurricane Center said in an advisory Monday. Tropical storm watches reach from Tecpan de Galeana to Punta San Telmo.
While the storm is quite compact and is forecast to remain out to sea, it will still grow quite strong and could bring flooding rains along Mexico's coast.
The perils won't necessarily end as the Northern Hemisphere cools and tropical cyclones fade away. El Niño is forecast to continue strengthening toward its peak later this year, when its influence can bring another round of weather extremes far beyond the Pacific.
