Typhoons, heat waves, torrential rains: Has the 'climate domino' already begun?

A massive marine heat wave spanning the Pacific Ocean could trigger a chain of weather disruptions around the world over the coming weeks and months, forecasters warn.

According to The Washington Post on Sunday (local time), the marine heat wave now covers roughly 13.5 percent of Earth's surface, stretching from the Philippines to Peru and extending northward to Hawaii and the California coast — making it an event of extraordinary scale.

A marine heat wave is defined as a prolonged period — lasting anywhere from several days to several months — during which ocean temperatures remain abnormally higher than seasonal averages.

The current phenomenon is believed to have formed when a marine heat wave that developed in the North Pacific merged with a separate one that intensified near the equator under the influence of a super El Niño.

Unusual conditions are already emerging. In Peru, which is in the Southern Hemisphere and currently in winter, temperatures have been warmer than normal, drawing unusually large crowds to beaches.

Dylan Amaya, a climate scientist who has studied ocean warming off California, said "months of warming could mean pronounced impacts this winter and into next spring."

The Post identified two weather phenomena to watch within the next two weeks in connection with the marine heat wave.

The first is Typhoon Bavi, the ninth named storm of the season, which is intensifying in the western Pacific.

As of Monday morning (local time), Bavi was maintaining very strong intensity as it tracked northwest near the Northern Mariana Islands, north of the US territory of Guam. Forecasters raised the possibility that it could significantly affect Taiwan and parts of China this weekend.

The second variable is a powerful heat dome expected to form over the western United States.

A heat dome occurs when a strong high-pressure system traps hot air in a dome-like formation, dramatically raising surface temperatures below.

Eric Webb, a meteorologist with the US Department of Defense, warned on social media platform X that the risk of extreme heat and wildfires could intensify across the western United States — not only in New Mexico and Arizona, which have already suffered severe wildfire damage, but throughout the broader region.

Experts are also paying close attention to the possibility that the effects of this marine heat wave could extend into autumn and winter.

The warming Pacific waters, combined with seasonal storms, are expected to raise the risk of sea-level rise along the California coast.

Climate scientist Daniel Swain said in a recent live stream that the likelihood of historically rare levels of heavy rain and storms this winter has increased.

He said the unusually warm Pacific waters could raise sea levels near California by 6 inches to 2 feet (about 15 to 61 centimeters). When the added effect of autumn and winter storm winds is factored in, coastal sea levels along California could rise by 2 to 3 feet or more — roughly 0.6 to 0.9 meters or higher.

In addition, as heat stored in the Pacific is released into the atmosphere, a strengthening subtropical jet stream could increase the likelihood of heavy rain and thunderstorms not only in California but also across the southern and eastern United States.

As ocean temperatures rise, evaporation increases, adding more water vapor to the atmosphere. That accumulated moisture can travel thousands of kilometers on atmospheric currents and trigger concentrated downpours in distant regions.

Europe is not immune. A marine heat wave formed in the Mediterranean following a heat dome-driven heat wave in June, and the abnormally high sea temperatures could intensify a heat wave expected to persist through mid-July.

More than 37 percent of the world's oceans are currently affected by marine heat waves.

In January 2024, when a strong El Niño was underway, more than 46 percent of the world's oceans were simultaneously experiencing marine heat waves — the highest level ever recorded.

The share of the global ocean surface affected by marine heat waves stood at around 9 percent in the late 1980s but has recently exceeded 30 percent, more than tripling over roughly four decades.

Climate experts say marine heat waves are not simply a matter of warmer seawater — they act as the starting point of a climate domino effect, linking typhoons, heat waves, torrential rains and wildfire risk in a chain reaction. Once the enormous heat stored in the ocean transfers to the atmosphere, the conditions for a cascade of disasters — typhoons, extreme heat, heavy rain and wildfires — grow significantly more likely.