Super Typhoon Chanthu, about 280 miles east of Manila, joins an elite group of some of the most rapidly intensifying storms ever observed. The expectation is that they will become more common because of human-caused climate change.
The storm poses a threat to the northern part of Luzon, the main island of the Philippines, Taiwan and the coast of China as a somewhat weaker storm as it progresses toward the west and northwest around 10 to 15 mph.
Only five previous storms on record have catapulted from a depression to a Category 5-equivalent storm in 48 hours, tweeted Sam Lillo, a researcher at the National Oceanic and Atmospheric Administration: Elida (2002), Ernie (2017), Willa (2018), Hagibis (2019) and Goni (2020).
Brian McNoldy, a tropical weather expert at the University of Miami and Capital Weather Gang contributor, called Chanthu’s intensification “absolutely stunning” in a tweet:
In just 24 hours, Chanthu’s peak winds increased over 100 mph, tweeted Kim Wood, an atmospheric scientist at Mississippi State University. A storm meets the criteria for rapid intensification if it strengthens just 35 mph in such time.
Rapidly intensifying tropical weather systems are projected to proliferate in a warming world. The potential intensity of hurricanes and typhoons is closely tied to the amount of heat stored in the oceans, which has been increasing. When warm waters run deep amid other favorable environmental conditions, storms can take off.
(Typhoons and hurricanes, while called different things, are identical weather systems; both describe storms of tropical origin with peak winds of at least 74 mph. Super typhoons have peak winds of at least 150 mph.)
While Chanthu hastily strengthened in the western Pacific Ocean, many storms in the Atlantic have also seen such leaps as ocean temperatures have set record highs. During the hyperactive 2020 Atlantic hurricane season, 10 storms rapidly intensified.
Rapid intensification is particularly dangerous if it occurs leading up to a storm’s landfall. This occurred with Hurricane Ida, which jumped from a Category 1 to Category 4 before it slammed into Southeast Louisiana.
Chanthu is projected to see fluctuations in intensity along its path, but ultimately weaken.
Since peaking as a Category 5-equivalent storm early Wednesday, Chanthu has seen its peak winds ease to around 150 mph, making it the equivalent of a high-end Category 4 hurricane.
Chanthu’s rather small size — it has a pinhole eye just six miles across — makes it subject to frequent changes in strength. It may make another run at Category 5 strength Friday as it transits warm water east of Luzon.
Modest weakening is forecast as it pulls north of Luzon on Satuday; along the way it could graze northern areas of the island with gusty showers.
The latest track projection brings Chanthu over Taiwan Saturday into Sunday, where serious impacts from damaging winds, heavy rain and coastal flooding are possible. The interaction with land would weaken the storm before emerging in the East China Sea and paralleling China’s east coast Sunday and Monday. Then cooling water and hostile high altitude winds would probably weaken Chanthu into a tropical storm south of South Korea early next week.
Chanthu has flourished in a mostly quiet year for storms in the western Pacific Ocean. Jeff Masters, meteorologist and blogger for Yale Climate Connections, noted that last month marked the first August in which a typhoon failed to develop in the region. “Chanthu gives the basin five typhoons to date, compared to the average of nine,” he wrote.
Yet one of the 2021’s other typhoons, Surigae, which formed in April, also made headlines for its rapid increase in strength. Its winds increased 105 mph in 36 hours, which was unprecedented for an April storm.