Typhoon Ragasa

Typhoon Ragasa, designated as the eighteenth named storm and eighth typhoon of the 2025 Pacific typhoon season, originated from a disorganized area of convection north of Yap. Its genesis on September 17 was initially hampered by moderate vertical wind shear, a factor that typically inhibits tropical cyclogenesis. However, as the system organized, it was upgraded to a tropical storm on September 18 and named Ragasa by the Japan Meteorological Agency (JMA).

The subsequent two days saw a steady intensification, culminating in its classification as a typhoon on September 19. This phase illustrates the critical balance between atmospheric conditions and the development of a nascent tropical cyclone, where favorable sea surface temperatures and reduced shear allow for sustained organization and energy acquisition.

Ragasa's most dramatic intensification occurred on the morning of September 22, a phenomenon known as rapid intensification. This surge propelled it to its peak intensity as a violent typhoon, characterized by a minimum central pressure of 905 hPa and ten-minute sustained winds reaching 205 km/h (125 mph). Concurrently, it was assessed as a Category 5-equivalent super typhoon on the Saffir-Simpson scale, with one-minute maximum sustained winds of 270 km/h (170 mph).

This extreme intensity was maintained even as Ragasa entered an eyewall replacement cycle, a complex internal process where a new, larger eyewall forms and contracts, often leading to a temporary weakening before re-intensification. The occurrence of such a powerful storm, especially one undergoing eyewall replacement while at peak intensity, underscores the dynamic and often unpredictable nature of tropical cyclones.

Ragasa's track was notable for its extensive reach and multiple landfalls. It first made landfall over Panuitan Island in Calayan, Cagayan, Philippines, bringing severe weather to Northern Luzon. The Babuyan Islands experienced the highest tropical cyclone warning signal, No. 5.

Subsequently, as Ragasa traversed the South China Sea, it passed near Hong Kong, prompting the Hong Kong Observatory to issue Hurricane Signal No. 10. This was the second instance of this highest signal being hoisted in Hong Kong in 2025, a rare occurrence highlighting the storm's intensity and proximity. The storm made its second landfall on Hailing Island in Yangjiang, Guangdong province, China, on September 24, and continued inland, crossing Guangxi province and then entering Vietnam as a weakening tropical storm before dissipating in the mountainous terrain of Northern Vietnam.

This trajectory demonstrates the storm's ability to maintain significant strength over a large oceanic basin and impact diverse geographical regions.

The destructive power of Typhoon Ragasa manifested in widespread flooding and landslides across the Philippines, Taiwan, and Hong Kong, leading to a tragic loss of life. At least 29 fatalities and 219 injuries were reported. A particularly devastating event occurred in Taiwan with the bursting of the Matai'an Creek Barrier Lake, which resulted in 18 deaths and 6 missing persons.

Meteorologically, Ragasa was recognized as the second most intense tropical cyclone globally in 2025 up to that point, surpassed only by Hurricane Melissa in the Atlantic. This comparative intensity underscores its significance within the broader context of global weather phenomena for that year, serving as a critical case study for understanding extreme tropical cyclone development and its far-reaching consequences.