As September 2025 draws to a close, meteorological agencies across East Asia are issuing urgent updates about a rare and potentially hazardous weather event: the near-simultaneous development of three tropical cyclones in the northwest Pacific. According to reports from the Korea Meteorological Administration (KMA), Japan Meteorological Agency, and multiple regional news outlets, three tropical depressions—soon to be named typhoons Mitag, Ragasa, and Neoguri—are gathering strength and charting courses that could affect millions from the Philippines to South Korea, Hong Kong, and Japan.
The story began in mid-September, when meteorologists first detected three distinct tropical disturbances swirling in the northwest Pacific’s warm waters. By September 18, at 3 AM, the 37th tropical depression of the year was located about 500 kilometers north-northwest of Manila, the Philippines, with a central pressure of 1004 hPa and maximum sustained winds of 15 meters per second (54 km/h), as detailed by Aju News. This system was forecast to intensify, and by September 19, it was expected to reach typhoon status and receive the name Mitag, a moniker submitted by the Federated States of Micronesia and traditionally used as a female name.
Meanwhile, another system was brewing further east. The 38th tropical depression, observed at 3 AM on September 18 about 820 kilometers north of Palau, was also packing winds of 15 meters per second and a central pressure of 1004 hPa. Meteorologists predicted this system would strengthen into Typhoon Ragasa by September 19, with forecasts showing it moving toward the northeast of Manila and possibly intensifying as it approached Taiwan and the Korean Peninsula. The name Ragasa, submitted by the Philippines, is a variation of the Tagalog word “Dagasa,” which means “fast movement” or “violent storm,” a fitting descriptor for the turbulent season.
Adding to the region’s weather woes, a third system—dubbed the 39th tropical depression—was identified by the Japan Meteorological Agency at 5:30 AM on September 18, roughly 2,000 kilometers northeast of Guam. This system, originally tracked as a tropical disturbance labeled 91W, was expected to strengthen and move westward, potentially making landfall in the Japanese mainland and earning the name Neoguri, after a mammal native to East Asia and Russia’s Far East, as reported by Imaeil.
As these tropical systems evolved, meteorological agencies issued a flurry of updates. The KMA projected that by September 20, at 3 AM, Mitag would be approaching the northern coast of Hong Kong with wind speeds near 70 km/h. By September 21, at 3 AM, the system was expected to weaken as it moved inland, passing about 190 kilometers northwest of Hong Kong. Concurrently, Ragasa was forecast to be northeast of Manila, with gradual intensification likely, according to Aju News and Imaeil. Forecasters were especially concerned about Ragasa’s potential to strengthen further as it moved over warm waters between the Philippines and Taiwan, possibly reaching a Category 3 status with a central pressure dropping to 970 hPa by September 23.
Despite the proliferation of named storms this year—by mid-September, sixteen typhoons had already formed in the northwest Pacific—South Korea had thus far escaped direct impact. That could soon change. Meteorologists warned that between September 20 and 23, the Korean Peninsula, especially its eastern regions, could feel the effects of these typhoons, either from direct landfall or heavy rains and winds associated with their outer bands. The Japanese Meteorological Agency and KMA both highlighted the unusual nature of three tropical cyclones developing in such close succession, a phenomenon that complicates forecast models and heightens the risk of overlapping impacts.
“We are closely monitoring the development and projected paths of Mitag, Ragasa, and Neoguri,” said a KMA spokesperson in a statement published by Aju News. “The interaction between these systems could result in unexpected changes in intensity or trajectory, so residents in affected regions should remain vigilant and heed official advisories.”
Forecast maps released by the meteorological agencies showed the 37th depression (soon to be Mitag) moving northwest across the South China Sea, skirting the northern coast of Hong Kong before weakening inland. The 38th depression (Ragasa) was charted to move northwest between Luzon and Taiwan, with a strengthening trend as it approached the East China Sea. Meanwhile, the 39th depression (Neoguri) was on a westerly course toward Japan, raising concerns for the Japanese mainland later in the week.
Complicating matters further, meteorologists noted the presence of several additional tropical disturbances in the region, particularly in the waters off Okinawa and the broader northwest Pacific. This abundance of so-called “typhoon seeds” could lead to the formation of even more storms—specifically, the 19th and 20th typhoons of the season, which would be named Neoguri and Bualoi, respectively. However, as of September 18, the intensity and precise tracks of these potential storms remained uncertain.
For the time being, the focus remains squarely on Mitag, Ragasa, and Neoguri. According to Imaeil, the order in which these depressions are officially named depends on which system first meets the criteria for typhoon status—namely, sustained winds of at least 17 meters per second. While the numbering of the depressions is sequential, the assignment of names may shift based on the pace of intensification, adding another layer of complexity for forecasters and the public alike.
Historical context underscores the seriousness of the situation. The northwest Pacific is the world’s most active typhoon basin, and September is typically its peak season. Yet, the near-simultaneous emergence of three potentially significant storms is rare, raising concerns about cumulative impacts, especially in densely populated coastal cities such as Hong Kong, Manila, Taipei, Seoul, and Tokyo. The possibility of one storm altering the atmospheric environment for another—through a phenomenon known as the Fujiwhara effect—means that even the best forecasts are subject to rapid revision.
As of September 18, none of the typhoons had yet made landfall, but authorities across the region were already preparing for the worst. Emergency management agencies in South Korea, Hong Kong, the Philippines, and Japan urged residents to secure property, review evacuation plans, and monitor official updates as the storms approached. “We urge all citizens to stay informed and take necessary precautions,” the KMA emphasized in its advisories.
Looking ahead, meteorologists will be watching closely as Mitag, Ragasa, and Neoguri continue their march across the Pacific. With the potential for high winds, torrential rains, and dangerous storm surges, the coming days could test the resilience of communities across East Asia. For now, all eyes are on the sky—and the latest updates from the region’s weather experts.