Tropical Storm Pulasan, known in the Philippines as Tropical Storm Helen, was a

tropical cyclone A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its locat ...

that impacted the

Mariana Islands The Mariana Islands ( ; ), also simply the Marianas, are a crescent-shaped archipelago comprising the summits of fifteen longitudinally oriented, mostly dormant volcanic mountains in the northwestern Pacific Ocean, between the 12th and 21st pa ...

East China East China () is a geographical region in the People’s Republic of China, mainly consisting of seven province-level administrative divisions, namely the provinces (from north to south) Shandong, Jiangsu, Anhui, Zhejiang, Jiangxi, Fujian, ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...

and the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

in mid-September 2024. Pulasan developed over the

Philippine Sea The Philippine Sea is a List of seas#Marginal seas by ocean, marginal sea of the Pacific Ocean, Western Pacific Ocean east of the list of islands of the Philippines, Philippine Archipelago (hence the name) and the List of seas#Largest seas ...

as a tropical depression on September 15 and strengthened into the fourteenth

named storm Tropical cyclones and subtropical cyclones are named by various warning centers to simplify communication between forecasters and the general public regarding forecasts, watches and warnings. The names are intended to reduce confusion in the ...

of the annual typhoon season the following day. After gaining organization, the system rapidly developed and reached its peak intensity with winds of 85 km/h (50 mph) and a central pressure of . Pulasan then turned northwestward, eventually moving across

Okinawa Island , officially , is the largest of the Okinawa Islands and the Ryukyu Islands, Ryukyu (''Nansei'') Islands of Japan in the Kyushu region. It is the smallest and least populated of the five Japanese archipelago, main islands of Japan. The island is ...

and making

landfall Landfall is the event of a storm moving over land after being over water. More broadly, and in relation to human travel, it refers to 'the first land that is reached or seen at the end of a journey across the sea or through the air, or the fact ...

Zhoushan Zhoushan is an urbanized archipelago with the administrative status of a prefecture-level city in the eastern Chinese province of Zhejiang. It consists of an archipelago of islands at the southern mouth of Hangzhou Bay off the mainland c ...

Zhejiang ) , translit_lang1_type2 = , translit_lang1_info2 = ( Hangzhounese) ( Ningbonese) (Wenzhounese) , image_skyline = 玉甑峰全貌 - panoramio.jpg , image_caption = View of the Yandang Mountains , image_map = Zhejiang i ...

, followed by a second landfall in

Shanghai Shanghai, Shanghainese: , Standard Chinese pronunciation: is a direct-administered municipality and the most populous urban area in China. The city is located on the Chinese shoreline on the southern estuary of the Yangtze River, with the ...

, just days after Typhoon Bebinca affected the Shanghai area on September 19. Pulasan reemerged over the

East China Sea The East China Sea is a marginal sea of the Western Pacific Ocean, located directly offshore from East China. China names the body of water along its eastern coast as "East Sea" (, ) due to direction, the name of "East China Sea" is otherwise ...

, just off the coast of China. By September 21, Pulasan had transitioned into an extratropical low as it moved east-northeastward and became embedded within the polar front jet to the north, passing over southern South Korea. The extratropical storm entered the

Sea of Japan The Sea of Japan is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, it ...

on September 22, crossed the

Tōhoku region The , Northeast region, , or consists of the northeastern portion of Honshu, the largest island of Japan. This traditional region consists of six prefectures (): Akita, Aomori, Fukushima, Iwate, Miyagi, and Yamagata. Tōhoku retains ...

, and then emerged into the Pacific Ocean while being absorbed by another extratropical cyclone. The extratropical remnants of Pulasan were last noted by the

Japan Meteorological Agency The Japan Meteorological Agency (JMA; ''気象庁, Kishō-chō'') is a division of the Ministry of Land, Infrastructure, Transport and Tourism dedicated to the Scientific, scientific observation and research of natural phenomena. Headquartered ...

on September 24 near the

International Dateline The International Date Line (IDL) is the line extending between the South Pole, South and North Poles that is the boundary between one calendar day and the next. It passes through the Pacific Ocean, roughly following the 180th meridian, 180.0� ...

; however, the

Ocean Prediction Center The Ocean Prediction Center (OPC), established in 1995, is one of the National Centers for Environmental Prediction's (NCEP's) original six service centers. Until 2003, the name of the organization was the Marine Prediction Center.Ocean Predictio ...

indicated that these remnants crossed the International Dateline and entered the Central North Pacific Ocean late on September 25. Afterward, the remnants gradually approached the coast of

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

, making landfall on September 27 and dissipating after moving inland the same day. As a monsoon depression, Pulasan produced winds and swells across the Mariana Islands. In China, more than of rainfall was recorded in Fengxian and

Pudong Pudong is a list of administrative divisions of Shanghai, district of Shanghai located east of the Huangpu River, Huangpu, the river which flows through central Shanghai. The name ''Pudong'' was originally applied to the Huangpu's east bank (g ...

Districts within a six-hour period, breaking historical records for each district since meteorological observations began.

Xinhua Xinhua News Agency (English pronunciation: ),J. C. Wells: Longman Pronunciation Dictionary, 3rd ed., for both British and American English or New China News Agency, is the official State media, state news agency of the China, People's Republic ...

reported that the city evacuated 112,000 people and suspended some ferry and train services. Heavy rains caused by Pulasan triggered widespread landslides and flooding in the Noto Peninsula, causing extensive damage that exacerbated the effects of the 2024 Noto earthquake, which devastated the region in January. In South Korea, the cities of

Changwon Changwon (; ) is the capital and largest city of South Gyeongsang Province, South Korea (with a population of 1,025,702 ), and the 11th largest city of the South Korea, country. A port city, Changwon is bordered by Masan Bay to the south, and the ...

Yeosu Yeosu, formerly romanized as Yosu, is a coastal city located on the southern shore of South Korea. With a population of 268,823, Yeosu is the second largest city in South Jeolla Province. In 1998, the Old Yeosu City, Yeocheon City and Yeocheon C ...

and

Busan Busan (), officially Busan Metropolitan City, is South Korea's second list of cities in South Korea by population, most populous city after Seoul, with a population of over 3.3 million as of 2024. Formerly romanized as Pusan, it is the economi ...

recorded , and of rainfall, respectively, on September 21. The remnants of Pulasan caused 15,000 customers to lose power, primarily on

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian province of British Columbia. The island is in length, in width at its widest point, and in total area, while are of land. The island is the largest ...

, especially in Campbell River and Courtenay. In total, the tropical storm caused at least 17 deaths, 50 injuries, and left 12 people missing.

Meteorological history

Tropical Storm Pulasan emerged from an area of

atmospheric convection Atmospheric convection is the vertical transport of heat and moisture in the atmosphere. It occurs when warmer, less dense air rises, while cooler, denser air sinks. This process is driven by parcel-environment instability, meaning that a "par ...

west-southwest of

Andersen Air Force Base Andersen Air Force Base (Andersen AFB, AAFB) is a United States Air Force base located primarily within the village of Yigo in the United States territory of Guam. The host unit at Andersen AFB is the 36th Wing (36 WG), assigned to the Pacif ...

Guam Guam ( ; ) is an island that is an Territories of the United States, organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. Guam's capital is Hagåtña, Guam, Hagåtña, and the most ...

on September 14.Alt URL
/ref> Satellite imagery indicated a broad, elongated area of circulation obscured by flaring and disorganized deep convection, with the disturbance situated in a favorable environment for development. At 00:00

UTC Coordinated Universal Time (UTC) is the primary time standard globally used to regulate clocks and time. It establishes a reference for the current time, forming the basis for civil time and time zones. UTC facilitates international communica ...

on September 15, the

(JMA) designated the system as a tropical depression. The United States

Joint Typhoon Warning Center The Joint Typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South P ...

(JTWC) issued a

tropical cyclone formation alert A Tropical Cyclone Formation Alert (TCFA) is a bulletin released by the U.S. Navy-operated Joint Typhoon Warning Center in Honolulu, Hawaii or the Fleet Weather Center in Norfolk, Virginia, warning of the possibility of a tropical cyclone formi ...

, noting that the system was disorganized, deep, fragmented, and had flaring convection obscuring the low-level circulation. Shortly after, the depression intensified into a tropical storm and was named ''Pulasan'' by the JMA. Pulasan was characterized by a large cyclonic circulation exceeding and extensive

gale-force The Beaufort scale ( ) is an empirical measure that relates wind speed to observed conditions at sea or on land. Its full name is the Beaufort wind force scale. It was devised in 1805 by Francis Beaufort a Hydrography, hydrographer in the Roy ...

winds, leading the JTWC to classify it as a monsoon depression at 06:00 UTC on September 16, before later upgrading it to a tropical storm and designating it as ''15W''. Pulasan progressed north-northeastward along the northwestern edge of a mid-level

subtropical high The horse latitudes are the latitudes about 30 degrees north and south of the Equator. They are characterized by sunny skies, calm winds, and very little precipitation. They are also known as subtropical ridges or highs. It is a high-pressure ...

, with a band of enhanced winds encircling the eastern edge, accompanied by deep convection, while the center stayed clear and was supplied with dry air from a

tropical upper tropospheric trough A tropical upper tropospheric trough (TUTT), also known as the mid-oceanic trough, is a trough situated in the upper-level (at about 200 hPa) tropics. Its formation is usually caused by the intrusion of energy and wind from the mid-latitudes into ...

cell to the west. By 11:00 PHT (03:00 UTC) on September 17, Pulasan had entered the

Philippine Area of Responsibility The Philippine Area of Responsibility (PAR) is an area in the Northwestern Pacific where PAGASA, the Philippines' national meteorological agency, monitors weather occurrences. Significant weather disturbances, specifically typhoons that enter o ...

(PAR) and was subsequently named ''Helen'' by the

Philippine Atmospheric, Geophysical and Astronomical Services Administration The Philippine Atmospheric, Geophysical and Astronomical Services Administration (, abbreviated as PAGASA , which means "hope" as in the Tagalog word ''pag-asa'') is the National Meteorological and Hydrological Services (NMHS) agency of the P ...

(PAGASA). The JMA reported that Pulasan reached its peak intensity at 00:00 UTC, with 10-minute sustained winds of and a central

pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and eve ...

of . By 12:00 UTC, the JTWC reported that the storm had peaked with 1-minute sustained winds of . Pulasan's low-level circulation has remained broad and somewhat exposed, as dry air continues to encircle its southern side while the system moves northwestward along the southwestern edge of a mid-level subtropical high. Pulasan exited the PAR on September 18 while traversing

in Japan's Ryukyu Archipelago as its circulation center strengthened with persistent convection, and satellite imagery displayed flaring convection along with weak easterly

outflow Outflow may refer to: *Capital outflow, the capital leaving a particular economy *Bipolar outflow, in astronomy, two continuous flows of gas from the poles of a star * Outflow (hydrology), the discharge of a lake or other reservoir system *Outflow ...

over the

. On September 19, Pulasan made

, followed by a second landfall in

, just days after Typhoon Bebinca affected the Shanghai area. As the storm moved overland, it maintained a well-defined circulation center; however, the system gradually turned northeastward under the influence of mid-latitude prevailing

westerlies The westerlies, anti-trades, or prevailing westerlies, are prevailing winds from the west toward the east in the middle latitudes between 30 and 60 degrees latitude. They originate from the high-pressure areas in the horse latitudes (about ...

. Pulasan reemerged over the East China Sea, just off the coast of

Jiangsu Jiangsu is a coastal Provinces of the People's Republic of China, province in East China. It is one of the leading provinces in finance, education, technology, and tourism, with its capital in Nanjing. Jiangsu is the List of Chinese administra ...

, China, showcasing a large, near-symmetric area of deep convection to the southeast on September 20. Meanwhile, satellite imagery and surface reports from

Jeju Island Jeju Island (Jeju language, Jeju/) is South Korea's largest island, covering an area of , which is 1.83% of the total area of the country. Alongside outlying islands, it is part of Jeju Province and makes up the majority of the province. The i ...

indicated that it was in the earliest phase of extratropical transition, with vigorous deep convection occurring over the southern semicircle. By 06:00 UTC on September 21, the JMA reported that Pulasan had transitioned into an extratropical low as it moved east-northeastward and became embedded within the polar front jet to the north, passing over southern South Korea. The JTWC then ceased issuing advisories on the system as it underwent

frontogenesis Frontogenesis is a meteorological process of tightening of horizontal temperature gradients to produce fronts. In the end, two types of fronts form: cold fronts and warm fronts. A cold front is a narrow line where temperature decreases rapidly. A ...

while entering the baroclinic zone. The extratropical storm entered the

on September 22, crossed the

, and then emerged into the Pacific Ocean while being absorbed by another extratropical cyclone. The extratropical remnants of Pulasan were last noted by the JMA on September 24 near the

; however, the

indicated that these remnants crossed the International Dateline and entered the Central North Pacific Ocean late on September 25. The remnants gradually approached the coast of

, making landfall on September 27, moving inland, and dissipating the same day.

Preparations and impact

Micronesia and Mariana Islands

As a monsoon depression, Pulasan produced westerly swells that affected Western

Micronesia Micronesia (, ) is a subregion of Oceania, consisting of approximately 2,000 small islands in the Northwestern Pacific Ocean. It has a close shared cultural history with three other island regions: Maritime Southeast Asia to the west, Poly ...

and the

. In

Saipan Saipan () is the largest island and capital of the Northern Mariana Islands, an unincorporated Territories of the United States, territory of the United States in the western Pacific Ocean. According to 2020 estimates by the United States Cens ...

, a wind gust of was recorded, higher than that of Typhoon Bebinca a week earlier. Maximum sustained winds of were observed at

Saipan International Airport Saipan International Airport , also known as Francisco C. Ada/Saipan International Airport, is a public airport located on Saipan Island in the United States Commonwealth of the Northern Mariana Islands. The airport is owned by Commonwealth P ...

, with a max gust of . A private weather station on Wireless Ridge reported winds of and a max gust of . Regardless, no damage was reported on the island. Flash flooding occurred in

when a monsoon surge produced a 24-hour total of . Sections of Route 1 in

Tamuning Tamuning, also known as Tamuning-Tumon-Harmon (), is a village located on the western shore of the United States territory of Guam. The village of Tamuning is the economic center of Guam, containing tourist center Tumon, Harmon Industrial Park, ...

and Route 4 in

Talofofo Talo'fo'fo, formerly Talofofo, is a village located in the southern part of the United States territory of Guam, on the east coast. The village center is located in the hills above the coast, while the smaller coastal community below the cliff is ...

were inundated and impassable, though other roads that were also flooded remained passable. Sustained winds of were observed, and a wind gust of was recorded at Andersen Air Force Base. Flights to and from the island were canceled or delayed. On September 17, three swimmers were swept away by large waves off of Gun Beach, before being rescued.

Asia

The Yangjiazhai meteorological station in

Fengxian District Fengxian District, is a suburban district in the south of Shanghai with a land area of , a registered population (as of 2020) of 1,140,872, and 1.5 to 2 times more migrants. It is known for its relative rusticity, as well as its beaches and oc ...

and the Nicheng Park meteorological station in

Pudong District Pudong is a district of Shanghai located east of the Huangpu, the river which flows through central Shanghai. The name ''Pudong'' was originally applied to the Huangpu's east bank, directly across from the west bank or Puxi, the historic city ...

both recorded more than of rainfall within a six-hour period, breaking historical records for each district since meteorological observations began. Due to Pulasan, winds of were recorded in

Fengxian, Shanghai Fengxian District, is a suburban district in the south of Shanghai with a land area of , a registered population (as of 2020) of 1,140,872, and 1.5 to 2 times more migrants. It is known for its relative rusticity, as well as its beaches and oc ...

, where several roads and neighborhoods were flooded.

reported that the city evacuated 112,000 people and suspended 26 ferry and 54 train services. Total damage in China was estimated at 30 million yuan (US$4.15 million). PAGASA reported that the

southwest monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscil ...

, enhanced by Soulik and Pulasan, will bring strong to

winds across the Philippines. 2024 CIMSS 15W Pulasan visible infrared satellite loop

As Pulasan approached Japan, 44,700 residents from Wajima, Suzu, and

Noto Noto (; ) is a city and in the Province of Syracuse, Sicily, Italy. It is southwest of the city of Syracuse at the foot of the Iblean Mountains. It lends its name to the surrounding area Val di Noto. In 2002 Noto and its church were decl ...

Ishikawa Prefecture is a Prefectures of Japan, prefecture of Japan located in the Chūbu region of Honshu island. Ishikawa Prefecture has a population of 1,096,721 (1 January 2025) and has a geographic area of 4,186 Square kilometre, km2 (1,616 sq mi). Ishikawa Pr ...

were given evacuation orders, along with 16,000 others in Yamagata and

Niigata Prefecture is a Prefectures of Japan, prefecture in the Chūbu region of Honshu of Japan. Niigata Prefecture has a population of 2,131,009 (1 July 2023) and is the List of Japanese prefectures by area, fifth-largest prefecture of Japan by geographic area ...

s. The

issued the highest level of alert for heavy rain across several cities in Ishikawa. Heavy rains caused by Pulasan triggered widespread landslides and flooding in the Noto Peninsula, causing extensive damage which exacerbated the effects of the 2024 Noto earthquake which devastated the region in January. The floods killed 16 people, injured 47, destroyed 673 houses and damaged 1,284 others. In Wajima, of rainfall was recorded within an hour. Up to ten people were left missing in the town, including four due to a landslide at a construction site. In Suzu, one person drowned and another was missing. In Noto, one person was missing and two others were critically injured after a landslide struck their home. At least twelve rivers across Ishikawa overflowed, and 6,500 households were left without power in the prefecture, according to the Hokuriku Electric Power Company. At least 903 people from 581 households were evacuated across six provinces in South Korea. The cities of

and

recorded , and of rainfall respectively on September 21. Flooding affected 83 sections of public roads—leading to 18 incidents of soil loss and a wall collapse—30 private facilities and 27 houses. Two trucks fell into a sinkhole in Busan. In

Yangju Yangju (; ) is a city in Gyeonggi Province, South Korea. Yangju is located south of Dongducheon and north of Uijeongbu, not far from Seoul. In the past, it was one region with Uijeongbu-si, Guri-si, Namyangju-si, Dongducheon-si, and some parts ...

city,

Gyeonggi Gyeonggi Province (, ) is the most populous province in South Korea. Seoul, the nation's largest city and capital, is in the heart of the area but has been separately administered as a provincial-level ''special city'' since 1946. Incheon, ...

province, an elderly man died after being swept away by a torrent. A total of 27 private homes were flooded, affecting almost 30 private businesses, including shops and factories. Moreover, 641 areas within 22 national parks throughout the country were still unreachable.

British Columbia

The remnants of Tropical Storm Pulasan have caused wind warnings for several areas in

, including the B.C. Coast, sections of

, the Central Coast, and

Haida Gwaii Haida Gwaii (; / , literally "Islands of the Haida people"), previously known as the Queen Charlotte Islands, is an archipelago located between off the British Columbia Coast, northern Pacific coast in the Canadian province of British Columbia ...

, while approximately 15,000 customers lost power, primarily on

, especially in Campbell River and Courtenay.

References

External links

15W.PULASAN
from the

United States Naval Research Laboratory The United States Naval Research Laboratory (NRL) is the corporate research laboratory for the United States Navy and the United States Marine Corps. Located in Washington, DC, it was founded in 1923 and conducts basic scientific research, appl ...

General Information
of Tropical Storm Pulasan (2414) from Digital Typhoon
JMA Best Track Data (Graphics)
of Tropical Storm Pulasan (2414)
JMA Best Track Data
of Tropical Storm Pulasan (2414) (in Japanese) {{DEFAULTSORT:Pulasan 2024 Pacific typhoon season 2024 disasters in the Philippines 2024 disasters in Japan 2024 disasters in South Korea 2024 disasters in China 2024 in Guam 2024 in the Northern Mariana Islands 2024 in Shanghai September 2024 in Oceania September 2024 in the United States September 2024 in Japan September 2024 in the Philippines September 2024 in South Korea September 2024 in China Typhoons in Guam Typhoons in the Northern Mariana Islands Typhoons in the Philippines Typhoons in Japan Typhoons in China Typhoons in South Korea September 2024 in North America 2024 in Canada