Severe Tropical Storm Nanmadol, known in 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 ...
as Severe Tropical Storm Emong, 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 southern
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 ...
during early-July 2017. Nanmadol developed over in 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 July 1, and strengthened into the third
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
2017 typhoon season on July 3. After gaining organization, the system rapidly developed and intensified into a severe tropical storm and reached its peak intensity with a 10-minute
maximum sustained wind
The maximum sustained wind associated with a tropical cyclone is a common
indicator of the intensity of the storm. Within a mature tropical cyclone, it is found within the eyewall at a certain distance from the center, known as the radius of ma ...
s of and a minimum
barometric pressure
Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1,013.2 ...
of . On July 4, Nanmadol turned eastwards and made
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 ...
near
Nagasaki
, officially , is the capital and the largest Cities of Japan, city of Nagasaki Prefecture on the island of Kyushu in Japan.
Founded by the Portuguese, the port of Portuguese_Nagasaki, Nagasaki became the sole Nanban trade, port used for tr ...
,
Kyushu
is the third-largest island of Japan's Japanese archipelago, four main islands and the most southerly of the four largest islands (i.e. excluding Okinawa Island, Okinawa and the other Ryukyu Islands, Ryukyu (''Nansei'') Ryukyu Islands, Islands ...
, just before it transitioned into an
extratropical cyclone
Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of p ...
.
Nanmadol dropped torrential rainfall across Kyushu, resulting in landslides, although the
Fukuoka
is the List of Japanese cities by population, sixth-largest city in Japan and the capital city of Fukuoka Prefecture, Japan. The city is built along the shores of Hakata Bay, and has been a center of international commerce since ancient times. ...
and
Ōita Prefectures were the hardest hit. The city of
Asakura, Fukuoka
file:Asakura city office.jpg, 270px, Asakura CIty Hall
is a Cities of Japan, city located in south central Fukuoka Prefecture, Japan. , the city had an estimated population of 50,488 in 22168 households, and a population density of 200 persons pe ...
experienced a one-day rainfall surpassing the city's average total for July by 50%, with a rainfall of recorded within a 12-hour period on July 5. Landslides were recorded in 44 different locations and flooding in 38 locations, and from this, more than 2,600 homes were destroyed. In total, 42 people died from Nanmadol due to drowning from flash flooding or due to landslides. Total damages was estimated to have toppled to
¥190 billion (US$1.68 billion).
The 2017 Typhoon Nanmadol is not to be confused with other
typhoons
A typhoon is a tropical cyclone that develops between 180° and 100°E in the Northern Hemisphere and which produces sustained hurricane-force winds of at least . This region is referred to as the Northwestern Pacific Basin, accounting for a ...
of the same name that also happened in the northwestern
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...
in
2004
2004 was designated as an International Year of Rice by the United Nations, and the International Year to Commemorate the Struggle Against Slavery and Its Abolition (by UNESCO).
Events January
* January 3 – Flash Airlines Flight 60 ...
,
2011
The year marked the start of a Arab Spring, series of protests and revolutions throughout the Arab world advocating for democracy, reform, and economic recovery, later leading to the depositions of world leaders in Tunisia, Egypt, and Yemen ...
, and
2022
The year began with another wave in the COVID-19 pandemic, with SARS-CoV-2 Omicron variant, Omicron spreading rapidly and becoming the dominant variant of the SARS-CoV-2 virus worldwide. Tracking a decrease in cases and deaths, 2022 saw ...
. The name Nanmadol was contributed by
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 refers to the
Nan Madol
Nan Madol is an archaeological site adjacent to the eastern shore of the island of Pohnpei, now part of the Madolenihmw district of Pohnpei state in the Federated States of Micronesia in the western Pacific Ocean. Nan Madol was the capital o ...
archaeological site on
Pohnpei
Pohnpei (formerly known as Ponape or Ascension, from Pohnpeian: "upon (''pohn'') a stone altar (''pei'')") is an island of the Senyavin Islands which are part of the larger Caroline Islands group. It belongs to Pohnpei State, one of the fou ...
.
Meteorological history
During June 30, a tropical disturbance developed about to the north-northeast of
Palau
Palau, officially the Republic of Palau, is an island country in the Micronesia subregion of Oceania in the western Pacific Ocean. The Republic of Palau consists of approximately 340 islands and is the western part of the Caroline Islands ...
. Noting some organization within the system, the
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 ...
(TCFA) early on July 1. Six hours later, 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 ...
(JMA) classified it as a tropical depression. Later that day, the JMA began to issue advisories, predicting that the system could intensify into a tropical storm within the next 24 hours. Shortly after, the
(PAGASA) upgraded the system to a tropical depression, assigning the local name ''Emong''.
Early on July 2, the JMA upgraded the system to a tropical storm, and assigned the official name ''Nanmadol''. The PAGASA also upgraded the system to a tropical storm. Soon after, the JTWC gave the system the internal designation of ''05W''. Satellite imagery depicted convective banding wrapping tightly into Nanmadol's
low-level circulation center
The eye is a region of mostly calm weather at the center of a tropical cyclone. The eye of a storm is a roughly circular area, typically in diameter. It is surrounded by the eyewall, a ring of towering thunderstorms where the most severe weath ...
(LLCC), prompting the JTWC to upgrade it to a tropical storm in their next advisory. Nanmadol later entered a favorable environment with low
vertical wind shear
Wind shear (; also written windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical o ...
and high
sea surface temperature
Sea surface temperature (or ocean surface temperature) is the ocean temperature, temperature of ocean water close to the surface. The exact meaning of ''surface'' varies in the literature and in practice. It is usually between and below the sea ...
s (SSTs) of , allowing it to develop a deep and symmetric core surrounded by deep
convection
Convection is single or Multiphase flow, multiphase fluid flow that occurs Spontaneous process, spontaneously through the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoy ...
. At this time, the JMA stated that Nanmadol had intensified into a severe tropical storm. The PAGASA also upgraded Nanmadol to a severe tropical storm in their final advisory on the system as it exited 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 ...
.
Nanmadol continued to intensify while moving northward just to the east of
Taiwan
Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...
, with
satellite imagery
Satellite images (also Earth observation imagery, spaceborne photography, or simply satellite photo) are images of Earth collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell im ...
capturing a small, developing
eye
An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system.
In higher organisms, the ey ...
. At 06:00 UTC on July 3, Nanmadol reached its peak intensity with the JTWC assessing the cyclone to have 1-minute sustained winds of ; the JMA estimated 10-minute sustained winds of and a minimum barometric pressure of . However, the JTWC assessed that Nanmadol reached its peak intensity as a Category 1-equivalent typhoon with 1-minute sustained winds of six hours later in a post-analysis report. Nanmadol maintained its peak intensity for several hours until just before July 4, when the system began curving eastwards and its satellite presentation deteriorated. Around that time, Nanmadol made landfall approximately to the east of
Nagasaki
, officially , is the capital and the largest Cities of Japan, city of Nagasaki Prefecture on the island of Kyushu in Japan.
Founded by the Portuguese, the port of Portuguese_Nagasaki, Nagasaki became the sole Nanban trade, port used for tr ...
in
Kyushu
is the third-largest island of Japan's Japanese archipelago, four main islands and the most southerly of the four largest islands (i.e. excluding Okinawa Island, Okinawa and the other Ryukyu Islands, Ryukyu (''Nansei'') Ryukyu Islands, Islands ...
. Despite the system still displaying a well-defined center, cloud tops began to warm, in line with the rapid weakening trend of the system. After several hours, Nanmadol began to interact with the mid-latitude westerlies; the JTWC downgraded the system further to a low-end of tropical storm intensity, though the JMA still maintained it at severe tropical storm intensity. By 21:00 UTC on the same day, the JTWC issued its final advisory on Nanmadol, mentioning that the system was embedded within the cold
baroclinic zone, and had thus lost its tropical characteristics and transitioned into a
cold-core low
A cold-core low, also known as an upper level low or cold-core cyclone, is a cyclone aloft which has an associated cold pool of air residing at high altitude within the Earth's troposphere, without a frontal structure. It is a low pressure syste ...
. The JMA soon followed suit with their final warning, declaring that Nanmadol had fully become an
extratropical cyclone
Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of p ...
at 00:00 UTC on July 5. Its extratropical remnants later left the basin on July 8.
Preparations, impact, and aftermath
The JMA issued a heavy rain warning for
Shimane Prefecture
is a Prefectures of Japan, prefecture of Japan located in the Chūgoku region of Honshu. Shimane Prefecture is the List of Japanese prefectures by population, second-least populous prefecture of Japan at 665,205 (February 1, 2021) and has a ge ...
and neighboring areas, in which the government had urged 20,000 residents to evacuate.
On July 3, the Sasebo City Emergency Management Bureau activated a total of 30 emergency shelters. The government dispatched a total of 12,000 rescuers, including police officers, firefighters and the Self-Defense Forces troops, in preparation for post-storm relief.
On July 10, the
Kyushu Railway Company
The , also referred to as , is one of the seven constituent companies of Japan Railways Group (JR Group). It operates intercity rail services within Kyushu, Japan. It formerly operated the Beetle (JR Kyushu), Beetle hydrofoil service across th ...
began a bus service to aid residents trapped in some areas along the currently suspended Kyudai Main Line; this included areas between Ukiha Station in Fukuoka Prefecture and Hita Station, Ōita Prefecture, where an iron bridge spanning a river was washed away by floodwaters. Due to the threat of further landslides, the
West Nippon Expressway Company
The , abbreviated as , is one of the main operators of expressways and toll roads in Japan. It is headquartered on the 19th floor of Dojima Avanza in Kita-ku, Osaka.
The company was established on October 1, 2005, as a result of the privatization ...
extended a closure of the
Ōita Expressway
is a Japanese expressway in Kyushu that travels from Tosu to Hiji, where it connects to the Higashikyushu Expressway. It runs through the southern half of Fukuoka Prefecture, and the northern half of Ōita Prefecture. The total length of Ōi ...
.
Trees with trunks of were washed away, blocking the water stream further and exacerbating floods. Therefore, on July 11, Forestry Minister
Yuji Yamamoto pledged to set up a task force to remove
driftwood
Driftwood is a wood that has been washed onto a shore or beach of a sea, lake, or river by the action of winds, tides or waves. It is part of beach wrack.
In some waterfront areas, driftwood is a major nuisance. However, the driftwood provides ...
. Meanwhile, an official at the
University of Hyogo
The is a public university in Kobe, Hyogo, Japan.
History
The University of Hyogo (UH) was established in April 2004 by integrating three universities which were run by Hyogo Prefecture government: , and the .
At its foundation, UH open ...
warned other municipalities of potential damage caused by fallen trees.

Peak windspeeds of were recorded in Nagasaki upon landfall, including a wind gust in the
Shikoku
is the smallest of the List of islands of Japan#Main islands, four main islands of Japan. It is long and between at its widest. It has a population of 3.8 million, the least populated of Japan's four main islands. It is south of Honshu ...
town of
Muroto just after 05:30 UTC.
Strong winds overturned vehicles, collapsed scaffolding, and left 68,500 homes without power in Nagasaki and
Kumamoto
is the capital Cities of Japan, city of Kumamoto Prefecture on the island of Kyushu, Japan. , the city has an estimated population of 738,907 and a population density of 1,893 people per km2. The total area is 390.32 km2.
had a populat ...
prefectures; other blackouts occurred in the prefectures of
Ōita,
Miyazaki and
Kagoshima
, is the capital Cities of Japan, city of Kagoshima Prefecture, Japan. , the city had an estimated population of 583,966 in 285,992 households, and a population density of 1100 persons per km2. The total area of the city is .
Etymology
While the ...
.
Around 3,000 airline passengers were affected by the grounding and cancellation of at least 47 flights. Heavy rains and strong winds disrupted numerous train services including the iconic ''
Shinkansen
The , colloquially known in English as the bullet train, is a network of high-speed railway lines in Japan. It was initially built to connect distant Japanese regions with Tokyo, the capital, to aid economic growth and development. Beyond lon ...
'', between
Hakata
is a ward of the city of Fukuoka in Fukuoka Prefecture, Japan.
Many of Fukuoka Prefecture and Fukuoka City's principal government, commercial, retail and entertainment establishments are located in the district. Hakata-ku is also the location o ...
and
Kagoshima-Chuo in
Kyushu
is the third-largest island of Japan's Japanese archipelago, four main islands and the most southerly of the four largest islands (i.e. excluding Okinawa Island, Okinawa and the other Ryukyu Islands, Ryukyu (''Nansei'') Ryukyu Islands, Islands ...
.
Evacuation advisories were issued to at least 20,000 residents due to fears of possible flooding and landslides, especially in the
Niigata,
Toyama Toyama may refer to:
Places
* Toyama Prefecture, a prefecture of Japan located in the Hokuriku region on the main Honshu island
* Toyama (city), the capital city of Toyama Prefecture
* Toyama Station, the main station of Toyama, Toyama
* Toyama Sta ...
and
Nagano prefectures that had experienced rainfall accumulations of up to in the preceding hours.
In
Hamada, Shimane
is a city located in Shimane Prefecture, Japan. , the city had an estimated population of 50,176 in 25498 households and a population density of 73 persons per km2. The total area of the city is .
Geography
Hamada is located in central Shim ...
, over fell in an hour.
At least three people were injured during the storm—a young boy's hand was injured when a school window broke in the city of
Kumamoto
is the capital Cities of Japan, city of Kumamoto Prefecture on the island of Kyushu, Japan. , the city has an estimated population of 738,907 and a population density of 1,893 people per km2. The total area is 390.32 km2.
had a populat ...
, and two adults in Ōita prefecture sustained injuries from falls as a result of the strong winds.
About 180 people took shelter at a junior high school gymnasium in
Asakura.
Within the prefecture, of rain fell in an hour, greatly contributing to a 24-hour rainfall total of . A later report showed that the prefecture experienced a total accumulated rainfall of .
The city of
Hita, Ōita
file:Hita city office.jpg, 270px, Hita City Hall
is a Cities of Japan, city located in Ōita Prefecture, Japan. , the city had an estimated population of 61,148 in 27,556 households, and a population density of 96 persons per km2. The total ar ...
also experienced extreme rainfall, with accumulations of . However the prefecture of
Fukuoka
is the List of Japanese cities by population, sixth-largest city in Japan and the capital city of Fukuoka Prefecture, Japan. The city is built along the shores of Hakata Bay, and has been a center of international commerce since ancient times. ...
experienced an incredible amount of of rain within the course of nine hours on July 5. Due to the risk of landslides, an evacuation order which covered 316 people from 115 households was issued in the Haki District of Asakura, due to high risk of landslides. Throughout the Fukuoka and Ōita Prefectures, 1,724 people evacuated.
More than 2,600 homes were destroyed by Nanmadol around the Fukuoka, Oita, and the Hiroshima prefectures,
but a later report showed a total of 4,458 buildings damaged.
Nearly a week after the flooding had begun, some roads were already reopened over in some communities in the Fukuoka Prefecture.
During July 12, the Japanese prime minister
Shinzō Abe
Shinzo Abe (21 September 1954 – 8 July 2022) was a Japanese politician who served as Prime Minister of Japan and President of the Liberal Democratic Party ( LDP) from 2006 to 2007 and again from 2012 to 2020. He was the longest-serving pri ...
canceled a trip to
Estonia
Estonia, officially the Republic of Estonia, is a country in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the Baltic Sea across from Sweden, to the south by Latvia, and to the east by Ru ...
for a European tour and instead visited devastated places over in the Kyushu region to view the damage and console residents. He also promised that the government would take action and do everything possible to help rebuild.
A total of 42 people have been confirmed dead due to torrential rains which caused landslides and flooding, particularly in
Kyushu
is the third-largest island of Japan's Japanese archipelago, four main islands and the most southerly of the four largest islands (i.e. excluding Okinawa Island, Okinawa and the other Ryukyu Islands, Ryukyu (''Nansei'') Ryukyu Islands, Islands ...
,
where two still remained missing and leaving 39 people injured.
Total damages in Japan were amounted to be
¥190 billion (US$1.68 billion).
See also
*
Weather of 2017
The following is a list of weather events that occurred in 2017.
Summary by weather type
Winter storms and cold waves
Winter weather in 2017 kicked off January 4–8, 2017 North American winter storm, with a winter storm from January 4-8. Th ...
*
Tropical cyclones in 2017
During 2017 tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, a total of 146 tropical cyclones had formed. 88 tropical cyclones h ...
*
Other tropical cyclones named Nanmadol
*
Other tropical cyclones named Emong
*
Tropical Storm Etau (2009)
Tropical Storm Etau was the deadliest tropical cyclone to impact Japan since Typhoon Tokage in 2004. Forming on August 8, 2009 from an area of low pressure, the system gradually intensified into a tropical storm. Tracking in a curved path ar ...
*
Typhoon Neoguri (2014)
*
Tropical Storm Etau (2015)
*
Typhoon Chaba (2016)
Typhoon Chaba, known in the Philippines as Super Typhoon Igme, was the fourth most intense tropical cyclone in 2016 and the strongest tropical cyclone to make landfall in South Korea since Sanba in 2012. Chaba also caused 7 deaths in the coun ...
*
Typhoon Talim (2017)
References
External links
JMA General Informationof Severe Tropical Storm Nanmadol (1703) from Digital Typhoon
JMA Best Track Dataof Severe Tropical Storm Nanmadol (1703)
05W.NANMADOL from the U.S. Naval Research Laboratory
{{DEFAULTSORT:Nanmadol (2017)
2017 Pacific typhoon season
Articles containing video clips
July 2017 in Japan
Typhoons in Japan
Nanmadol