2018 Pacific typhoon season

Season overview

By total energy 2018 was a highly active year. The site's archive gives an accumulated cyclone energy (ACE) of 356.5, well above the 1965 to 2017 average of 294 used by the Tropical Storm Risk consortium, and the Joint Typhoon Warning Center (JTWC) ranked the basin's ACE as the third highest since 2000. Much of that energy came from long-lived super typhoons, above all Mangkhut and Yutu, which held extreme intensity for days over open water.

Ocean and atmosphere offered no strong push either way. JTWC described the year as close to ENSO-neutral: a weak La Niña signal at the start of the year faded to neutral conditions over the summer and gave way to weak warm anomalies by December. Storms formed in the areas typical of such a year. Tropical Storm Risk had expected a slightly above-average season, forecasting 27 tropical storms, 17 typhoons and an ACE of around 307 in May, later raising the ACE outlook to 331 before trimming it to 319 in August.

JTWC warned on 36 tropical cyclones in the basin, one standard deviation above its 25-year mean of 30, and attributed the surplus mostly to extra tropical storms. Its tally of 16 typhoons was close to the long-term mean, but seven reached its super typhoon threshold of 130 knots, against an average of five.

How the season unfolded

The season began before the calendar year did. Tropical Storm Bolaven formed northeast of Palau on 29 December 2017 and crossed the central Philippines as a depression, known locally as Agaton, before briefly reaching tropical storm strength over the South China Sea on 3 January. Tropical Storm Sanba followed in February and came ashore in Surigao del Sur on Mindanao. In late March Typhoon Jelawat became the year's first typhoon on 29 March and then intensified explosively to a peak of 130 knots far out over the open Pacific, an unusually powerful storm for so early in the year.

After a short tropical storm in May, activity picked up in June. Tropical Storm Ewiniar came ashore in southern China, and Tropical Storm Maliksi strengthened the southwest monsoon over the Philippines without making landfall. Typhoon Prapiroon struck Japan and affected South Korea at the start of July, the first storm to affect the Korean Peninsula since 2013. It was quickly followed by Typhoon Maria, which passed over Guam as a tropical storm and then intensified from tropical storm to Category 5 strength in less than a day.

From mid-July the basin grew crowded. Tropical Storm Son-Tinh and Tropical Storm Ampil were followed by Typhoon Wukong and Typhoon Jongdari, whose rare looping track carried it westward into Japan from the Pacific side. August was the busiest month of the year, with eight storms reaching tropical storm strength. On 16 August JTWC was tracking six circulations at once, from Tropical Storm Bebinca in the South China Sea and the remnants of Tropical Storm Yagi over China to Tropical Storm Rumbia near Korea, Typhoon Soulik northwest of Guam, the disturbance that became Typhoon Cimaron, and the remains of Hurricane Hector near the Date Line.

The late summer and autumn belonged to a series of violent typhoons. Typhoon Jebi formed at the end of August, Typhoon Mangkhut and Tropical Storm Barijat in early September, and Typhoon Trami and Typhoon Kong-Rey in late September. After a lull in the first half of October, Typhoon Yutu formed near the Marshall Islands on 21 October and became the season's sixth Category 5 storm.

November activity shifted south and west. Typhoon Usagi, whose precursor had drifted in from the central Pacific, crossed the Philippines as a depression and later reached Vietnam's Mekong Delta, while Toraji, which the Japan Meteorological Agency (JMA) named but which peaked at 30 knots in the US-agency winds the site uses, struck southern Vietnam. Typhoon Man-Yi turned an anticyclonic loop east of the Philippines without reaching land. A late-December depression, called Usman in the Philippines, crossed Samar and Palawan, and its remnants fed the circulation that became Tropical Storm Pabuk on the last day of the year. Pabuk's final tropical observation on 7 January 2019 closes the season in the archive.

Six Category 5 typhoons

Six storms reached Category 5 intensity, the first time the basin had produced so many since 2014: Maria, Jebi, Mangkhut, Trami, Kong-Rey and Yutu. Maria led off in early July with a peak of 145 knots on 8 July, and it was the first Category 5 in the western Pacific since Typhoon Nock-ten in 2016.

Typhoon Jebi was the site's strongest storm of the season, with one-minute winds of 155 knots and a pressure of 907 hPa on 31 August, shortly after passing the Northern Mariana Islands. Typhoon Mangkhut matched its 155-knot winds on 12 September and went deeper, to 896 hPa, the lowest pressure of the season. Yutu reached 150 knots and 904 hPa on 24 October, Kong-Rey 150 knots and 906 hPa on 1 October, and Trami 140 knots on 24 September.

Kong-Rey's peak also coincided with Hurricane Walaka at Category 5 strength in the central Pacific, the first time since 2005 that two Category 5 storms had been active at once in the Northern Hemisphere. Mangkhut and Yutu stood out for how long they held super typhoon strength, and JTWC credited them with much of the season's high ACE.

Notable landfalls and impacts

Japan had one of its most battered seasons in years. JTWC counted five tropical cyclones crossing mainland Japan and two crossing South Korea. Typhoon Jebi struck Shikoku and then the Kobe area on 4 September, the strongest typhoon to hit Japan since 1993. Storm surge flooded Kansai International Airport, and a tanker driven into the airport's access bridge cut it off from the mainland. Fourteen people died in Japan, and insured losses were estimated at US$13 to 14 billion. Typhoon Trami followed on 30 September near Tanabe in Wakayama Prefecture, where four people died and insured losses reached about 306 billion yen, roughly US$2.69 billion in 2018 dollars.

In the Northern Mariana Islands, Typhoon Yutu passed directly over Tinian on 25 October local time with sustained core winds of 150 knots, according to JTWC, the most powerful storm on record there. Thousands of homes on Tinian and Saipan were destroyed, more than 200 power poles fell, and two women died on Saipan. Losses in the islands exceeded US$800 million. Yutu later struck Isabela on Luzon as Typhoon Rosita, where flooding and landslides caused further deaths.

Typhoon Mangkhut, known in the Philippines as Ompong, came ashore at Baggao in Cagayan late on 14 September UTC at Category 5 strength. The typhoon then passed near Hong Kong, where the Observatory raised its highest warning signal, before a final landfall in southern China. At least 134 deaths were attributed to Mangkhut as of late September 2018, 127 of them in the Philippines, where damage was estimated at 33.9 billion pesos, about US$627 million. Combined damage across its path is estimated at US$3.77 billion in 2018 dollars.

Some of the deadliest storms were weak ones. Tropical Storm Rumbia's rains flooded eastern China in August, killing 53 people and causing economic losses of 36.91 billion yuan, about US$5.36 billion; the vegetable-growing city of Shouguang in Shandong was hit hardest. Flooding in North Korea triggered by Typhoon Soulik killed 86 people. The late-December depression called Usman triggered landslides in the Philippines that killed 156 people, with damage of 5.41 billion pesos, about US$103 million. Toraji's floods killed 20 people around Nha Trang in Vietnam.

Monsoon rains added a heavy toll between storms. By 1 August, flooding during the enhanced southwest monsoon of July had killed 16 people in the Philippines, with damage of 4.66 billion pesos, about US$87.4 million. In northern Vietnam, Tropical Storm Son-Tinh's lingering rains flooded Hanoi and nearby provinces, with economic losses of about US$287 million, and Tropical Storm Ewiniar killed 13 people in southern China, where losses reached 5.19 billion yuan, about US$812 million. All figures are those reported for each storm in 2018 currency; they are not combined into a season total here.

Counts, names and records

Agency counts for 2018 differ because each measures something different. The site's 30 tropical storms and 16 typhoons come from US-agency one-minute winds in the international best-track archive, which is why they match JTWC's own totals of 30 and 16. JMA, the official regional center, uses ten-minute winds, which run lower than one-minute values for the same storm, and recorded 29 tropical storms and 13 typhoons. JMA's total includes Hurricane Hector, which crossed the Date Line from the central Pacific in August and is not among the 36 storms on this page. JTWC's seven super typhoons against the site's six Category 5 storms reflects thresholds: Typhoon Jelawat peaked at 130 knots, enough for super typhoon status but just below Category 5.

The year's end also falls differently by agency. JTWC began warnings on Pabuk as a depression on 31 December and kept it in its 2018 records, while JMA named it on 1 January 2019 as the first storm of the following season.

After the season the Typhoon Committee retired the names Rumbia, Mangkhut and Yutu, replacing them with Pulasan, Krathon and Yinxing. The Philippine weather service retired Ompong, Rosita and Usman, the local names of Mangkhut, Yutu and the December depression, because each caused at least one billion pesos in damage.