2005 Pacific typhoon season

Season overview

By number of storms, 2005 was a below-average year in the western Pacific. The Joint Typhoon Warning Center counted 25 tropical cyclones, of which 24 reached tropical storm strength, against a 1959 to 2005 average of about 26 tropical storms and typhoons a year. Yet 18 of those storms became typhoons, just above the long-term mean of 17.7, and 10 reached major typhoon strength. The archive's accumulated cyclone energy of 308.8 sits close to the 1965 to 2004 average of 305 used by the Tropical Storm Risk consortium, a sign that the season made up in intensity what it lacked in numbers.

Seasonal forecasters had expected roughly normal activity with a slightly above-average share of intense typhoons. Tropical Storm Risk pointed to weaker trade winds across much of the basin and enhanced cyclonic spin over the northwest Pacific, and later noted that Pacific sea surface temperatures were running warmer than it had anticipated in May. Most of the damaging storms tracked west or northwest toward Taiwan, eastern China and the Ryukyu Islands; eight typhoons passed near Okinawa, a little more than usual, as several moved through the Sakishima Islands on their way to Taiwan or China.

How the season unfolded

The year began early. Typhoon Kulap formed southwest of Chuuk on January 13, dropping around 300 mm of rain on the island over two days, and reached 65 kt on January 17 before turning north and weakening. Typhoon Roke followed in March, crossing into the eastern Visayas on March 16, and Typhoon Sonca peaked at 115 kt over open water in late April. Typhoon Nesat, which formed south-southeast of Guam at the end of May, became the longest-lived storm in the archive, with nearly 15 days of recorded positions; it reached 125 kt near the Philippines on June 3 but curved away to the northeast without striking land.

After a quiet stretch in June and early July, the season came alive in mid-July with Typhoon Haitang, followed within two weeks by Tropical Storms Nalgae, Banyan and Washi and then Typhoon Matsa. August was the busiest month: the Joint Typhoon Warning Center attributed six storms to it, and every one of them, Matsa, Sanvu, Mawar, Guchol, Talim and Nabi, became a typhoon. Mawar and Guchol were active side by side in the open Pacific in late August, while Talim and Nabi overlapped at the turn of the month.

September kept the pace with Typhoon Khanun, Tropical Storm Vicente, Typhoon Saola, Typhoon Damrey and Typhoon Longwang, which carried the season's intense phase into early October. Typhoon Kirogi reached 115 kt far from land in mid-October, and Typhoon Kai-Tak crossed the South China Sea to Vietnam at the start of November. Tropical Storm Tembin and Typhoon Bolaven both reached the northern Philippines in November, and a short-lived, unnamed tropical storm off northern Borneo, which the Philippine weather service called Quedan, closed the season on December 21.

Strongest storms

Two storms share the top of the archive at 140 kt one-minute winds and 898 hPa, both Category 5. Typhoon Haitang, the season's strongest in the archive, reached that peak on July 16 while tracking west toward Taiwan and the Sakishima Islands. Typhoon Nabi matched it on September 1 after passing north of Saipan, before turning north toward Japan. The Japan Meteorological Agency also ranked Haitang first, with a central pressure of 920 hPa and ten-minute winds of about 105 kt.

Typhoon Talim came next at 130 kt and 910 hPa on August 30, making it the third super typhoon of the year in the Joint Typhoon Warning Center's classification. Typhoons Nesat, Mawar and Longwang each peaked at 125 kt, and Longwang developed annular characteristics, a symmetrical, long-lasting structure, on its way to Taiwan. Typhoons Sonca, Khanun and Kirogi reached 115 kt and Typhoon Saola 100 kt, rounding out the ten major typhoons.

Taiwan and eastern China

China bore the brunt of the season, with eight typhoons striking the country. Typhoon Haitang had weakened before it came ashore near Hualien, Taiwan, on July 18, but its slow, day-long crossing of the island's mountains brought flash floods and landslides. It made a second landfall near Wenzhou on July 19, and its damage across Taiwan and China exceeded US$1.1 billion in 2005 dollars. Typhoon Matsa passed over the Yaeyama Islands and struck Zhejiang on August 6 with sustained winds near 145 km/h, leaving 25 people dead and about $2.23 billion in damage (2005 US dollars).

Typhoon Sanvu crossed a peninsula of Cagayan in northern Luzon before reaching China on August 13, where it caused 36 deaths. Typhoon Talim made landfall as a Category 3 storm on August 31 and weakened over southeastern China, where it caused 167 deaths, including at least 40 in landslides in Anhui; five more people died in Taiwan. In September, more than 800,000 people were evacuated as Typhoon Khanun made landfall near Taizhou, Zhejiang, about 220 km south of Shanghai, causing about $1.22 billion in damage (2005 US dollars).

Typhoon Damrey struck Wanning on Hainan on September 25 with sustained winds up to 180 km/h, the strongest typhoon to hit the island since Typhoon Marge in 1973. It knocked out power across the province, killed at least 16 people in China and went on to northern Vietnam; its total toll across the Philippines, China, Vietnam and Thailand is put at 179 deaths. Typhoon Longwang then came ashore south of Hualien on October 2 as a Category 4 storm and reached Fujian as a minimal typhoon that evening. It killed one person in Taiwan and 149 people in total, mostly in China, and about $963 million in damage (2005 US dollars).

Japan and Korea

Three typhoons made landfall in Japan, close to the average of 2.6. Tropical Storm Banyan brushed the southern and eastern coasts of Honshu in late July, and Typhoon Mawar came ashore on Honshu on August 25 as a Category 2 storm, killing one person and injuring seven. Typhoon Saola stayed offshore but brought heavy rain to Japan in late September, and Typhoon Khanun lashed the Sakishima Islands on election day, when some polling stations changed their opening hours.

Typhoon Nabi was the season's most destructive storm in Japan. It damaged or destroyed 114 homes in the Northern Marianas, with losses of about US$2.5 million in 2005 currency, then passed east of Okinawa and reached Kagoshima Prefecture on September 6 as a Category 2 storm. About 250,000 people evacuated on Kyushu, rainfall reached 1,322 mm over three days, and the storm set 61 daily rainfall records. Nabi killed 29 people in Japan and caused ¥94.9 billion in damage in 2005 currency, and six more people died in South Korea.

The Philippines and Vietnam

The Philippines escaped the worst of the season. Typhoon Roke killed seven people there in March and caused about $166,000 in damage (2005 US dollars). Tropical Storm Tembin made landfall in the northern Philippines on November 11, and Typhoon Bolaven, which briefly reached typhoon strength on November 17, weakened to a tropical storm before coming ashore in the Cagayan Valley on November 20.

Vietnam was struck repeatedly from the South China Sea. Tropical Storm Washi crossed Hainan and the Gulf of Tonkin to reach Nam Dinh at the end of July, and Tropical Storm Vicente came ashore northwest of Hue on September 18, leaving about five people dead or missing in Vietnam. Typhoon Kai-Tak made landfall north of Hue on November 2, killing at least 19 people and leaving 10 missing, with damage of at least $11 million (2005 US dollars).

How the counts compare

The site's counts use one-minute winds from US agencies and match the Joint Typhoon Warning Center's 24 tropical storms and 18 typhoons. The Japan Meteorological Agency, which uses ten-minute winds, named 23 storms and classed 13 as typhoons. The December storm off Borneo reached 45 kt in the one-minute record but was tracked only briefly as a depression by JMA and never named. Kulap, Roke, Sanvu, Guchol and Bolaven all reached 65 to 80 kt one-minute winds but peaked as severe tropical storms on JMA's scale. That is why JMA's first typhoon of the year was Haitang on July 13, while the one-minute record already had Kulap at typhoon strength in January.

The archive also holds a tropical depression, 20W, which brought over 230 mm of rain to parts of Hainan in October, and a brief unnamed system in September with no recorded winds; neither counts as a tropical storm. Vietnam's national forecasting centre went further in the other direction, treating two August depressions as tropical storms. The Joint Typhoon Warning Center issued 26 formation alerts in 2005, tied for the fewest in its 1976 to 2005 record, and every one of the year's 25 cyclones was preceded by an alert.

After the season, the Typhoon Committee retired the names Matsa, Nabi and Longwang, replacing them with Pakhar, Doksuri and Haikui. The Philippine weather service retired none of its 2005 names, though the unused Undang was later changed to Urduja because it had already been retired in 1984.