2013 Pacific typhoon season

Below the pace, then above it

Early forecasts pointed to a near-normal year. In May, Tropical Storm Risk expected about 26 tropical storms and 16 typhoons, close to its 1965 to 2012 average of 26.1 tropical storms, 16.3 typhoons and an accumulated cyclone energy of 295. By August the season was running about 60 percent behind its usual year-to-date activity, with only one or two typhoons through July, and the group cut its outlook to 22 tropical storms, 13 typhoons and an energy total near 230.

The autumn erased that deficit. The site's archive puts the season's accumulated cyclone energy, which combines storm strength and duration, at 277.8. The Joint Typhoon Warning Center called 2013 the first year of above-average western North Pacific activity since 2004, with 33 cyclones against a long-term average of 31, and counted five storms that reached its super typhoon threshold of 130 knots.

How the season unfolded

Activity began in January, well outside the usual peak. Tropical Storm Sonamu organized southwest of Guam, crossed Mindanao as a depression and strengthened over the Sulu Sea before fading west of Bintulu, Sarawak, on January 10. Shanshan followed in February as a weak depression near the southern Philippines, and then nothing formed until June, when Yagi, Leepi and Bebinca stayed at tropical storm strength.

Typhoon Rumbia became the season's first typhoon on July 1, and Typhoon Soulik intensified rapidly a week later. August brought Typhoon Utor and Typhoon Trami, but by mid-September only four of the season's 16 typhoons had formed. The rest of the year made up for it: 12 typhoons reached that strength after mid-September, including nine of the 11 major typhoons. Usagi, Pabuk, Wutip and Fitow followed each other through late September, and October added Danas, Nari, Wipha, Francisco, Lekima and Krosa.

Typhoon Haiyan formed in early November. Around the same time, a system the Japan Meteorological Agency never named, called Wilma in the Philippines, drifted west from near Palau across Mindanao and Vietnam and eventually reached the Arabian Sea. Its 474 recorded hours make it the longest-tracked system in the archive this year. Tropical Storm Podul affected the Philippines and Vietnam in mid-November, and a short-lived depression on December 3 and 4 closed the season.

Three Category 5 typhoons

Typhoon Haiyan was the strongest storm of the season and among the strongest on record in the basin. The archive gives it a peak one-minute wind of 170 knots and a pressure of 895 hPa on November 7 as it approached the Philippines. The Joint Typhoon Warning Center found sea surface temperatures above 29°C along its path, deep ocean warmth and low wind shear, and all three satellite fixing agencies rated its structure at T8.0, the top of the Dvorak scale, that day.

Typhoon Francisco and Typhoon Lekima both reached Category 5 in October with 140-knot winds and 918 hPa, three days apart and over open water. Francisco passed south of Guam before curving toward Japan, and Lekima strengthened north of Micronesia before recurving. Neither center crossed land.

Five more typhoons reached Category 4. Typhoon Usagi peaked at 135 knots on September 19 before weakening between Luzon and Taiwan, Typhoon Utor at 130 knots on August 11 shortly before striking Luzon, and Typhoon Soulik at 125 knots on July 10. Typhoon Danas and Typhoon Wipha each peaked at 120 knots in October, Danas while passing the Ryukyu Islands and Wipha before it weakened over cooler water near Japan.

Haiyan in the Philippines

Haiyan, known in the Philippines as Yolanda, formed south of Pohnpei and intensified from 70 to 130 knots in the 24 hours to November 6. It passed over Kayangel in Palau at about 150 knots, then struck Guiuan in Eastern Samar late on November 7 UTC before crossing Leyte near Tolosa. The Joint Typhoon Warning Center estimated its landfall wind from satellite at 165 knots.

Wind and storm surge devastated Samar and Leyte. The Philippine National Disaster Risk Reduction and Management Council reported 6,300 deaths, about 93 percent of them in Eastern Visayas, and the warning center's report cites more than 28,000 people injured and over 1,700 missing. Haiyan was the deadliest typhoon in modern Philippine records.

The storm emerged over the South China Sea at about 120 knots, turned north and came ashore in northeastern Vietnam at typhoon strength on November 10 before dissipating over southern China. Fourteen people died indirectly in Vietnam. Flooding in mainland China killed 30 and caused about 4.58 billion yuan (US$750 million) in damage in 2013 values.

Other landfalls and impacts

Typhoon Soulik struck northern Taiwan on July 12 and then Fujian, leaving about 800,000 people without power in Taiwan. It killed 4 people there and 11 in eastern China. In August, Typhoon Utor hit Casiguran in Aurora province, where about 80 percent of structures were reported destroyed, before landing in Guangdong as a weaker typhoon; its total toll was 97 deaths and US$3.55 billion in damage in 2013 dollars. Later that month, heavy rain linked to Trami flooded Metro Manila and nearby provinces, where 18 people died, before the storm came ashore in Fujian.

Typhoon Usagi made landfall near Shanwei, Guangdong, on September 22 and caused at least US$4 billion in total damage in 2013 dollars. Typhoon Wutip sank three fishing boats near the Paracel Islands, leaving 74 fishermen missing, and its toll across Southeast Asia reached 77 deaths, 42 of them in Vietnam. In early October, Typhoon Fitow crossed the southern Ryukyu Islands and struck the Fujian and Zhejiang coast, flooding 70 percent of downtown Yuyao. Its total damage of more than US$10 billion in 2013 dollars made it China's costliest storm up to that time.

Typhoon Nari made landfall at Dingalan, Aurora, around October 11 and reached Vietnam on October 14; in the Philippines it killed 15 people and caused losses of 12.3 billion pesos (about US$277 million) in 2013 values. Typhoon Wipha brought heavy rain to Japan in mid-October and killed 41 people there. Typhoon Krosa crossed northern Luzon at Santa Ana, Cagayan, on October 31, damaging more than 37,000 houses and killing four people in the Philippines.

How the counts compare

The Japan Meteorological Agency, which names storms using ten-minute winds, counted 31 tropical storms and 13 typhoons. Its total includes Pewa and Unala, which crossed from the central Pacific, and Yutu, which has no US-agency wind estimate in the archive. Ten-minute winds also run lower than one-minute winds, so Trami and Pabuk were severe tropical storms in the Japanese analysis but typhoons in US estimates, while Man-yi was a Japanese typhoon but peaked at 60 knots in US data.

The Joint Typhoon Warning Center issued warnings on 33 western North Pacific cyclones. The site's archive counts one-minute winds over each storm's whole tropical stage, so its totals of 28 tropical storms and 16 typhoons include Lehar, which began as a depression over the Malay Peninsula, crossed 100°E into the North Indian Ocean on November 22 and reached typhoon-strength winds in the Bay of Bengal.

The Typhoon Committee retired four names after the season: Sonamu, Utor, Fitow and Haiyan, replaced in 2015 by Jongdari, Barijat, Mun and Bailu. The Philippine weather service, which named 25 systems in its area, its most since 2004, retired Labuyo, Santi and Yolanda, the local names for Utor, Nari and Haiyan.