The 2002 Pacific typhoon season was a slightly above average Pacific typhoon season, producing twenty-six named storms, with fifteen becoming typhoons, and eight intensifying into super typhoons. It was an event in the annual cycle of tropical cyclone formation, in which tropical cyclones form in the western Pacific Ocean. The season ran throughout 2002, though most tropical cyclones typically develop between May and November. The season's first named storm, Tapah, developed on January 11, while the season's last named storm, Pongsona, dissipated on December 11. The season's first typhoon, Mitag, reached typhoon status on March 1, and became the first super typhoon of the year four days later.
The scope of this article is limited to the Pacific Ocean to the north of the equator between 100°E and the 180th meridian. Within the northwestern Pacific Ocean, there are two agencies which assign names to tropical cyclones which can often result in a cyclone having two names. The Japan Meteorological Agency (JMA) will name a tropical cyclone if it has 10-minute sustained wind speeds of at least 65 km/h (40 mph) anywhere in the basin, while the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) assigns names to tropical cyclones which are active in the Philippine Area of Responsibility (PAR), located between 135°E-115°E and between 5°N–25°N, regardless of whether or not a tropical cyclone has already been given a name by the JMA. Tropical depressions that are monitored by the United States' Joint Typhoon Warning Center (JTWC) are given a number with a "W" suffix.
Seasonal forecasts
On March 6, meteorologists from University College London at Tropical Storm Risk issued a forecast for above-average activity during the season, citing slightly warmer-than-usual sea surface temperatures. The group used data from the JTWC and compared their projection of 28.6 storms with the 30-year average of 26.3. They raised the prediction to 29.6 storms in April, and again to 30.5 in early May. Ultimately, they overestimated the number of storms. The Laboratory for Atmospheric Research at the City University of Hong Kong also issued a season forecast in April 2002, predicting 27 storms with a margin of error of 3, of which 11 would become typhoons, with a margin of error of 2. The agency cited a stronger-than-normal subtropical ridge over the Pacific Ocean and ongoing El Niño conditions as factors favoring development, but anticipated below-normal activity in the South China Sea. These predictions proved to be largely accurate.
During the year, the JMA issued advisories on tropical cyclones west of the antimeridian to the Malay Peninsula, and north of the equator, in its role as the official Regional Specialized Meteorological Center, a designation it received from the World Meteorological Organization in 1989. The JMA produced forecasts and analyses every six hours, beginning at 00:00 UTC, using numerical weather prediction (NWP) models and a climatological tropical cyclone forecast model. They also applied the Dvorak technique with NWP to estimate 10-minute sustained winds and barometric pressure. The JTWC issued warnings for storms within the basin as well, operating from Pearl Harbor in Hawaii and supplying forecasts to the United States Armed Forces in the Indian and Pacific Oceans. In 2002, the agency moved its backup facility from Yokosuka, Japan to Monterey, California. Several meteorologists departed the agency near the start of the year, though new forecasters compensated for their inexperience by relying on consensus among various forecast models. That year, the JTWC also began experimenting with five-day forecasts.
Season summary
The season was active, with many tropical cyclones affecting Japan and China. Every month had tropical activity, with most storms forming from July through October. Overall, there were 44 tropical depressions declared officially or unofficially, of which 26 became named storms. Of those, 15 became typhoons, equivalent to a minimal hurricane, while 8 of the 15 typhoons intensified into super typhoons unofficially according to the JTWC. The season began early with the first storm, Tapah, developing on January 10 east of the Philippines. Two months later, Typhoon Mitag became the first super typhoon ever recorded in March. In June, Typhoon Chataan dropped heavy rainfall in the Federated States of Micronesia, killing 48 people and becoming the deadliest natural disaster in the state of Chuuk. Chataan later caused extensive damage in Guam before striking Japan. In August, Typhoon Rusa became the deadliest typhoon in South Korea in 43 years, causing 238 deaths and $4.2 billion in damage. Typhoon Higos in October was the fifth-strongest typhoon to strike Tokyo since World War II. The final typhoon of the season was Typhoon Pongsona, which was one of the costliest storms on record in Guam; it caused $700 million in damage on the island before dissipating on December 11.
Despite an early beginning, widespread activity did not occur until June, when six storms passed near or over Japan after a ridge weakened. Nine storms developed in July, many of which influenced the monsoon trough over the Philippines that produced heavy rainfall and deadly flooding. The flooding was worst in Luzon, where 85 people were killed. The series of storms caused widespread closures of schools and offices. Many roads were damaged, and the floods caused about $1.8 million (₱94.2 million) in crop losses, largely to rice and corn. Overall damage from the series of storms was estimated at $10.3 million (₱522 million). From June to September, heavy rainfall affected large portions of China, resulting in devastating flooding that killed over 1,500 people and left $8.2 billion (CN¥68 billion) in damage. During this time, Tropical Storm Kammuri struck southern China with a large area of rainfall that damaged or destroyed 245,000 houses. A total of 153 deaths were connected to the storm, mostly inland in Hunan, and damage totaled $322 million (CN¥2.665 billion). Activity shifted farther east after September, with Typhoon Higos striking Japan in October and Typhoon Pongsona hitting Guam in December.
During most of the year, sea surface temperatures were above normal near the equator, and were highest around 160°E from January to July, and in November. Areas of convection developed farther east than usual, causing many storms to develop east of 150°E. The average point of formation was 145.9°E, the easternmost point since 1951. As a result, no tropical storms made landfall in the Philippines, the first such occrrence since 1951, according to the JMA. Two hurricanes – Ele and Huko – entered the basin from the Central Pacific, east of the International Date Line. Overall, there were 26 named storms in the basin in 2002, which was slightly below the norm of 26.7. A total of 15 of the 26 storms became typhoons, a slightly higher-than-normal proportion.
The ACE index for the 2002 Pacific typhoon season, as calculated by Colorado State University using data from the JTWC, was 390.6 units.
Systems
Tropical Storm Tapah (Agaton)
The first storm of the season formed on January 9 near Palau. It developed from the monsoon trough and was first observed by the JTWC two days before its formation. The system initially consisted of an area of convection with a weak circulation, located in an area of weak wind shear. On January 10, the JMA classified the system as a tropical depression. On that same day, the JTWC initiated advisories on the depression and designated it 01W, while PAGASA assigned it the local name Agaton. The storm moved west-northwestward due to a ridge to the north, and the system gradually became better organized. On January 12, the JMA upgraded the depression into a tropical storm and named it Tapah. Later that day, the agency estimated Tapah's sustained winds of 75 km/h (45 mph). Around that time, Tapah developed an eye feature beneath its convection, prompting both the JTWC and PAGASA to upgrade its sustained winds intensity to a peak of 95 km/h (60 mph). An approaching trough weakened the ridge, which drifted the storm northwest. Due to increasing wind shear, convection gradually weakened, and the JMA downgraded Tapah to a tropical depression on January 13; however, other agencies maintained the system at tropical storm status. Tapah dissipated along the eastern coast of Luzon in the Philippines on the following day.
Typhoon Mitag (Basyang)
The typhoon originated from a trough near the equator on February 25, near Micronesia. It moved westward through the archipelago and intensified into a typhoon, before passing near Yap on March 2. High winds and heavy rainfall affected the state, causing an islandwide power outage and destroying hundreds of houses. Mitag severely damaged crops, resulting in food shortages. The rainfall and storm surge flooded much of the coastline as well as Yap's capital, Colonia. Damage totaled $150 million, mostly to crops. There was one death related to the storm's aftermath.
After affecting Yap, Mitag turned northwestward and later northward due to an approaching trough. It passed north of Palau, killing one person there. Despite predictions of weakening, the typhoon continued to intensify, reaching its peak intensity with 10-minute sustained winds of 175 km/h (110 mph) on March 5. The JTWC estimated peak one-minute sustained winds of 260 km/h (160 mph) when the storm was approximately 610 km (380 mi) east of Catanduanes in the Philippines, making Mitag a super typhoon, the first one on record in the month of March. The combination of cooler air and interaction with the westerlies caused Mitag to weaken significantly, and four days later, the storm dissipated east of the Philippines.
Typhoon Hagibis
The monsoon trough spawned a tropical disturbance near the Caroline Islands in mid-May. By that time, the system was an area of convection with a weak circulation, although the system organized as outflow improved. It tracked northwestward within the monsoon trough, steered by a mid-level ridge. The system developed into a tropical depression on May 14 about 500 km (310 mi) southwest of Chuuk Lagoon, and early the next day the JTWC initiated advisories. For several days the depression remained weak, until it intensified into a tropical storm named "Hagibis" on May 16, about 200 km (120 mi) southwest of Guam. The developing storm dropped rainfall on Guam that ended the island's wildfire season. The storm quickly intensified, developing an eye feature later that day. Early on May 18, the JMA upgraded Hagibis into a typhoon, and around that time, an approaching trough turned the storm to the northeast.
While accelerating northeastward, Hagibis developed a well-defined eye and underwent a period of rapid deepening. On May 19, the JMA estimated peak 10-minute winds of 175 km/h (109 mph), and the JTWC estimated 1-minute winds of 260 km/h (160 mph); this made Hagibis become a second super typhoon after Mitag. At the time of its peak, the typhoon was located about 305 km (190 mi) west-southwest of the Northern Mariana Islands. Hagibis only maintained its peak for about 12 hours, after which the eye began weakening. The trough that caused the typhoon's acceleration also caused the storm to lose tropical characteristics, and dry air gradually became entrained in the circulation. On May 21, Hagibis became extratropical to the east of Japan after having weakened below typhoon intensity. The remnants continued to the northeast and dissipated south of the Aleutian Islands on May 22.
Severe Tropical Storm Noguri (Espada)
In early June, a disturbance within the monsoon trough persisted in the South China Sea to the east of Vietnam. On June 4, a tropical depression developed just off the east coast of Hainan, with a broad circulation and scattered convection. The system tracked slowly eastward due to a ridge to the north, and conditions favored intensification, including favorable outflow and minimal wind shear. The JTWC initiated advisories on June 6, and despite the favorable conditions, the depression remained weak. On June 7, the system briefly entered the Philippine Area of Responsibility, and PAGASA named it as "Espada". Later that day, the JTWC upgraded the depression to a tropical storm, and on June 8 the JMA upgraded the depression into "Noguri", halfway between Taiwan and Luzon. Increased outflow from an approaching trough allowed the storm to quickly intensify. The JTWC upgraded Noguri into a minimal typhoon late on June 8, after an eye developed. By that time, the storm was moving to the northeast due to a building ridge to the southeast. The JMA only estimated peak 10-minute winds of 110 km/h (68 mph), making Noguri become a severe tropical storm. However, the JTWC estimated peak winds of 160 km/h (99 mph), after the eye became well-organized. Increasing wind shear weakened Noguri, and the storm passed just west of the Miyako-jima on June 9. The convection diminished, and the JTWC declared Noguri as extratropical while the storm was approaching on Japan. The JMA continued tracking the storm until it dissipated over the Kii Peninsula on June 11.
While passing the south of Taiwan, it dropped heavy rainfall peaking at 320 mm (13 in) in Pingtung County. Rainfall in Japan peaked at 123 mm (4.8 in) at a station in Kagoshima Prefecture. The threat of the storm prompted school closures and 20 airline flight cancellations. Noguri injured one person, damaged one house, and caused about $4 million (¥504 million JPY) in agricultural damage.