The 2012 Pacific typhoon season was the second consecutive season to be a deadly and destructive season, primarily due to Typhoon Bopha which killed 1,901 people in the Philippines. It was a slightly above average season that produced 25 named storms, fourteen typhoons, and four 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 2012, though most tropical cyclones typically develop between May and October. The season's first named storm, Pakhar, developed on March 28, while the season's last named storm, Wukong, dissipated on December 29. The season's first typhoon, Guchol, reached typhoon status on June 15, and became the first super typhoon of the year on June 17.
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 separate agencies that 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 should it be judged to have 10-minute sustained wind speeds of at least 65 km/h (40 mph) anywhere in the basin. PAGASA assigns unofficial names to tropical cyclones which move into or form as a tropical depression in their area of responsibility, located between 115°E–135°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 numerical designation with a "W" suffix.
Seasonal forecasts
During February 2012, the Pacific El Niño/Southern Oscillation Applications Climate (PEAC) Center predicted that the first half of 2012 would see below-normal tropical cyclone activity, as the 2010–2012 La Niña event would prevent the monsoon trough of low pressure from developing normally and any major activity until June. They also suggested that weather patterns would return to near-normal afterwards and that the westward displacement of systems seen in the previous two seasons would not occur. On March 20, the Hong Kong Observatory predicted that the typhoon season in Hong Kong and surrounding areas would likely start in June as a result of the La Niña event. They also predicted that between 5 and 8 systems would pass within 500 km (310 mi) of the territory and possibly impact the territory. On April 11, the Tropical Storm Risk Consortium (TSR) issued its first seasonal forecast for the year, which predicted that the basin would be about 10% below average and feature 25.5 tropical storms, 15.6 typhoons, 7.3 intense typhoons. This was followed later that month by the Shanghai Typhoon Institute (STI), who predicted that between 22 and 24 tropical storms would develop within the basin during the year before TSR tweaked its forecast in May and predicted that the season would be near-normal and feature 8.5 intense typhoons.
On May 21, the Thai Meteorological Department predicted that 1-2 tropical storms would affect Thailand during 2012, with one moving through Vietnam and impacting upper Thailand during August or September, while the other one was expected to impact southern Thailand during October or November. On June 29, Taiwan's Central Weather Bureau (CWB) noted that sea surface temperatures had been gradually increasing and that there was a 50% chance of an El Nino event developing in the Pacific Ocean during the year. They also noted that systems tended to develop further away from Taiwan, had a longer lifespan and a greater intensity during El Nino events and urged citizens and local authorities to prepare. The CWB also predicted that 23 to 26 systems would occur over the basin during the year, of which three to five were expected to impact the island nation. Within its July update, TSR significantly increased its forecast as a result of the warmer sea surface temperatures and now predicted that the basin would see activity about 10% above average with 27.4 tropical storms, 16.7 typhoons, 9.2 intense typhoons. Within its July — December seasonal climate outlook, PAGASA predicted that 7 — 10 tropical cyclones were likely to develop within or enter the Philippine area of responsibility between July and September, while 4 — 7 were predicted to occur between October and December.
Season summary
As the year opened, the Japan Meteorological Agency was monitoring a tropical depression that was located about 345 km (215 mi) to the northeast of Kuala Lumpur, Malaysia; however, the system was last noted later that day as it dissipated.
On January 13, the JMA started monitoring a tropical depression that was located within an area of moderate to strong vertical windshear about 625 km (390 mi) to the east of Kuala Lumpur in Malaysia. During that day the depression remained near stationary, before the JMA issued their final advisory on the system during the next day as the system dissipated.
The season's first named storm, Pakhar, developed on March 28 while the last named storm, Wukong, dissipated on December 29. The season became very active between mid-July and mid-August, with nine named storms formed during the period. Vicente underwent explosive intensification and made landfall over the west Pearl River Delta as a strong typhoon. Damrey developed into a typhoon in the Yellow Sea and became the most intense tropical cyclone to make landfall north of the Yangtze River since 1949. Typhoon Haikui, although centred far away from the Philippines, killed at least 89 people in the country. Typhoon Tembin affected Taiwan twice because of its cyclonic loop.
From late August to September, three very powerful typhoons, Bolaven, Sanba and Jelawat, directly hit Okinawa Island successively. In October, the remnants of Severe Tropical Storm Gaemi arrived at the Bay of Bengal and re-intensified into a deep depression before making landfall over Bangladesh. In December, Typhoon Bopha, an unusually very low-latitude but very powerful tropical cyclone, caused catastrophic damage in Mindanao in the Philippines.
Systems
Tropical Depression 01W
Early on February 17, the JMA reported that a tropical depression had developed, about 800 km (495 mi) to the southeast of Manila on the Philippine island of Luzon. During that day the depression moved westwards, before the Joint Typhoon Warning Center initiated advisories at 1500 UTC and designated the system as Tropical Depression 01W. However, six hours later the JTWC issued its final advisory as vertical windshear had started to increase, and after it had found no deep convection near the systems low level circulation centre during a reassessment of the depressions low level structure. Over the next few days the JMA continued to monitor the depression before it was last noted during February 20.
Tropical Storm Pakhar
On March 24, the JMA reported that a tropical depression had formed, about 250 mi (400 km) to the southwest of Manila, Philippines. It later weakened to a low pressure area late on the same day. Two days later, the JMA upgraded the tropical disturbance back to a tropical depression again, due to the storm reorganizing under an environment of low vertical wind shear and favorable sea surface temperatures in the South China Sea. Early on March 28, the JTWC issued a TCFA on the tropical depression. By the next day, the JMA upgraded the tropical depression to a tropical storm, and named it Pakhar. The JTWC subsequently started issuing advisories on the storm, as the storm's convection had completely wrapped around the circulation center. The JTWC later upgraded Pakhar into a tropical storm.
Early on March 30, the JTWC upgraded Pakhar to a Category 1 typhoon, as a banding eye formed; post-analysis later showed that Pakhar didn't reach typhoon intensity. Because of land interaction and colder sea surface temperatures, Pakhar weakened to a tropical storm by the next day. On April 1, Pakhar made landfall near Vũng Tàu, Vietnam. As it weakened into a tropical depression, the JMA issued their final advisory by the next day. The system was last noted over Cambodia that same day.
Although Pakhar did not affect the Philippines as a tropical cyclone, its precursor produced heavy rains across part of the nation. Flooding occurred in different parts of central and southern Luzon, and the northern Visayas region. In Basud, Camarines Norte, 128 families had to be evacuated due to flash flooding. A few landslides resulted from the rains, damaging or destroying a few homes. Throughout the affected region, five people were killed and three others were listed as missing. In Vietnam, ten people were killed and several others were injured due to flash flooding and high winds. The hardest hit area was Khánh Hòa Province where the storm made landfall. About 4,400 homes were damaged in the region by the storm and thousands of acres of rice paddy were flooded. In Ho Chi Minh City, officials reported that 600 homes and schools were destroyed. Total damage were finalized at ₫1.12 trillion (US$53.9 million). The remnants of the system brought rains to parts of Cambodia, Laos, and Thailand.
Severe Tropical Storm Sanvu
On May 18, the JTWC started to monitor an area of convection approximately 95 nmi (175 km) to the north-northwest of Chuuk. At the time, it had a developing low-level circulation center with deep convection, and was under an environment of low vertical wind shear and good divergence aloft. As it moved northwestwards, it continued to organize, prompting the JTWC to issue a TCFA two days later. The JMA subsequently upgraded the system to a tropical depression on May 21. The JTWC later followed suit, designating the depression as 03W. The system then intensified to a tropical storm late on the same day, with the JMA naming it as Sanvu early on May 22.
Sanvu then continued to intensify, with deep convection building over its center.
Late on the next day, the JTWC upgraded Sanvu to a category 1 typhoon, as an eye was seen on microwave imagery. Late on May 24, the JMA upgraded Sanvu to a severe tropical storm. Accelerating northeastward along the northwestern periphery of a subtropical ridge, the system reached its peak intensity by the next day, as its eye emerged on satellite imagery. As its western quadrant got affected by a dry air entrainment on May 26, Sanvu started to weaken as it directly passed over Iwo Jima. With strong vertical wind shear associated with a subtropical jet stream, along with rapidly cooling sea surface temperatures, the system continued to weaken. The JTWC downgraded Sanvu to a tropical storm late on the same day, as the system's low level circulation center started to become exposed. The JMA followed suit by the next day. The JTWC subsequently issued their final advisory on Sanvu, as it commenced extratropical transition. However, the JMA continued issuing advisories on Sanvu, until by the next day, when it fully transitioned into an extratropical cyclone. The remnants of the system was last noted during May 30.
As Sanvu strengthened into a tropical storm, tropical storm watches and warnings were issued for Guam, Rota, Tinian, and Saipan. It brought tropical storm force wind gusts and rainfall between 38–51 mm (1.5–2 in) to parts of Guam and the Northern Mariana Islands. However, the only damage reported was on Guam where falling tree limbs caused an estimated $20,000 of damage to power lines.
Typhoon Mawar (Ambo)
On May 29, the JTWC started to monitor a tropical disturbance that formed approximately 125 nmi (230 km) to the north of Palau. At the time, the system had a weak low-level circulation center, and was under an environment of low to moderate vertical wind shear and good divergence aloft. As the disturbance began moving northwestwards, it started to organize, with deep convection building along its developing center. Late on the next day, the system's convection became significantly organized, prompting the JTWC to issue a TCFA. By May 31, the JMA had upgraded the system to a tropical depression. The PAGASA followed suit and started issuing advisories on the system, assigning its local name Ambo. Late on the same day, the JTWC began issuing advisories on the system as it continued to consolidate its center, designating it as 04W. By the next day, Ambo intensified into a tropical storm, with the JMA assigning its international name Mawar.