The 2007 Pacific typhoon season was a below average season which featured 24 named storms, fourteen typhoons, and five 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 2007, though most tropical cyclones typically develop between May and November. The season's first named typhoon, Kong-rey, developed on March 30, while the season's last named storm, Mitag, dissipated on November 27. The season's second typhoon, Yutu, reached typhoon status on May 18, and became the first super typhoon of the year on the next day.
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
City University of Hong Kong
Since the 2000 typhoon season, the Laboratory for Atmospheric Research (LAR), of the City University of Hong Kong have issued forecasts of activity for each upcoming typhoon season. Forecasts were released in April and June predicting how many tropical cyclones, tropical storms, and typhoons there will be during the season. During the season, the LAR is predicting a below average season with fewer than usual tropical cyclones. In its April forecast, the LAR predicted that 28 tropical cyclones, 25 tropical storms, and 14 typhoons before in its June forecast predicting 27 tropical cyclones, 24 tropical storms and 14 typhoons.
Tropical Storm Risk Consortium
Since the 2000 typhoon season, the Tropical Storm Risk Consortium (TSR) of the University College of London have issued forecasts of activity for each upcoming typhoon season. During 2007, forecasts were released in March, May, June, July and August predicting how many tropical cyclones, tropical storms, typhoons and intense typhoons there will be during a season. In its March forecast, TSR predicted that the season would be about 15% below average with 24 tropical storms, 15 typhoons and 7 intense typhoons. In its May forecast, TSR predicted that the season would now be near normal with 27 tropical storms, 17 typhoons and 8 intense typhoons forming during the season. Within their June July and August forecasts, TSR forecasted the season would be near normal with 27 tropical storms and 17 typhoons forming.
National meteorological service predictions
The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), reported on January 27, 2007, that they were expecting 15–19 tropical cyclones to move through their area of responsibility, during the upcoming typhoon season. They also predicted that due to the weak El Niño event that was occurring the first tropical cyclone wouldn't move through their area of responsibility until May.
Seasonal summary
According to PAGASA, the Philippines had its second quietest season with 14 named storms since the 1998 season, with the 2002 and 2010 being the most quiet season.
Systems
Typhoon Kong-rey
On March 26, the JTWC identified a broad area of low pressure in the Western North Pacific. It moved west-northwestward over the next few days, slowly gaining organization. According to the Japan Meteorological Agency, it became a tropical depression on March 30. The next day, the Joint Typhoon Warning Center issued a Tropical Cyclone Formation Alert due to an increased consolidation of the low-level circulation of the system. The JTWC issued its first warning on Tropical Depression 01W late that evening local time. As it continued to strengthen, the JTWC upgraded it to a tropical storm, the first of the season. The JMA followed suit, and named the system Kong-rey. The name was submitted by Cambodia, and refers to a character in a Khmer legend, which is also the name of a mountain.
Kong-rey continued to organize and intensified into a severe tropical storm early the next morning local time. The JTWC then upgraded it to a typhoon on April 2. As the system took a more poleward track towards the Northern Mariana Islands, the National Weather Service office in Guam noted that damaging winds were now not expected on the island. Elsewhere in the Marianas, preparations were made and flights were cancelled in anticipation of the typhoon. Kong-rey passed through the islands in the early hours of the morning on April 3 local time. The JMA upgraded Kong-rey to a typhoon later that afternoon, as it developed an eye. It strengthened slightly further before encountering wind shear and colder sea surface temperatures and was downgraded back to a severe tropical storm on April 4. As Kong-rey accelerated towards the northeast, it began undergoing extratropical transition early on April 5 and the JTWC issued its final warning.
The JMA issued its final warning on the morning of April 6 after it had completed extratropical transition. No casualties or major damage was reported.
Typhoon Yutu (Amang)
On May 15, a significant consolidation of organisation in a tropical disturbance located south-southeast of Guam led to Dvorak technique numbers equating to a windspeed of 45 knots (83 km/h) from the Air Force Weather Agency. Later that day, the Japan Meteorological Agency designated the system a tropical depression, and the Joint Typhoon Warning Center issued a Tropical Cyclone Formation Alert. The next day, the JMA began issuing full advisories on the tropical depression. It developed slowly, resulting in a reissuance of the TCFA later that day. In this second TCFA, the JTWC noted "an increasingly well-defined" low-level circulation centre. The JTWC upgraded the system to Tropical Depression 02W at 1200 UTC, based on satellite intensity estimates and QuikSCAT. The JMA designated 02W as Tropical Storm Yutu early on May 17, as the system strengthened further. The name 'Yutu' was contributed by China, and refers to a rabbit in a Chinese fable. The JTWC followed suit 3 hours later, upgrading the system to Tropical Storm 02W as it moved quickly westwards, heading for Yap. Tropical storm warnings and watches were put in place for most of the Yap State, but were later cancelled after Yutu passed through quickly.
It then took a northwesterly turn, entered the PAGASA area of responsibility on May 18 as it reached severe tropical storm strength, and was named "Amang". Later that day, the JTWC upgraded it to a typhoon, and identified a "distinct eye feature", and the JMA upgraded the severe tropical storm to a typhoon at 1800 UTC as it continued to intensify. It began to recurve towards Iwo Jima, undergoing rapid intensification, with "enhanced poleward outflow and low vertical wind shear". It reached its peak on the evening of May 20, as a strong Category 4-equivalent typhoon, just short of becoming a super typhoon. Despite moving into cooler waters, its strong poleward outflow helped it to maintain a high intensity, while carrying a 20 nautical mile-wide eye, on the early morning of May 21. It then began to gradually weaken, passing over Okinotorishima and near Iwo Jima that day as it sped off to the northeast. Maximum winds on Iwo Jima occurred around 1500 UTC that day, with 66 knots (122 km/h; 76 mph) sustained gusting to 104 knots (193 km/h; 120 mph), when a minimum central pressure of 976 hPa was recorded. It then started extratropical transition, and the JTWC issued its final warning on the morning of May 22. The JMA issued its last advisory after extratropical transition completed a day later.
Tropical Storm Toraji
An area of disturbed weather formed in the South China Sea on July 2 and gradually consolidated over the next two days as it moved west-northwestward. A Tropical Cyclone Formation Alert was issued by the Joint Typhoon Warning Center on the morning of July 4, and later that day the disturbance was upgraded straight to a tropical storm just south-east of Hainan Island. It made landfall on the island shortly after. China claimed that a tropical depression formed in the morning on July 2, made landfall in Hainan later that afternoon with maximum sustained winds of 15 metres per second (54 km/h; 34 mph) and deepened to 988hPa before making its second landfall. The Japan Meteorological Agency upgraded the tropical depression to Tropical Storm Toraji on the morning of July 5 while it was in the Gulf of Tonkin, after the centre of the storm had emerged back over water. The name Toraji was contributed by North Korea and refers to the broad bellflower (platycodi radix). Toraji made landfall in Vietnam around 1200 UTC later that evening, having not strengthened much while over the Gulf of Tonkin. The JMA never analysed the storm beyond 994 hPa and minimal tropical storm strength. The JTWC issued its last advisory after landfall, and the JMA followed suit shortly after.
Throughout Guangxi Province, an estimated 1.11 million people were affected by Toraji. Heavy rains produced by the storm inundated an estimated 7,500 hectares of farmland and damaged 1,300 homes. The flooding forced about 147,000 people to evacuate to safer locations. Damages from the storm amounted to ¥73.6 million (US$9.7 million). Several small fishing boats sank off the coast of Vietnam, the fate of the crews are unknown. Several other offshore incidents occurred, including a few collisions resulting in a minor oil spill. Throughout northern areas of the country, an average of 155 mm (6.1 in) of rain fell, leading to flooding and landslides. At least 27 homes were damaged and 13 others were destroyed by the storm, leaving hundreds of millions of Vietnamese đồng in losses. A power station at a military base was damaged during the storm, leaving roughly 40 million (VND; US$2,240).
Typhoon Man-yi (Bebeng)
The Joint Typhoon Warning Center began to track an area of disturbed weather just north of the equator on July 4. The circulation centre and surrounding convection started to take shape, although the system was in a "marginal upper-level environment" with moderate vertical wind shear. Surface pressure drops of less than 0.5 mb (hPa) were observed on July 6, as the system moved westward. Early on July 7, the Japan Meteorological Agency (JMA) listed the system as a weak tropical depression. Hours later, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert, as the system consolidated further with "deep convective banding" and improving upper-level conditions. The JTWC issued its first warning on Tropical Depression 04W later that day, and forecast a gradual intensification, as weak to moderate wind shear and weak poleward outflow balanced the effect of high ocean heat content. The JMA began issuing full tropical cyclone advisories on the tropical depression at the same time. As the depression gained more organisation, it was upgraded to a tropical storm that night by the JTWC. The JMA finally upgraded it to a tropical storm later that evening as the large system consolidated, naming it Man-yi. The name "Man-yi" was contributed by Hong Kong, and is the Chinese name of a strait turned reservoir (the High Island Reservoir). Man-yi continued to organize and became a severe tropical storm on July 9, when downed electricity lines caused widespread power outages on Guam. Tropical storm warnings and typhoon watches were put in place for most of Yap State at some point during the storm. Strong waves from the typhoon capsized a ship 375 miles (604 km) to the northwest of Guam, killing three and leaving six missing. The JTWC upgraded the storm to a typhoon on the afternoon of July 10, based on Dvorak technique satellite intensity estimates of 65 knots (120 km/h) by both the JMA and the JTWC. Early the next day, the system entered the Philippine Area of Responsibility and was named "Bebeng" by PAGASA. At the same time, the JMA upgraded Man-yi to a typhoon.