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Typhoon Pongsona
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Typhoon Pongsona
Typhoon Pongsona was the last typhoon of the 2002 Pacific typhoon season, and was the second costliest United States disaster in 2002, only behind Hurricane Lili. Pongsona developed out of an area of disturbed weather on December 2, and steadily intensified to reach typhoon status on December 5. On December 8 it passed through Guam and the Northern Mariana Islands while at peak intensity, with 10-minute sustained winds of 175 km/h (110 mph). It ultimately turned to the northeast, weakened, and became extratropical on December 11.
Typhoon Pongsona produced strong wind gusts peaking at 285 km/h (175 mph), which left the entire island of Guam without power and destroyed about 1,300 houses. With strong building standards and experience from repeated typhoon strikes, there were no fatalities directly related to Pongsona, although there was one indirect death from flying glass. Damage on the island totaled over $730 million (2002 USD, $1.31 billion 2026 USD), making Pongsona among the five costliest typhoons on the island. The typhoon also caused extreme damage on Rota and elsewhere in the Northern Mariana Islands, and as a result of its impact the name was retired.
During late November, an area of convection persisted about 625 kilometers (388 miles) east-southeast of Pohnpei. Satellite imagery indicated broad cyclonic turning in the lower levels of the atmosphere, and a trough was located near the surface. The disturbance developed rainbands and gradually became better organized. By December 2, the system had an elongated low-level circulation, located to the south of the convection. At 0600 UTC that day, the Japan Meteorological Agency (JMA) classified the system as a tropical depression about 735 km (457 mi) east-northeast of Pohnpei. Shortly thereafter, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert, and at 1800 UTC on December 2 the agency classified the system as Tropical Depression 31W. Initially the depression moved to the west-northwest, and early on December 3 the JTWC classified the system as a tropical storm.
Initially, the circulation was exposed from the convection, although it was able to intensify into a tropical storm, given the name Pongsona at 1200 UTC on December 3 while located 375 km (233 mi) northeast of Pohnpei. It turned to the west on December 4, due to a ridge to the north. It slowly intensified, developing an eye feature on December 5. That day, both the JTWC and the JMA upgraded Pongsona to a typhoon about 1,150 km (710 mi) southeast of Guam.
While continuing generally to the west, the eye of Pongsona gradually became better organized. A baroclinic cyclone east of Japan weakened the ridge, which caused the typhoon to turn more to the northwest. By late on December 7, Pongsona developed a well-defined 55 km (34 mi) wide eye as it approached Guam. After the typhoon underwent rapid deepening, the JTWC estimated that Pongsona reached peak winds of 273 km/h (170 mph) 1-min sustained), making it a Super Typhoon. At 0500 UTC on December 8, the eyewall made landfall on Guam, and two hours later the northern portion of the eyewall crossed over nearby Rota. Around that time, the JMA estimated Pongsona attained a peak intensity of 175 km/h (109 mph) 10-min winds) just to the north of Guam. The typhoon turned to the north-northwest through a weakness in the subtropical ridge a short distance west of the Northern Mariana Islands. On December 9, convection began to weaken as Pongsona began interacting with a mid-latitude system to its north. Dry air became entrained in the southwestern portion of the circulation, and the circulation became exposed from the diminishing convection. As a result, both the JTWC and the JMA declared Pongsona as an extratropical cyclone on December 11 about 1,400 km (870 mi) northwest of Wake Island.
The National Weather Service in Guam issued a tropical storm watch for the Marshall Islands shortly after Pongsona developed into a tropical storm, and a day later watches were issued for Chuuk. On December 5, the service issued tropical storm warnings for parts of the Federated States of Micronesia. As Pongsona became a typhoon, the Guam National Weather Service office issued a typhoon watch for Guam, Rota, Saipan, and Tinian, which was upgraded to a typhoon warning about 23 hours prior to the onset of tropical storm-force winds; typhoon warnings were also issued for the unpopulated island of Aguigan. By one day before the typhoon moved through the Mariana Islands, JTWC predicted Pongsona to pass well east of the area. Despite a more westward track than anticipated, forecasts remained stagnant until the morning of December 8, when forecasters reluctantly predicted much greater threat to the Mariana Islands. As a result, many citizens felt they were unprepared and insufficiently warned for the typhoon.
Nine shelters throughout the Northern Mariana Islands were opened to accommodate families needing assistance. Several schools opened classrooms as evacuation centers. On Guam, ten schools were used as shelters, and on the day of impact 2,271 people were in shelters. On Rota, 159 people sought shelter, and in Saipan, 549 were in shelters by the day of impact. The Guam Memorial Hospital officials advised all pregnant women within 32 weeks of their delivery date to check in. The Guam Office of Civil Defense filed the paperwork for the Federal Emergency Management Agency to declare the island a disaster area. Governor Carl T.C. Gutierrez took similar measures to declare a state of emergency for the area. Following experience from previous typhoons, Guam newspaper Pacific Daily News underwent preparations to provide internet updates for the storm, including reinforcing the building, maintaining sufficient food supplies for the staff, and stationing two reporters elsewhere on the island; the paper was the only immediate source of information about the typhoon outside of Guam.
Early in its duration, Pongsona first affected Pohnpei as a tropical storm. There, it produced heavy rains and gusty winds, though little damage was reported. Later, it brought tropical storm force winds to Chuuk. High waves from the storm washed over and covered some atolls.
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Typhoon Pongsona
Typhoon Pongsona was the last typhoon of the 2002 Pacific typhoon season, and was the second costliest United States disaster in 2002, only behind Hurricane Lili. Pongsona developed out of an area of disturbed weather on December 2, and steadily intensified to reach typhoon status on December 5. On December 8 it passed through Guam and the Northern Mariana Islands while at peak intensity, with 10-minute sustained winds of 175 km/h (110 mph). It ultimately turned to the northeast, weakened, and became extratropical on December 11.
Typhoon Pongsona produced strong wind gusts peaking at 285 km/h (175 mph), which left the entire island of Guam without power and destroyed about 1,300 houses. With strong building standards and experience from repeated typhoon strikes, there were no fatalities directly related to Pongsona, although there was one indirect death from flying glass. Damage on the island totaled over $730 million (2002 USD, $1.31 billion 2026 USD), making Pongsona among the five costliest typhoons on the island. The typhoon also caused extreme damage on Rota and elsewhere in the Northern Mariana Islands, and as a result of its impact the name was retired.
During late November, an area of convection persisted about 625 kilometers (388 miles) east-southeast of Pohnpei. Satellite imagery indicated broad cyclonic turning in the lower levels of the atmosphere, and a trough was located near the surface. The disturbance developed rainbands and gradually became better organized. By December 2, the system had an elongated low-level circulation, located to the south of the convection. At 0600 UTC that day, the Japan Meteorological Agency (JMA) classified the system as a tropical depression about 735 km (457 mi) east-northeast of Pohnpei. Shortly thereafter, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert, and at 1800 UTC on December 2 the agency classified the system as Tropical Depression 31W. Initially the depression moved to the west-northwest, and early on December 3 the JTWC classified the system as a tropical storm.
Initially, the circulation was exposed from the convection, although it was able to intensify into a tropical storm, given the name Pongsona at 1200 UTC on December 3 while located 375 km (233 mi) northeast of Pohnpei. It turned to the west on December 4, due to a ridge to the north. It slowly intensified, developing an eye feature on December 5. That day, both the JTWC and the JMA upgraded Pongsona to a typhoon about 1,150 km (710 mi) southeast of Guam.
While continuing generally to the west, the eye of Pongsona gradually became better organized. A baroclinic cyclone east of Japan weakened the ridge, which caused the typhoon to turn more to the northwest. By late on December 7, Pongsona developed a well-defined 55 km (34 mi) wide eye as it approached Guam. After the typhoon underwent rapid deepening, the JTWC estimated that Pongsona reached peak winds of 273 km/h (170 mph) 1-min sustained), making it a Super Typhoon. At 0500 UTC on December 8, the eyewall made landfall on Guam, and two hours later the northern portion of the eyewall crossed over nearby Rota. Around that time, the JMA estimated Pongsona attained a peak intensity of 175 km/h (109 mph) 10-min winds) just to the north of Guam. The typhoon turned to the north-northwest through a weakness in the subtropical ridge a short distance west of the Northern Mariana Islands. On December 9, convection began to weaken as Pongsona began interacting with a mid-latitude system to its north. Dry air became entrained in the southwestern portion of the circulation, and the circulation became exposed from the diminishing convection. As a result, both the JTWC and the JMA declared Pongsona as an extratropical cyclone on December 11 about 1,400 km (870 mi) northwest of Wake Island.
The National Weather Service in Guam issued a tropical storm watch for the Marshall Islands shortly after Pongsona developed into a tropical storm, and a day later watches were issued for Chuuk. On December 5, the service issued tropical storm warnings for parts of the Federated States of Micronesia. As Pongsona became a typhoon, the Guam National Weather Service office issued a typhoon watch for Guam, Rota, Saipan, and Tinian, which was upgraded to a typhoon warning about 23 hours prior to the onset of tropical storm-force winds; typhoon warnings were also issued for the unpopulated island of Aguigan. By one day before the typhoon moved through the Mariana Islands, JTWC predicted Pongsona to pass well east of the area. Despite a more westward track than anticipated, forecasts remained stagnant until the morning of December 8, when forecasters reluctantly predicted much greater threat to the Mariana Islands. As a result, many citizens felt they were unprepared and insufficiently warned for the typhoon.
Nine shelters throughout the Northern Mariana Islands were opened to accommodate families needing assistance. Several schools opened classrooms as evacuation centers. On Guam, ten schools were used as shelters, and on the day of impact 2,271 people were in shelters. On Rota, 159 people sought shelter, and in Saipan, 549 were in shelters by the day of impact. The Guam Memorial Hospital officials advised all pregnant women within 32 weeks of their delivery date to check in. The Guam Office of Civil Defense filed the paperwork for the Federal Emergency Management Agency to declare the island a disaster area. Governor Carl T.C. Gutierrez took similar measures to declare a state of emergency for the area. Following experience from previous typhoons, Guam newspaper Pacific Daily News underwent preparations to provide internet updates for the storm, including reinforcing the building, maintaining sufficient food supplies for the staff, and stationing two reporters elsewhere on the island; the paper was the only immediate source of information about the typhoon outside of Guam.
Early in its duration, Pongsona first affected Pohnpei as a tropical storm. There, it produced heavy rains and gusty winds, though little damage was reported. Later, it brought tropical storm force winds to Chuuk. High waves from the storm washed over and covered some atolls.
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