Typhoon Pongsona
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| Typhoon (JMA) | |||
|---|---|---|---|
| Category 4 super typhoon (SSHS) | |||
 Typhoon Pongsona striking Guam. |
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| Formed | December 2, 2002 | ||
| Dissipated | December 11, 2002 | ||
| Highest winds |
|
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| Lowest pressure | 940 mbar (hPa) | ||
| Damage | $700 million (2003 USD) | ||
| Fatalities | 3 direct or indirect | ||
| Areas affected |
Guam, Northern Marianas Islands | ||
| Part of the 2002 Pacific typhoon season |
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Typhoon Pongsona (international designation: 0226, JTWC designation: 31W) was the last typhoon of the 2002 Pacific typhoon season that struck the Pacific island of Guam. The name "Pongsona" was contributed by North Korea and is the Korean name for the garden basalm.[1] 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 Marianas Islands while near its peak intensity. It ultimately turned to the northeast, weakened, and became extratropical on December 11 due to dry air.
Because Pongsona occurred in the Japan Meteorological Agency area of responsiblity, this article uses 10-minute wind speeds.[2]
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[edit] Storm History
An area of convection persisted 390 miles (625 km) east-southeast of Pohnpei on November 30. With low vertical shear and weak to moderate diffluence, the system steadily organized as it drifted north-northeastward. Deep convection developed near a low level circulation,[3] and the Japan Meteorological Agency upgraded the system to a tropical depression on December 2 while located 450 miles (735 km) east-northeast of Pohnpei. The depression initially remained weak as it moved west-northwestward, but organized enough to be classified a tropical storm on December 3 while located 230 miles (375 km) northeast of Pohnpei.[4]
Pongsona continued to slowly intensify as it moved westward, and became a strong tropical storm with winds of 65 mph on December 4 while 80 miles (130 km) north of Pohnpei.[4] The mid-level ridge which had resulted in the storm's westward motion weakened due to a shortwave trough, causing Pongsona to turn more to the northwest. Banding features increased, while a warm spot developed in the center of the convection.[3] The storm continued to organize, and Pongsona intensified into a typhoon on December 5 while located 715 miles (1150 km) southeast of Guam.[4]
Pongsona continued to strengthen as it moved to the northwest, and reached the equivalent of a Category 2 hurricane by December 8. Shortly thereafter, the 32 mile wide eye passed directly over Guam with winds of 100 mph (160 km/h), and six hours later, Pongsona reached a peak intensity of 105 mph (165 km/h). After maintaining that intensity for 36 hours while passing a short distance west of the Northern Marianas Islands, the typhoon turned to the northeast and weakened due to dry air and a mid-latitude low pressure system. By December 11, Pongsona weakened into a tropical storm, and six hours later, the storm became extratropical 860 miles northwest of Wake Island. The extratropical storm lost its identity on December 12.[3]
[edit] Differences between warning centers
The Japan Meteorological Agency uses 10-minute sustained winds, while the Joint Typhoon Warning Center uses 1-minute sustained winds. The conversion factor between the two is 1.14.[2] JMA's peak intensity for Pongsona was 105 mph 10-minute sustained, or 120 mph 1-minute sustained. The JTWC's peak intensity for Pongsona was 150 mph 1-minute sustained, or 130 mph 10-minute sustained. The National Meteorological Center of China's peak intensity for Pongsona was 115 mph 10-minute sustained, or 135 mph 1-minute sustained.[3]
[edit] Preparations
The Guam National Weather Service 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 all of the Federal States of Micronesia.[5] As Pongsona became a typhoon, the Guam National Weather Service 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 typhoon-force winds. Typhoon warnings were also issued for the unpopulated island of Agrihan. By one day prior to the typhoon moving through the Mariana Islands, local weather offices predicted Pongsona to pass well east of the area. Despite a more westward motion than anticipated, forecasts remained stagnant until the morning of December 8, when two lead 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.[5]
Nine shelters throughout the Northern Mariana Islands were opened to accommodate families needing assistance. Several schools opened classrooms as evacuation centers, as well.[6] On Guam, ten schools were used as shelters,[7] and on the day of impact 2,271 people were in shelters. 150 people on Rota sought shelter, and in Saipan 549 people were in shelters by the day of impact.[8] The Guam Memorial Hospital officials advised all pregnant mothers within 32 weeks of their delivery date to check in. The Guam office of civil defense filed the necessary paperwork for Federal Emergency Management Agency to declare the island as a disaster area. Governor Carl T.C. Gutierrez also took similar measures to declare a state of emergency for the area.[7] Following the experience from previous typhoons, the Guam newspaper Pacific Daily News underwent great preparedness actions, including installing storm shutters, reinforcing the building, using three generators with a fuel tank installed after a previous typhoon, water supplies, and sufficient food supplies for the staff. The staff also stationed two reporters elsewhere on the island to provide information for later updates as well as the paper's website.[9]
[edit] Impact
Pongsona struck Guam with category 4 sustained winds of 144 mph (232 km/h), gusts to 173 mph (278 km/h), and a pressure of 934 mb (27.61 in). Preliminary damage figures for the island were $700 million (2003 USD). Pongsona was the third strongest typhoon in history to strike Guam, and among the five costliest. There were 3 fatalities that couldn't be classified as direct or indirect, over 200 injuries, and 2,000 people left homeless.
The 40 mile (64 km) wide eye passed over the northern half of the island exposing the most populated areas to the eyewall with typhoon-force winds for up to five hours. Anderson Air Force Base was in the eye for two hours. Up to 26 inches (66 cm) of rain was reported.
[edit] Aftermath
Guam received a federal disaster declaration from President Bush and FEMA. Guam is frequently struck by typhoons, as was shown by the fact that the eyes of six typhoons had passed over Guam in the preceding ten years, so the population was experienced, the authorities well prepared, and building codes are very strict. In addition to typical damage sustained as the result of a major storm--downed power lines, no power/water, and storm debris, Guam experienced a temporary gas shortage afterwards due to a large gas storage tank being set ablaze by the high winds and destroyed during the storm. The tank burned for a couple of days afterwards with the blaze itself being visible from the air.
Due to the damage resulted from the storm, the name Pongsona was retired and replaced with the name Noul.
[edit] See also
[edit] External links
- NWS Service Assessment
- FEMA Federal Disaster Declaration report
- Earth Observatory summary with satellite imagery (NASA)
- TRMM satellite summary (NASA)
- NASA Visualization page
- BBC report
[edit] References
- ^ Gary Padgett (February 24). Monthly Global Tropical Cyclone Summary. Retrieved on 2006-08-14.
- ^ a b Joint Typhoon Warning Center (2005). Frequently Asked Questions.
- ^ a b c d Gary Padgett (2003). Tropical Cyclone Summary for December 2002. Retrieved on 2006-07-19.
- ^ a b c Japan Meteorological Agency (2002). 2003 Western Pacific Tropical Summary. Retrieved on 2006-07-19.
- ^ a b John J. Kelly Jr. (2003). Super Typhoon Pongsona Service Assessment. United States Departent of Commerce. Retrieved on 2006-10-07.
- ^ Saipan Tribune. "Residents told: Prepare for typhoon". Retrieved on 2006-10-07.
- ^ a b Sabina Salas (2002). Brace for impact:Pongsona to hit Guam and Rota this afternoon. KUAM. Retrieved on 2006-10-07.
- ^ National Climatic Data Center (2003). Event Report for Typhoon Pongsona. Retrieved on 2006-10-10.
- ^ FEMA (2003). When the Media is a Disaster Victim: How one small Paper kept the world informed. Retrieved on 2006-10-07.
