|Typhoon (JMA scale)|
|Category 4 (Saffir–Simpson scale)|
|Formed||August 23, 1992|
|Dissipated||September 9, 1992|
|Highest winds||10-minute sustained: 185 km/h (115 mph)
1-minute sustained: 240 km/h (150 mph)
|Lowest pressure||920 mbar (hPa); 27.17 inHg|
|Damage||$457 million (1992 USD)|
|Areas affected||Guam, Philippines, Taiwan, China|
|Part of the 1992 Pacific typhoon season|
Typhoon Omar, known in the Philippines as Typhoon Lusing, was the 15th tropical depression, the 15th named storm, and the 9th typhoon of the 1992 Pacific typhoon season. It caused 2 deaths in Taiwan and $457 million (1992 USD, $618.9 million 2005 USD) in damage.
The origin of Typhoon Omar were from a tropical disturbance exhibiting persistent thunderstorm activity that was first noted east of Kiribati on August 20. During this primitive phase, the western Pacific basin saw the dissipation of two tropical cyclones and the extratropical transition of two others, forcing the Pacific monsoon trough to realign itself in a more climatologically normal fashion and thus provide favorable atmospheric conditions over the disturbance. With these conditions set in place, the system intensified, and the Japan Meteorological Agency (JMA) to have reached tropical depression intensity at 1800 UTC on August 23.[nb 1] The Joint Typhoon Warning Center (JTWC) analyzed a slower pace of strengthening,[nb 2] issuing a Tropical Cyclone Formation Alert at 2100 UTC before proceeding with advisories on Tropical Depression 15W on August 24, 370 km (230 mi) east-southeast of Guam. Tracking generally westward, the JTWC upgraded the depression tropical storm strength, with the JMA indicating such a change the day after.
Although it was fostered in conditions suitable for tropical cyclogenesis, Omar began to slow as it tracked westward, causing outflow from nearby Tropical Storm Polly to shear the system and slowing intensification despite an otherwise conducive environment. Although the wind shear came close to forcing the dissipation of Omar, the storm proceeded westward on August 27 and resumed strengthening shortly thereafter. At 0600 UTC that day, the JTWC designated the system as a typhoon. Omar began to rapidly intensify on August 28, quickly developing an eye. That day, the typhoon made landfall on Guam with maximum sustained winds of roughly 140 km/h (85 mph). At 1800 UTC on August 29, Omar reached its peak intensity with sustained winds estimated at 185 km/h (100 mph) and a minimum barometric pressure of 920 mbar (hPa; 27.17 inHg); this intensity was maintained for 24 hours before a steady weakening phase began. Two days later, the storm came close enough to the Philippines to warrant monitoring activities from the Philippine Atmospheric, Geophysical and Astronomical Services Administration, who assigned the storm with the local name Lusing. At 1500 UTC on September 3, the JMA considered Omar to have weakened below typhoon intensity. Still assuming a generally westward heading, the storm made landfall on the east coast of Taiwan the following day before crossing into the Taiwan Strait and making a final landfall near Xiamen, China on September 5. Over land, Omar quickly degenerated into a tropical depression before dissipating entirely on September 9.
Preparations and impact
Posing a threat to United States Navy interests in Guam, fixed-wing aircraft and helicopters were moved into hangars on the island or transported to Japan or the Philippines, away from the expected path of the storm. Ships faced the same precautionary measures as they were either evacuated to seas southwest of Guam or secured in harbor. United States civil defense ordered the closure of schools for the duration of Omar's passage of Guam.
Omar was the most damaging Guam typhoon since Typhoon Pamela in 1976. The effects of Omar were felt on all parts of the island. Storm surge from the tropical cyclone occurred coincident with the August spring tide, and although it was lower than initially forecast, still ran up the coast by 3 m (10 ft) in some areas of the northern Guam coast. The USS Niagara Falls (AFS-3) and USS White Plains (AFS-4)—both naval supply ships—went aground due to the rough seas and strong winds. These winds fully disabled power, transportation, and communication systems, leading to the failure of water pumping systems. Over 2,158 homes were damaged or destroyed, displacing nearly 3,000 people. Rainfall from Omar was also exceptionally intense, peaking at 460 mm (18 in) in Taguac. The damage inflicted on the island totaled US$457 million, and although no deaths were reported, there were over 200 injuries necessitating emergency treatment.
Omar's passage in Taiwan led to torrential rains, though not as severe as in Guam. Two people were killed from the flooding, with 12 injuries and major power outages also experienced. Damage totals are not available.
Immediately following the landfall of Omar in Guam, then-U.S. President George H. W. Bush declared the island a federal disaster area. Due to the destruction in Guam, the name Omar was retired and was replaced with Oscar.
- The Japan Meteorological Agency is the official Regional Specialized Meteorological Center for the western Pacific Ocean.
- The Joint Typhoon Warning Center is a joint United States Navy – United States Air Force task force that issues tropical cyclone warnings for the western Pacific Ocean and other regions.
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