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Hurricane Ernesto was a Category 2 hurricane and damaging tropical cyclone that affected several Caribbean Islands and areas of Central America during August 2012. The fifth named storm and second hurricane of the 2012 Atlantic hurricane season, Ernesto originated from a tropical wave that emerged off the west coast of Africa in late July. Moving westward, the system developed into a tropical depression in the central Atlantic, and further into a tropical storm prior to entering the Caribbean Sea. The system encountered high wind shear south of Jamaica but subsequently reached its peak intensity as a Category 2 hurricane as it made landfall on the Yucatán Peninsula. Ernesto briefly emerged in the Bay of Campeche as a strong tropical storm before dissipating over the mountainous terrain of Mexico. The remnant circulation emerged in the eastern Pacific basin, contributing to the formation of Tropical Storm Hector. Following the formation of the system, tropical storm watches and warnings were issued for the Windward Islands. Hurricane watches and warnings were extended for nearby Caribbean Islands in the days following as Ernesto trekked across the central Caribbean Sea. Evacuations were performed in low-lying areas on the Yucatán Peninsula and cruise ship departures were cancelled. ==Meteorological history== On July 27, the precursor to Ernesto moved off the west coast of Africa as a tropical wave. At the time, the wave was associated with a disorganized area of convection. On July 29, a broad low pressure area developed in association with the tropical wave. The National Hurricane Center (NHC) first monitored the tropical wave in its tropical weather outlook on July 30, noting that the system had an accompanying low pressure area and was showing signs of development. The convection slowly organized due to generally favorable environmental conditions. After the circulation became better defined, the NHC initiated advisories on Tropical Depression Five at 2100 UTC on August 1. At the time, the depression was located about 810 mi (1305 km) east of the Lesser Antilles, moving west-northwestward due to an anticyclone to its north. In the 12 hours after its formation, the system's convection became disorganized due to westerly wind shear and dry air, and the NHC remarked the potential for degeneration into a tropical wave. However, the depression's rainbands began to strengthen and become more organized.〔 A Hurricane Hunters flight on August 2 observed tropical storm force winds, and accordingly the NHC upgraded the depression to Tropical Storm Ernesto at 2100 UTC. After becoming a tropical storm, Ernesto initially had difficulty maintaining convection near the center, and its rapid westward movement prevented significant organization. At around 1200 UTC on August 3, the storm moved over or very near Saint Lucia, and radar imagery observed a well-defined circulation moving by the island. Wind shear gradually decreased over the storm, allowing for outflow to increase in its western portion. There were disparities among tropical cyclone forecast models over the future of Ernesto; some anticipated significant intensification due to warm waters and low shear, whereas others forecast the storm to remain a minimal storm or even weaken. Although the satellite appearance was well-organized, a Hurricane Hunters flight on August 4 observed a disorganized structure, and early the next day the circulation became exposed to the northwest of the convection; the weakening was possibly due to dry air and some mid-level shear, despite otherwise favorable conditions. On August 5, the storm passed south of Jamaica.〔 Early on August 6, convection redeveloped over the center after Ernesto slowed its westward movement, and decreasing wind shear allowed for restrengthening. Late on August 7, Ernesto intensified into a hurricane to the north of Honduras. While approaching the Yucatán Peninsula, Ernesto quickly intensified, developing a well-defined eye. Early on August 8, the hurricane moved over Banco Chinchorro offshore extreme eastern Mexico as a strong Category 1 storm, then strengthened further into a Category 2 hurricane before making its mainland landfall on Mahahual, Quintana Roo, at around 10:15 p.m. CDT (0315 UTC), with winds of 100 mph (160 km/h). The 85-kt estimated landfall and peak intensity of Ernesto is based on a blend of Dvorak intensity estimates of 77 and 90 kt from 0000 UTC and 0300 UTC 8 August 2012, respectively; the 90-kt Dvorak estimate at landfall was performed by TAFB during the post-storm analysis. The improved structure and continued intensification of Ernesto through landfall is also supported by two minimum pressure observations in Mexico. An automated observing site on the Banco Chinchorro Islands reported a minimum pressure of 979.4 mb (Table 2) at 0100 UTC 8 August as the center passed over the area. This was 5 mb lower than the minimum pressure reported by reconnaissance aircraft 8 h earlier. A storm chaser located inland near Buena Vista, Mexico, reported a minimum pressure of 975.0 mb (Table 2) at 0534 UTC while still experiencing strong winds. Based on these data, the estimated minimum pressure at landfall is 973 mb. Ernesto later weakened to tropical storm status after its convection weakened over land. It reemerged over the Bay of Campeche, and intensified into a strong tropical storm. The system moved inland across the Isthmus of Tehuantepec on the afternoon of August 9, and into southern Mexico before dissipating as a tropical cyclone on August 10. The remnants later contributed to the development of Tropical Storm Hector in the Eastern Pacific on August 11. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Hurricane Ernesto (2012)」の詳細全文を読む スポンサード リンク
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