|
The December 1960 nor'easter was a significant early-season winter storm that impacted the Mid-Atlantic and New England regions of the United States. Moderate to heavy snowfall fell from West Virginia to eastern Maine, amounting to 10 in (25 cm) or more in parts of 13 states and peaking at 21.4 in (54.4 cm) at Newark, New Jersey. The storm was accompanied by strong winds, gusting to over 90 mph (145 km/h) in coastal New England, and left in its wake a dangerously cold air mass. The storm originated in a weak low pressure area which formed over the western Gulf of Mexico on December 10. A secondary low developed over South Carolina on the next day, supported by the merger of two troughs aloft. Sliding southeast of New England, the new storm explosively deepened to become a full-fledged nor'easter, with a minimum central air pressure of 966 mbar. It began to weaken over the Canadian Maritimes. Widespread blizzard conditions wrought havoc on transportation; streets and highways throughout the hardest-hit areas were clogged with stalled and abandoned vehicles, and multiple major airports were forced to close. Many schools and businesses were closed, some for days after the storm departed. The New York Stock Exchange opened an hour late on December 12, marking its first delayed opening in over 25 years. Extensive drifting of snow left communities isolated and unable to receive deliveries of food and heating fuel. Overall, the storm and subsequent cold snap were blamed for at least 286 deaths across a wide area, but primarily in Pennsylvania, New Jersey, New York, and the New England states. The fatalities resulted from a multitude of tragedies, including automobile and maritime accidents, storm-related fires, carbon monoxide poisoning, over-exertion, and exposure to cold. ==Meteorological history== The nor'easter occurred during a positive phase of the North Atlantic oscillation (NAO),〔 though negative NAO values are typically considered optimal for snowstorms in the northeastern United States.〔Kocin and Uccellini, pp. 34–35〕 It was the first of three severe storms during the 1960–1961 winter season.〔Kocin and Uccellini, p. 391〕 It originated in an area of low pressure that developed over the western Gulf of Mexico on December 10,〔 downstream from an upper-level cyclone.〔Kocin and Uccellini, p. 397〕 The surface low tracked northward to Oklahoma before turning eastward as it gradually intensified.〔 Simultaneously, a shortwave trough swung southeastward around the periphery of a large vortex over central and eastern Canada. As the upper low opened up into a negatively tilted trough and began to interact with the northern wave, a secondary surface cyclone developed along a frontal boundary over South Carolina late on December 11. Almost immediately thereafter, the original low dissipated over West Virginia. Heading toward the northeast, the incipient storm emerged into the Atlantic Ocean near Cape Hatteras, North Carolina, at 00:00 UTC on December 12.〔 With strong upper-level support—including extensive positive vorticity advection and dual divergent jet streak regions—the storm explosively intensified into a powerful nor'easter.〔〔 From 00:00 to 12:00 UTC on December 12, the system deepened by 27 mbar while moving to a point south of Nantucket.〔 By contrast, the widely-accepted criterion for "bombogenesis" is a 24-mbar central pressure drop in 24 hours. Its core pressure ultimately fell to 966 mbar by 00:00 UTC the next day, while located off the coast of southwestern Nova Scotia.〔〔Kocin and Uccellini, p. 398〕 A rapidly tightening pressure gradient north of the cyclone generated strong winds throughout coastal New England.〔 The storm started to slowly weaken as it moved over the Canadian Maritimes on December 13 and 14. 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「December 1960 nor'easter」の詳細全文を読む スポンサード リンク
|