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The February 2013 nor'easter (also known unofficially as Winter Storm Nemo〔〔〔〔〔 or the Blizzard of 2013) was a powerful winter storm that developed from the combination of two areas of low pressure, primarily affecting the Northeastern United States and parts of Canada, causing heavy snowfall and hurricane-force winds. The storm crossed the Atlantic Ocean, affecting Ireland and the United Kingdom.〔(Warning as snowstorm Nemo heads for Britain | UK | News | Daily Express )〕 The nor'easter's effects in the United States received a Category 3 rank on the Northeast Snowfall Impact Scale, classifying it as a "Major" Winter Storm. The first low-pressure system, originating from the Northern Plains of the United States, produced moderate amounts of snow across the Great Lakes region of the U.S. and Canada. The second low, originating across the state of Texas, produced heavy rains and flooding across much of the Southeast and Mid-Atlantic parts of the U.S. As the two systems merged off the Northeast coast on February 8, 2013, they produced heavy snowfall over a large region from North Jersey and inland from New York City through eastern New England up to coastal Maine and inland to Ontario. Total snowfall in Boston, Massachusetts, reached , the fifth-highest total ever recorded in the city.〔 New York City officially recorded of snow at Central Park, and Portland, Maine, set a record of . Hamden, Connecticut recorded the highest snowfall of the storm at . Many surrounding cities picked up at least . In addition to the significant snowfall totals, hurricane-force wind gusts were recorded, reaching in Nova Scotia, at Mount Desert Rock, Maine, and off the coast of Cuttyhunk, Massachusetts.〔〔(Mount Desert Rock Continuous Winds Data )〕〔(Buzzards Bay, MA Continuous Winds Data )〕 Boston experienced a storm surge of , its fourth-highest. The storm affected Atlantic Canada after hitting the Northeastern United States. Watches and warnings were issued in preparation for the storm, and state governors declared states of emergency in all states in New England and in New York. Flights at many major airports across the region were canceled, and travel bans were put into place on February 8 in several states. Hundreds ended up stranded on Long Island late on February 8 as a result of the rapidly accumulating snowfall. A combination of strong winds and heavy, wet snow left 700,000 customers without electricity at the height of the storm.〔(Blizzard hammers U.S. Northeast, five dead, 700,000 lose power )〕 At least eighteen deaths were attributed to the storm.〔(【引用サイトリンク】url=http://northport.patch.com/articles/three-northport-men-die-while-removing-snow )〕〔〔〔〔〔(Major snowstorm wallops Ontario - Canada - Canoe.ca )〕 ==Meteorological history== Atmospheric conditions leading up to the formation of the February 2013 nor'easter were rather anomalous and were conducive for cyclogenesis. Such conditions included the presence of a ridge over the North Atlantic and the strengthening of a trough in California. The impactful nature of the eventual winter storm event was first predicted in National Centers for Environmental Prediction (NCEP) and Hydrometeorological Prediction Center (HPC) forecasts at 1200 UTC on February 6, when the accumulation of at least of snow in the ensuing hours was considered a moderate probability in parts of Wisconsin and Michigan. Fueled by energy originating from the Gulf of Alaska and carried by the polar jet stream, a low-pressure area formed as anticipated in Montana at 1200 UTC the next day.〔 The cyclone tracked in a general east-northeastward direction throughout the day, reaching central Indiana by early on February 8. As the low-pressure system over the United States Midwest developed, energy associated with the subtropical jet over the Mexican plateau tracked into the Gulf of Mexico, resulting in the formation of another low-pressure area just off the Texas coast on February 7.〔 Tracking eastward, the system produced isolated severe weather across the United States Gulf Coast. Nearing noon that day, the cyclone moved into the Florida Panhandle. By February 8, the low-pressure system had moved into Georgia. Both the system in the Gulf of Mexico and the system in the Midwestern United States were supported by the same shortwave trough. Due to blocking steering patterns, both storms began to gravitate towards the Eastern Seaboard.〔 The HPC began issuing periodic storm summary bulletins on the two low-pressure areas at 0300 UTC on February 8. Their forecasts suggested that the system associated with the subtropical jet stream would rapidly intensify near the United States East Coast, later absorbing the system associated with the polar jet stream. A few hours later, the southern disturbance began a phase of barometric deepening as it tracked northeastward off the Outer Banks, while the northern system maintained an easterly course into northwestern Ohio. Beginning at 0000 UTC on February 9, the two systems began an extensive merging process, with the strengthening cyclone originating from the subtropics absorbing energy from the cyclone originating from the polar jet stream.〔 This resulted in the cyclone off the United States East Coast to continue intensifying while the initial system to the northwest gradually diffused over the Mid-Atlantic states. Throughout the day the resulting system continued to track to the northeast, bringing along with it a large swath of snowfall that tracked across New England and into Canada. By 1200 UTC, the extratropical cyclone had strengthened enough to classify it as a bomb. At 2100 UTC on February 9, the extratropical cyclone reached its peak intensity with a minimum barometric pressure of 968 mbar (hPa; 28.59 inHg) while located roughly off the coast of Massachusetts. After reaching peak intensity the system began to steadily weaken and depart the coast of New England, tracking near Nova Scotia early on February 10, upon which the HPC issued their final storm summary bulletin. Despite the discontinuance of bulletins, the extr-tropical cyclone continued to persist and assumed an easterly course. By February 13, the storm system had tracked just south of Iceland, bringing a cold and warm front into the British Isles. The system then began to curve northward through the Norwegian Sea over the next few days, before it was absorbed by a larger system on February 18. 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「February 2013 nor'easter」の詳細全文を読む スポンサード リンク
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