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The 1985 Election Day floods (also known as the Killer Floods of 1985 in West Virginia)〔 produced the costliest floods in both West Virginia and Virginia in November 1985. The event occurred after Hurricane Juan, a tropical cyclone in the 1985 Atlantic hurricane season, meandered near the coast of Louisiana before striking just west of Pensacola, Florida late on October 31. Juan moved northward into Canada, but spawned another system that spread moderate rainfall across the Mid-Atlantic States, wetting soils. On November 3, a low pressure area developed south of Florida and moved northeastward along a cold front, bringing a plume of moisture influenced by Juan's previous track. The storm moved through the southeastern United States, stalling on November 5 west of Washington, D.C. before turning out to sea the next day. The event was known as the Election Day floods due to its concurrence with elections in Virginia. Damage was heaviest in Virginia and West Virginia. In the former state, the rainfall peaked at just northeast of Montebello. The rains increased levels along many rivers to record heights across Virginia, including the James River which crested at at a station called Holcomb Rock, the highest level in the state. In Roanoke, the Roanoke River rose in ten hours to a peak of , considered a 1 in 200 year event. In the city, many residents had to be rescued after they were trapped, and three people drowned by driving into flooded waters. Considered the worst flood on record in the city, Roanoke sustained $225 million in damage, with 3,100 damaged homes and businesses. There was also flooding in Richmond after the James River crested at the second-highest level on record. Throughout Virginia, damage was estimated at $753 million, making it the state's costliest flood at the time, and there were 22 deaths. In West Virginia, 27 river gauging stations were 1 in 100 year events, mostly along the Potomac and Monongahela basins. As most of West Virginia's liveable land is along flood plains, the river flooding caused heavy damage in the state, mostly in the eastern portion. High waters washed away topsoil and thousands of trees, and over 13,000 homes and businesses were damaged or destroyed in the state. Damage was estimated at nearly $700 million, making it West Virginia's costliest flood, and there were 38 deaths. Flooding also affected Maryland, although to a lesser degree than neighboring Virginia, with $21 million in damage and one death. There was also tidal flooding in the state along the Chesapeake Bay from the storm, which washed away beaches just weeks after Hurricane Gloria affected the coastline. In Pennsylvania, flooding was worst along the Monongahela River in the state's southwest portion. During the storm, a power company opened the flood gates of the Lake Lynn dam along the river to preserve its integrity, triggering a class action lawsuit that ultimately failed. The floods damaged or destroyed 3,349 houses in Pennsylvania, causing $83 million in damage, as well as one death. Overall damage was estimated at $1.4 billion, which would have been the fourth costliest United States hurricanes if it were a tropical cyclone, and there were 62 overall deaths. The flooding spurred changes to warning practices by the National Weather Service and the Government of Virginia. In December 2011, the United States Army Corps of Engineers completed a flood mitigation project in Roanoke, Virginia that began following the 1985 floods. ==Meteorological history== Early on October 26, a tropical depression formed in the central Gulf of Mexico, and intensified into Hurricane Juan while meandering northward. The storm had a large wind field and was somewhat subtropical in nature. Due to weak steering currents, Juan looped once offshore Louisiana and later looped again over the state, weakening into a tropical storm over land on October 29. The storm turned eastward and later northeastward, striking just west of Pensacola, Florida late on October 31. Juan turned to the north over land and became extratropical on November 1 over Tennessee. After the remnants of Juan continued to the north into Canada, it spawned an occluded low formed in the Tennessee Valley.〔 This low continued to the east through North Carolina, bringing moderate rainfall throughout the region, and saturating soils; overcast skies and the weak sunlight of early November prevented much of the rains from evaporating. On November 3, while the low was located over North Carolina, a stationary cold front extended from the Gulf of Mexico through Michigan, which absorbed the remnants of Juan. That day, a low pressure area developed in the Gulf of Mexico south of the Florida panhandle and tracked to the northeast along the front, bringing a plume of warm tropical air into the east-central United States;〔 the previously erratic motion of Hurricane Juan allowed this flow of moisture to extend into the mid-Atlantic.〔 As a result, dew points reached over in North Carolina, which is unusually high for the time of year. As the storm moved through the Carolinas, it produced an area of convection, or thunderstorms, that extended to the north and west. The low stalled over Virginia on November 5 to the west of Washington, D.C.,〔 before turning to the east and exiting into the Atlantic Ocean, with rainfall ending on November 6. 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「1985 Election day floods」の詳細全文を読む スポンサード リンク
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