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A storm surge, storm flood, tidal surge or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low pressure weather systems (such as tropical cyclones and strong extratropical cyclones). Its severity is affected by the shallowness and orientation of the water body relative to storm path, as well as the timing of tides. Most casualties during tropical cyclones occur as the result of storm surges. It is a measure of the rise of water beyond what would be expected by the normal movement related to tides.
The two main meteorological factors contributing to a storm surge are a long fetch of winds spiraling inward toward the storm, and a low-pressure-induced dome of water drawn up under and trailing the storm's center.
The deadliest storm surge on record was the 1970 Bhola cyclone, which killed up to 500,000 people in the area of the Bay of Bengal. The low-lying coast of the Bay of Bengal is particularly vulnerable to surges caused by tropical cyclones.The deadliest storm surge in the twenty-first century was caused by the Cyclone Nargis, which killed more than 138,000 people in Myanmar in May 2008. The next deadliest in this century was caused by the Typhoon Haiyan (Yolanda), which killed more than 6,000 people in the central Philippines in 2013 and resulted in economic losses estimated at $14 billion (USD).
The Galveston Hurricane of 1900, a Category 4 hurricane that struck Galveston, Texas, drove a devastating surge ashore; between 6,000 and 12,000 lives were lost, making it the deadliest natural disaster ever to strike the United States.
The highest storm tide noted in historical accounts was produced by the 1899 Cyclone Mahina, estimated at almost 44 ft (13 metres) at Bathurst Bay, Australia, but research published in 2000 concluded that the majority of this likely was wave run-up because of the steep coastal topography. In the United States, one of the greatest recorded storm surges was generated by Hurricane Katrina on August 29, 2005, which produced a maximum storm surge of more than 28 ft (8 metres) in southern Mississippi, with a storm surge height of 27.8 ft (8.5 m) in Pass Christian. Another record storm surge occurred in this same area from Hurricane Camille in 1969, with a storm tide of 24.6 ft (7.5 m), also at Pass Christian. A storm surge of 14 ft (4.2 m) occurred in New York City during Hurricane Sandy in October 2012.
At least five processes can be involved in altering tide levels during storms:
The pressure effects of a tropical cyclone will cause the water level in the open ocean to rise in regions of low atmospheric pressure and fall in regions of high atmospheric pressure. The rising water level will counteract the low atmospheric pressure such that the total pressure at some plane beneath the water surface remains constant. This effect is estimated at a 10 mm (0.39 in) increase in sea level for every millibar (hPa) drop in atmospheric pressure.
Strong surface winds cause surface currents at a 45° angle to the wind direction, by an effect known as the Ekman Spiral. Wind stresses cause a phenomenon referred to as "wind set-up", which is the tendency for water levels to increase at the downwind shore and to decrease at the upwind shore. Intuitively, this is caused by the storm blowing the water toward one side of the basin in the direction of its winds. Because the Ekman Spiral effects spread vertically through the water, the effect is proportional to depth. The pressure effect and the wind set-up on an open coast will be driven into bays in the same way as the astronomical tide.
The Earth's rotation causes the Coriolis effect, which bends currents to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. When this bend brings the currents into more perpendicular contact with the shore, it can amplify the surge, and when it bends the current away from the shore it has the effect of lessening the surge.
The effect of waves, while directly powered by the wind, is distinct from a storm's wind-powered currents. Powerful wind whips up large, strong waves in the direction of its movement.Although these surface waves are responsible for very little water transport in open water, they may be responsible for significant transport near the shore. When waves are breaking on a line more or less parallel to the beach, they carry considerable water shoreward. As they break, the water particles moving toward the shore have considerable momentum and may run up a sloping beach to an elevation above the mean water line, which may exceed twice the wave height before breaking.
The rainfall effect is experienced predominantly in estuaries. Hurricanes may dump as much as 12 in (300 mm) of rainfall in 24 hours over large areas and higher rainfall densities in localized areas. As a result, surface runoff can quickly flood streams and rivers. This can increase the water level near the head of tidal estuaries as storm-driven waters surging in from the ocean meet rainfall flowing downstream into the estuary.
In addition to the above processes, surge and wave heights on shore are also affected by the flow of water over the underlying topography, i.e. the configuration and bathymetry of the ocean bottom and affected coastal area. A narrow shelf, for example, or one that has a steep drop from the shoreline and subsequently produces deep water in proximity to the shoreline, tends to produce a lower surge but a higher and more powerful wave. This situation is well exemplified by the southeast coast of Florida. The edge of the Floridian Plateau, where the water depths reach 91 metres (299 ft), lies just 3,000 m (9,800 ft) offshore of Palm Beach; just 7,000 m (23,000 ft) offshore, the depth increases to over 180 m (590 ft). The 180 m (590 ft) depth contour followed southward from Palm Beach County lies more than 30,000 m (98,000 ft) to the east of the Florida Keys.
Conversely, coastlines along North America such as those along the Gulf of Mexico coast from Texas to Florida, and Asia such as the Bay of Bengal, have long, gently sloping shelves and shallow water depths. On the Gulf side of Florida, the edge of the Floridian Plateau lies more than 160 kilometres (99 mi) offshore of Marco Island in Collier County. Florida Bay, lying between the Florida Keys and the mainland, is also very shallow; depths typically vary between 0.3 m (0.98 ft) and 2 m (6.6 ft). These areas are subject to higher storm surges with smaller waves. This difference is because in deeper water, a surge can be dispersed down and away from the hurricane. However, upon entering a shallow, gently sloping shelf, the surge cannot be disperse, but is driven ashore by the wind stresses of the hurricane. Topography of the land surface is another important element in storm surge extent. Areas where the land lies less than a few meters above sea level are at particular risk from storm surge inundation.
For a given topography and bathymetry the surge height is not solely affected by peak wind speed; the size of the storm also affects the peak surge. With any storm, the area of piled up water can flow out of the storm perimeter, and this escape mechanism is reduced in proportion to the surge force (for the same peak wind speed) when the storm covers more area (storm perimeter length per area is inversely proportional to a circular storm's diameter).
Similar to tropical cyclones, extratropical cyclones cause an offshore rise of water. However, unlike most tropical cyclone storm surges, extratropical cyclones can cause higher water levels across a large area for longer periods of time, depending on the system.
In North America, extratropical storm surges may occur on the Pacific and Alaska coasts, and north of 31°N on the Atlantic Coast. Coasts with sea ice may experience an "ice tsunami" causing significant damage inland.Extratropical storm surges may be possible further south for the Gulf coast mostly during the wintertime, when extratropical cyclones affect the coast, such as in the 1993 Storm of the Century.
November 9–13, 2009, marked a significant extratropical storm surge event on the United States east coast when the remnants of Hurricane Ida developed into a Nor'easter off the southeast U.S. coast. During the event, winds from the east were present along the northern periphery of the low pressure center for a number of days, forcing water into locations such as Chesapeake Bay. Water levels rose significantly and remained as high as 8 feet (2.4 m) above normal in numerous locations throughout the Chesapeake for a number of days as water was continually built-up inside the estuary from the onshore winds and freshwater rains flowing into the bay. In many locations, water levels were shy of records by only 0.1 feet (3 cm).[ citation needed ]
Surge can be measured directly at coastal tidal stations as the difference between the forecast tide and the observed rise of water.Another method of measuring surge is by the deployment of pressure transducers along the coastline just ahead of an approaching tropical cyclone. This was first tested for Hurricane Rita in 2005. These types of sensors can be placed in locations that will be submerged and can accurately measure the height of water above them.
After surge from a cyclone has receded, teams of surveyors map high-water marks (HWM) on land, in a rigorous and detailed process that includes photographs and written descriptions of the marks. HWMs denote the location and elevation of flood waters from a storm event. When HWMs are analyzed, if the various components of the water height can be broken out so that the portion attributable to surge can be identified, then that mark can be classified as storm surge. Otherwise, it is classified as storm tide. HWMs on land are referenced to a vertical datum (a reference coordinate system). During evaluation, HWMs are divided into four categories based on the confidence in the mark; only HWMs evaluated as "excellent" are used by National Hurricane Center in post-storm analysis of the surge.
Two different measures are used for storm tide and storm surge measurements. Storm tide is measured using a geodetic vertical datum (NGVD 29 or NAVD 88). Since storm surge is defined as the rise of water beyond what would be expected by the normal movement caused by tides, storm surge is measured using tidal predictions, with the assumption that the tide prediction is well-known and only slowly varying in the region subject to the surge. Since tides are a localized phenomenon, storm surge can only be measured in relationship to a nearby tidal station. Tidal bench mark information at a station provides a translation from the geodetic vertical datum to mean sea level (MSL) at that location, then subtracting the tidal prediction yields a surge height above the normal water height.
The National Hurricane Center forecasts storm surge using the SLOSH model, which is an abbreviation for Sea, Lake and Overland Surges from Hurricanes. The model is accurate to within 20 percent. SLOSH inputs include the central pressure of a tropical cyclone, storm size, the cyclone's forward motion, its track, and maximum sustained winds. Local topography, bay and river orientation, depth of the sea bottom, astronomical tides, as well as other physical features, are taken into account in a predefined grid referred to as a SLOSH basin. Overlapping SLOSH basins are defined for the southern and eastern coastline of the continental U.S. Some storm simulations use more than one SLOSH basin; for instance, Hurricane Katrina SLOSH model runs used both the Lake Ponchartrain / New Orleans basin, and the Mississippi Sound basin, for the northern Gulf of Mexico landfall. The final output from the model run will display the maximum envelope of water, or MEOW, that occurred at each location.
To allow for track or forecast uncertainties, usually several model runs with varying input parameters are generated to create a map of MOMs, or Maximum of Maximums.For hurricane evacuation studies, a family of storms with representative tracks for the region, and varying intensity, eye diameter, and speed, are modeled to produce worst-case water heights for any tropical cyclone occurrence. The results of these studies are typically generated from several thousand SLOSH runs. These studies have been completed by the United States Army Corps of Engineers, under contract to the Federal Emergency Management Agency, for several states and are available on their Hurricane Evacuation Studies (HES) website. They include coastal county maps, shaded to identify the minimum category of hurricane that will result in flooding, in each area of the county.
Although meteorological surveys alert about hurricanes or severe storms, in the areas where the risk of coastal flooding is particularly high, there are specific storm surge warnings. These have been implemented, for instance, in the Netherlands,Spain, the United States, and the United Kingdom.
A prophylactic method introduced after the North Sea Flood of 1953 is the construction of dams and storm-surge barriers (flood barriers). They are open and allow free passage, but close when the land is under threat of a storm surge. Major storm surge barriers are the Oosterscheldekering and Maeslantkering in the Netherlands, which are part of the Delta Works project; the Thames Barrier protecting London; and the Saint Petersburg Dam in Russia.
Another modern development (in use in the Netherlands) is the creation of housing communities at the edges of wetlands with floating structures, restrained in position by vertical pylons.Such wetlands can then be used to accommodate runoff and surges without causing damage to the structures while also protecting conventional structures at somewhat higher low-lying elevations, provided that dikes prevent major surge intrusion.
For mainland areas, storm surge is more of a threat when the storm strikes land from seaward, rather than approaching from landward.
Water can also be sucked away from shore prior to a storm surge. This was the case on the western Florida coast in 2017, just before Hurricane Irma made landfall, uncovering land usually underwater.This phenomenon is known as a reverse storm surge, or a negative storm surge.
In meteorology, a cyclone is a large scale air mass that rotates around a strong center of low atmospheric pressure. Cyclones are characterized by inward spiraling winds that rotate about a zone of low pressure. The largest low-pressure systems are polar vortices and extratropical cyclones of the largest scale. Warm-core cyclones such as tropical cyclones and subtropical cyclones also lie within the synoptic scale. Mesocyclones, tornadoes, and dust devils lie within smaller mesoscale. Upper level cyclones can exist without the presence of a surface low, and can pinch off from the base of the tropical upper tropospheric trough during the summer months in the Northern Hemisphere. Cyclones have also been seen on extraterrestrial planets, such as Mars, Jupiter, and Neptune. Cyclogenesis is the process of cyclone formation and intensification. Extratropical cyclones begin as waves in large regions of enhanced mid-latitude temperature contrasts called baroclinic zones. These zones contract and form weather fronts as the cyclonic circulation closes and intensifies. Later in their life cycle, extratropical cyclones occlude as cold air masses undercut the warmer air and become cold core systems. A cyclone's track is guided over the course of its 2 to 6 day life cycle by the steering flow of the subtropical jet stream.
The Saffir–Simpson hurricane wind scale (SSHWS), formerly the Saffir–Simpson hurricane scale (SSHS), classifies hurricanes – Western Hemisphere tropical cyclones – that exceed the intensities of tropical depressions and tropical storms – into five categories distinguished by the intensities of their sustained winds.
The 1938 New England Hurricane was one of the deadliest and most destructive tropical cyclones to strike Long Island, New York, and New England. The storm formed near the coast of Africa on September 9, becoming a Category 5 hurricane on the Saffir-Simpson Hurricane Scale, before making landfall as a Category 3 hurricane on Long Island on September 21. It is estimated that the hurricane killed 682 people, damaged or destroyed more than 57,000 homes, and caused property losses estimated at $306 million. Damaged trees and buildings were still seen in the affected areas as late as 1951. It remains the most powerful and deadliest hurricane in recorded New England history, perhaps eclipsed in landfall intensity only by the Great Colonial Hurricane of 1635.
The 1975 Atlantic hurricane season featured the first tropical storm to be upgraded to a hurricane based solely on satellite imagery – Hurricane Doris. The season officially began on June 1 and lasted until November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. The season was near average, with nine tropical storms forming, of which six became hurricanes. Three of those six became major hurricanes, which are Category 3 or higher on the Saffir–Simpson scale. The first system, Tropical Depression One, developed on June 24. Tropical Storm Amy in July caused minor beach erosion and coastal flooding from North Carolina to New Jersey, and killed one person when a ship capsized offshore North Carolina. Hurricane Blanche brought strong winds to portions of Atlantic Canada, leaving about $6.2 million (1975 USD) in damage. Hurricane Caroline brought high tides and flooding to northeastern Mexico and Texas, with two drownings in the latter.
The Groundhog Day gale was a severe winter storm that hit the northeastern United States and southeastern Canada on February 2, 1976.
Hurricane Gloria was the first significant tropical cyclone to strike the northeastern United States since Hurricane Agnes in 1972 and the first major storm to affect New York and Long Island directly since Hurricane Donna in 1960. It was a powerful Cape Verde hurricane that formed during the 1985 Atlantic hurricane season, originating from a tropical wave on September 16 in the eastern Atlantic Ocean. After remaining a weak tropical cyclone for several days, Gloria intensified into a hurricane on September 22 north of the Lesser Antilles. During that time, the storm had moved generally westward, although it turned to the northwest due to a weakening of the ridge. Gloria quickly intensified on September 24, and the next day reached peak winds of 145 mph (230 km/h). The hurricane weakened before striking the Outer Banks of North Carolina on September 27. Later that day, Gloria made two subsequent landfalls on Long Island and later western Connecticut, before becoming extratropical on September 28 over New England. The remnants moved through Atlantic Canada, eventually dissipating on October 2.
The 1957 Atlantic hurricane season featured the one of longest travelling tropical cyclones in the Atlantic basin, Hurricane Carrie. Nevertheless, the season was generally inactive with eight tropical storms – two of which went unnamed – and three hurricanes, two of which intensified further to attain major hurricane intensity. The season officially began on June 15 and ended on November 15, though the year's first tropical cyclone developed prior to the start of the season on June 8. The final storm dissipated on October 27, well before the official end of the season. The strongest hurricane of the year was Carrie, which reached the equivalent of a Category 4 hurricane on the Saffir–Simpson hurricane scale on two separate occasions in the open Atlantic; Carrie later caused the sinking of the German ship Pamir southwest of the Azores, resulting in 80 deaths.
The 1954 Atlantic hurricane season resulted in over $750 million in damage, the most of any season at the time. It was an above-average season. The season officially began on June 15, and nine days later the first named storm developed. Hurricane Alice developed in the Gulf of Mexico and moved inland along the Rio Grande, producing significant precipitation and record flooding that killed 55 people. Activity was slow until late August; only Barbara, a minimal tropical storm, developed in July. In the span of two weeks, hurricanes Carol and Edna followed similar paths before both striking New England as major hurricanes. The latter became the costliest hurricane in Maine's history.
On August 27, 1893, a major hurricane which came to be known as the Sea Islands Hurricane struck the United States near Savannah, Georgia. It was one of three deadly hurricanes during the 1893 Atlantic hurricane season; the storm killed an estimated 1,000–2,000 people, mostly from storm surge. This is also the storm that made United States Life-Saving Service Keeper Dunbar Davis famous.
Hurricane Dennis caused flooding in North Carolina and the Mid-Atlantic states in early September 1999, which would later be compounded by Hurricane Floyd. The fifth tropical cyclone of the season, Dennis developed from a tropical wave to the north of Puerto Rico on August 24. Originally a tropical depression, the system moved west-northwestward and strengthened into a tropical storm despite unfavorable wind shear. The storm became a hurricane by August 26. After striking the Abaco Islands, conditions improved, allowing for Dennis to strengthen into a Category 2 on the Saffir–Simpson scale by August 28. Around this time, Dennis began to move parallel to the Southeastern United States. Early on August 30, the storm peaked with winds of 105 mph (165 km/h). By the following day, steering currents collapsed and the storm interacted with a cold front, causing Dennis to move erratically offshore North Carolina. Wind shear and cold air associated with the front weakened Dennis to a tropical storm on September 1 and removed some of its tropical characteristics. Eventually, warmer ocean temperatures caused some re-strengthening. By September 4, Dennis turned northwestward and made landfall in Cape Lookout, North Carolina, as a strong tropical storm. The storm slowly weakened inland, before transitioning into an extratropical cyclone over western New York on September 7.
Hurricane Charley was the first hurricane to threaten the East Coast of the United States since Hurricane Gloria the previous year. The third tropical storm and second hurricane of the season, Charley formed as a subtropical low on August 13 along the Florida panhandle. After moving off the coast of South Carolina, the system transitioned into a tropical cyclone and intensified into a tropical storm on August 15. Charley later attained hurricane status before moving across eastern North Carolina. It gradually weakened over the north Atlantic Ocean before transitioning into an extratropical cyclone on August 20. Charley's remnants remained identifiable for over a week until after crossing the British Isles and dissipating on August 30.
The 1991 Perfect Storm, also known as The No-Name Storm and the Halloween Gale/Storm, was a nor'easter that absorbed Hurricane Grace, and ultimately evolved into a small unnamed hurricane itself late in its life cycle. The initial area of low pressure developed off the coast of Atlantic Canada on October 29. Forced southward by a ridge to its north, it reached its peak intensity as a large and powerful cyclone. The storm lashed the east coast of the United States with high waves and coastal flooding before turning to the southwest and weakening. Moving over warmer waters, the system transitioned into a subtropical cyclone before becoming a tropical storm. It executed a loop off the Mid-Atlantic states and turned toward the northeast. On November 1, the system evolved into a full-fledged hurricane, with peak sustained winds of 75 miles per hour (120 km/h), although the National Hurricane Center left it unnamed to avoid confusion amid media interest in the precursor extratropical storm. It later received the name "the Perfect Storm" after a conversation between Boston National Weather Service forecaster Robert Case and author Sebastian Junger. The system was the twelfth and final tropical cyclone, the eighth tropical storm, and fourth hurricane in the 1991 Atlantic hurricane season. The tropical system weakened, striking Nova Scotia as a tropical storm before dissipating.
The 1926 Nassau hurricane also known as the San Liborio hurricane or The Great Bahamas Hurricane of 1926, in Puerto Rico, was a destructive Category 4 hurricane that affected the Bahamas at peak intensity. Although it weakened considerably before its Florida landfall, it was one of the most severe storms to affect the Bahamian capital Nassau and the island of New Providence in several years until the 1928 Okeechobee hurricane, which occurred just two years later. The storm also delivered flooding rains and loss of crops to the southeastern United States and Florida.
Hurricane Gabrielle was a North Atlantic hurricane that caused flooding in both Florida and Newfoundland in September of 2001. It developed in the Gulf of Mexico on the same day as the September 11 attacks; after the attacks, flights were canceled nationwide for two days, and when Gabrielle struck Florida on September 14, it caused a day of additional cancellations. The storm moved ashore with winds of 70 mph (110 km/h) near Venice, a city located south of the Tampa Bay area. The combination of the winds and heavy rainfall, which peaked at 15.1 in (380 mm) in Parrish, left 570,000 customers without power along the west coast and 126,000 customers without power on the east coast. The storm caused about $230 million (2001 USD) in damage in Florida. In the Gulf of Mexico, high waves contributed to two deaths, one of which was indirect; there was also a death due to flooding in Winter Haven.
Tropical Storm Alberto was the first tropical storm of the 2006 Atlantic hurricane season. Forming on June 10 in the northwestern Caribbean, the storm moved generally to the north, reaching a maximum intensity of 70 mph (110 km/h) before weakening and moving ashore in the Big Bend area of Florida on June 13. Alberto then moved through eastern Georgia, North Carolina, and Virginia as a tropical depression before becoming extratropical on June 14.
Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of producing anything from cloudiness and mild showers to heavy gales, thunderstorms, blizzards, and tornadoes. These types of cyclones are defined as large scale (synoptic) low pressure weather systems that occur in the middle latitudes of the Earth. In contrast with tropical cyclones, extratropical cyclones produce rapid changes in temperature and dew point along broad lines, called weather fronts, about the center of the cyclone.
Hurricane Flossy originated from a tropical disturbance in the eastern Pacific Ocean and moved across Central America into the Gulf of Mexico as a tropical depression on September 21, 1956, which became a tropical storm on September 22 and a hurricane on September 23. The hurricane peaked with maximum sustained winds of 90 mph (150 km/h) before it struck the central Gulf coast of the United States as a Category 1 hurricane on September 24, and evolved into an extratropical cyclone on September 25. It was the first hurricane to affect oil refining in the Gulf of Mexico. The tropical cyclone led to flooding in New Orleans, and broke a drought across the eastern United States. The death toll was 15, and total damages reached $24.8 million (1956 USD).
Tropical Storm Edouard brought coastal and minor inland flooding to Louisiana and Texas in August 2008. The fifth tropical cyclone and fifth named storm of the hurricane season, Edouard developed from a trough in the northern Gulf of Mexico on August 3. After developing into a tropical depression, it gradually strengthened and was upgraded to Tropical Storm Edouard on August 4. However, northerly wind shear initially halted any further significant intensification and also caused the storm to struggle to maintain deep convection over the center. Edouard eventually intensified further and peaked as a strong tropical storm with winds of 65 mph (100 km/h) on August 5. Shortly thereafter, the storm made landfall near Gilchrist, Texas later that day. Edouard quickly weakened and was downgraded to tropical depression by early on August 6, six hours before degenerated into a remnant low pressure area.
The 1898 Georgia hurricane was a major hurricane that hit the U.S. state of Georgia, as well as the strongest on record in the state. It was first observed on September 29, although modern researchers estimated that it developed four days earlier to the east of the Lesser Antilles. The hurricane maintained a general northwest track throughout its duration, and it reached peak winds of 135 mph (215 km/h) on October 2. That day, it made landfall on Cumberland Island in Camden County, Georgia, causing record storm surge flooding. The hurricane caused heavy damage throughout the region, and killed at least 179 people. Impact was most severe in Brunswick, where a 16 ft (4.9 m) storm surge was recorded. Overall damage was estimated at $1.5 million (1898 USD), most of which occurred in Georgia. In extreme northeastern Florida, strong winds nearly destroyed the city of Fernandina, while light crop damage was reported in southern South Carolina. After moving ashore, the hurricane quickly weakened and traversed much of North America; it continued northwestward until reaching the Ohio Valley and turning northeastward, and it was last observed on October 6 near Newfoundland.
The November 2011 Bering Sea cyclone was one of the most powerful extratropical cyclones to affect Alaska on record. On November 8, the National Weather Service (NWS) began issuing severe weather warnings, saying that this was a near-record storm in the Bering Sea. It rapidly deepened from 973 mb (28.7 inHg) to 948 mb (28.0 inHg) in just 24 hours before bottoming out at 943 mbar, roughly comparable to a Category 3 or 4 hurricane. The storm had been deemed life-threatening by many people. The storm had a forward speed of at least 60 mph (97 km/h) before it had reached Alaska. The storm began affecting Alaska in the late hours of November 8, 2011. The highest gust recorded was 93 mph (150 km/h) on Little Diomede Island. One person was reported missing after being swept into the Bering Sea, and he was later pronounced dead.
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