Hurricane Ophelia (2011)
Encyclopedia
Hurricane Ophelia was a relatively large Atlantic tropical cyclone that affected the Leeward Islands
Leeward Islands
The Leeward Islands are a group of islands in the West Indies. They are the northern islands of the Lesser Antilles chain. As a group they start east of Puerto Rico and reach southward to Dominica. They are situated where the northeastern Caribbean Sea meets the western Atlantic Ocean...

, Bermuda
Bermuda
Bermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, its nearest landmass is Cape Hatteras, North Carolina, about to the west-northwest. It is about south of Halifax, Nova Scotia, Canada, and northeast of Miami, Florida...

, and Newfoundland during September and October 2011. The seventeenth tropical cyclone, sixteenth tropical storm, fourth hurricane, and third major hurricane of the annual hurricane season
2011 Atlantic hurricane season
The 2011 Atlantic hurricane season is tied for the third most active season on record with 1887, 1995 and 2010. It began on June 1, 2011, and ended on November 30, 2011, however these dates conventionally delimit the period of each year when most tropical cyclones develop in the Atlantic basin...

, Ophelia developed from a low-pressure area associated with a tropical wave
Tropical wave
Tropical waves, easterly waves, or tropical easterly waves, also known as African easterly waves in the Atlantic region, are a type of atmospheric trough, an elongated area of relatively low air pressure, oriented north to south, which move from east to west across the tropics causing areas of...

 in the central Atlantic, approximately halfway between the Cape Verde Islands
Cape Verde
The Republic of Cape Verde is an island country, spanning an archipelago of 10 islands located in the central Atlantic Ocean, 570 kilometres off the coast of Western Africa...

 and the Lesser Antilles
Lesser Antilles
The Lesser Antilles are a long, partly volcanic island arc in the Western Hemisphere. Most of its islands form the eastern boundary of the Caribbean Sea with the Atlantic Ocean, with the remainder located in the southern Caribbean just north of South America...

 on September 17. Tracking generally west-northwest, Ophelia was upgraded to a tropical storm on September 22, and reached an initial peak of 65 miles per hour (104.6 km/h) on September 22, before the storm began to enter an area of higher wind shear
Wind shear
Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...

. While located a few hundred miles to the east
East
East is a noun, adjective, or adverb indicating direction or geography.East is one of the four cardinal directions or compass points. It is the opposite of west and is perpendicular to north and south.By convention, the right side of a map is east....

 of the Lesser Antilles, Ophelia was downgraded into a remnant low after a reconnaissance aircraft found that the storm had a weak circulation, characterized with very minimal thunderstorm activity
Atmospheric convection
Atmospheric convection is the result of a parcel-environment instability, or temperature difference, layer in the atmosphere. Different lapse rates within dry and moist air lead to instability. Mixing of air during the day which expands the height of the planetary boundary layer leads to...

. However, the following day, the remnants of the system began to reorganize, and on September 27, the National Hurricane Center
National Hurricane Center
The National Hurricane Center , located at Florida International University in Miami, Florida, is the division of the National Weather Service responsible for tracking and predicting weather systems within the tropics between the Prime Meridian and the 140th meridian west poleward to the 30th...

 began reissuing advisories on what was now tropical depression Ophelia. Gradually organizing, Ophelia regained tropical storm status early on September 28, and was classified as a Category 1 hurricane
Saffir-Simpson Hurricane Scale
The Saffir–Simpson Hurricane Scale , or the Saffir–Simpson Hurricane Wind Scale , 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 next afternoon.

While moving north
North
North is a noun, adjective, or adverb indicating direction or geography.North is one of the four cardinal directions or compass points. It is the opposite of south and is perpendicular to east and west.By convention, the top side of a map is north....

 to the northeast of the Leeward Islands
Leeward Islands
The Leeward Islands are a group of islands in the West Indies. They are the northern islands of the Lesser Antilles chain. As a group they start east of Puerto Rico and reach southward to Dominica. They are situated where the northeastern Caribbean Sea meets the western Atlantic Ocean...

, Ophelia began to undergo rapid intensification
Rapid deepening
Rapid deepening, also known as rapid intensification, is a meteorological condition that occurs when the minimum sea-level atmospheric pressure of a tropical cyclone decreases drastically in a short period of time. The National Weather Service describes rapid deepening as a decrease of...

, and reached Category 2 hurricane during the pre-dawn hours of September 30, and Category 3 hurricane status later that morning. While passing to the east of Bermuda on October 1, Ophelia strengthened into a Category 4 hurricane, and also reached a peak intensity of 140 miles per hour (225.3 km/h) late that night. However, the storm began to weaken as Ophelia entered cooler sea surface temperatures
Sea surface temperature
Sea surface temperature is the water temperature close to the oceans surface. The exact meaning of surface varies according to the measurement method used, but it is between and below the sea surface. Air masses in the Earth's atmosphere are highly modified by sea surface temperatures within a...

 and higher wind shear, and was subsequently downgraded to a Category 3 hurricane early on October 2. While located several hundred miles to the south of Newfoundland, Ophelia weakened into a Category 2 hurricane, and then further into a tropical storm by early on October 3, when Ophelia made landfall on the Avalon Peninsula
Avalon Peninsula
The Avalon Peninsula is a large peninsula that makes up the southeast portion of the island of Newfoundland.The peninsula is home to 257,223 people, which is approximately 51% of Newfoundland's population in 2009, and is the location of the provincial capital, St. John's. It is connected to the...

 of Newfoundland with maximum sustained wind
Maximum sustained wind
The maximum sustained winds associated with a tropical cyclone are a common indicator of the intensity of the storm. Within a mature tropical cyclone, they are found within the eyewall at a distance defined as the radius of maximum wind, or RMW. Unlike gusts, the value of these winds are...

s of 60 miles per hour (95 km/h).

Meteorological history

In mid-September, a well-defined tropical wave emerged off the African coastline. Moving westward, the disturbance began to gather organization, and became very well defined on September 20. Subsequently, the National Hurricane Center started issuing advisories on Tropical Storm Ophelia. Almost as soon as it became a tropical storm, vertical wind shear
Wind shear
Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...

 began impacting the system. Ophelia slowly strengthened despite the unfavorable conditions and attained winds of 65 mph (100 km/h) on September 22. The system briefly weakened to a minimal tropical storm before strengthening again. However, because of the extremely strong wind shear, Ophelia was ripped apart and dissipated into a post-tropical remnant low on September 25. Wind shear remained strong, but not as strong as before. Thus, during the afternoon hours of September 27, Ophelia was able to develop convection near its center, and was designated a tropical depression. Ophelia gradually strengthened further into a tropical storm as it passed to the north of the Leeward Islands
Leeward Islands
The Leeward Islands are a group of islands in the West Indies. They are the northern islands of the Lesser Antilles chain. As a group they start east of Puerto Rico and reach southward to Dominica. They are situated where the northeastern Caribbean Sea meets the western Atlantic Ocean...

. In Dominica
Dominica
Dominica , officially the Commonwealth of Dominica, is an island nation in the Lesser Antilles region of the Caribbean Sea, south-southeast of Guadeloupe and northwest of Martinique. Its size is and the highest point in the country is Morne Diablotins, which has an elevation of . The Commonwealth...

, heavy rains from the storm caused widespread flooding. During the afternoon hours of September 29, despite the relatively unfavorable environment, Ophelia strengthened into a Category 1 hurricane.

As wind shear relaxed, early on September 30, Ophelia rapidly intensified
Rapid deepening
Rapid deepening, also known as rapid intensification, is a meteorological condition that occurs when the minimum sea-level atmospheric pressure of a tropical cyclone decreases drastically in a short period of time. The National Weather Service describes rapid deepening as a decrease of...

 and became a Category 2 hurricane. Later that day, Ophelia further strengthened into a Category 3 hurricane, becoming the third major hurricane of the season. The eye of Ophelia passed directly over a NOAA buoy
Buoy
A buoy is a floating device that can have many different purposes. It can be anchored or allowed to drift. The word, of Old French or Middle Dutch origin, is now most commonly in UK English, although some orthoepists have traditionally prescribed the pronunciation...

 early on October 1, which reported sustained winds of 96 mph (155 km/h) and a pressure of 952 mbar (28.11 inHg). The intensification trend continued, and Ophelia strengthened further to a Category 4 hurricane late that day east of Bermuda
Bermuda
Bermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, its nearest landmass is Cape Hatteras, North Carolina, about to the west-northwest. It is about south of Halifax, Nova Scotia, Canada, and northeast of Miami, Florida...

. Through the following day (Sunday), increasing southwesterly wind shear and cooler water temperatures combined to cause Ophelia to progressively weaken back into a Category 1 hurricane by evening and weakened to a tropical storm during the morning hours of October 3. Several hours later, Ophelia was declared as a post-tropical cyclone soon after making landfall on the Avalon Peninsula
Avalon Peninsula
The Avalon Peninsula is a large peninsula that makes up the southeast portion of the island of Newfoundland.The peninsula is home to 257,223 people, which is approximately 51% of Newfoundland's population in 2009, and is the location of the provincial capital, St. John's. It is connected to the...

 in Newfoundland.

Preparations and impact

Lesser Antilles

Though the center of Ophelia remained 205 mi (330 km) east of the Lesser Antilles
Lesser Antilles
The Lesser Antilles are a long, partly volcanic island arc in the Western Hemisphere. Most of its islands form the eastern boundary of the Caribbean Sea with the Atlantic Ocean, with the remainder located in the southern Caribbean just north of South America...

, its outer bands
Rainband
A rainband is a cloud and precipitation structure associated with an area of rainfall which is significantly elongated. Rainbands can be stratiform or convective, and are generated by differences in temperature. When noted on weather radar imagery, this precipitation elongation is referred to as...

 produced heavy rains across the region. In Dominica
Dominica
Dominica , officially the Commonwealth of Dominica, is an island nation in the Lesser Antilles region of the Caribbean Sea, south-southeast of Guadeloupe and northwest of Martinique. Its size is and the highest point in the country is Morne Diablotins, which has an elevation of . The Commonwealth...

, more than 4 in (101.6 mm) of rain fell across parts of the country, triggering flooding along several rivers. Nearly 1,600 people were stranded and many cars were washed away by the floods while landslides isolated several communities. Schools, businesses, government offices and Canefield Airport
Canefield Airport
Canefield Airport , is the airport serving Roseau, Dominica. It is one of only two airports in the island nation of Dominica, the other being Melville Hall Airport....

 were closed on September 28 due to the storm. Gusty winds, reaching 37 mph (60 km/h) at times, and scattered thunderstorms affected portions of Guadeloupe
Guadeloupe
Guadeloupe is an archipelago located in the Leeward Islands, in the Lesser Antilles, with a land area of 1,628 square kilometres and a population of 400,000. It is the first overseas region of France, consisting of a single overseas department. As with the other overseas departments, Guadeloupe...

.

Bermuda

Following Ophelia's upgrade to hurricane status on September 29, the Bermuda Weather Service
Bermuda Weather Service
The Bermuda Weather Service is Bermuda's national meteorological service. It provides public, marine, tropical and aviation weather forecasts as well as warnings and climatolological services. The service began operations under contract from the Department of Airport Operations, Ministry of...

 (BWS) issued a tropical storm watch
Tropical cyclone warnings and watches
Warnings and watches are two levels of alert issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of tropical storm or hurricane intensity. They are notices to the local population and civil authorities to make appropriate...

 for all of Bermuda
Bermuda
Bermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, its nearest landmass is Cape Hatteras, North Carolina, about to the west-northwest. It is about south of Halifax, Nova Scotia, Canada, and northeast of Miami, Florida...

. Over the following days, the threat of damaging winds gradually decreased as the storm's forecast track took it far enough east of the territory to spare the region of a direct hit. Correspondingly, the BWS discontinued the watch on the evening of October 1. Four flights from the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 to Bermuda were canceled due to stormy conditions. Along the coast, the Department of Parks raised high surf warnings for the entire south shore and temporarily closed Horseshoe Beach. Additionally, a few local events were postponed. Passing roughly 140 mi (220 km) east of Bermuda, the outer bands of Ophelia produced 0.38 in (9.7 mm) of rain and wind gusts up to 35 mph (55 km/h) across the islands.

Canada

On October 1, Environment Canada
Environment Canada
Environment Canada , legally incorporated as the Department of the Environment under the Department of the Environment Act Environment Canada (EC) (French: Environnement Canada), legally incorporated as the Department of the Environment under the Department of the Environment Act Environment...

 issued a tropical storm watch for the Avalon Peninsula
Avalon Peninsula
The Avalon Peninsula is a large peninsula that makes up the southeast portion of the island of Newfoundland.The peninsula is home to 257,223 people, which is approximately 51% of Newfoundland's population in 2009, and is the location of the provincial capital, St. John's. It is connected to the...

. Across Newfoundland, residents were warned of heavy rains that could accumulate to more than 4 in (101.6 mm). Striking the region just over a year after Hurricane Igor, Ophelia revealed that repairs made in the wake of the previous hurricane were inadequate. Six roads on the Burin
Burin Peninsula
The Burin Peninsula is a Canadian peninsula located on the south coast of the island of Newfoundland in the province of Newfoundland and Labrador....

 and Bonavista
Bonavista Peninsula
The Bonavista Peninsula is a large peninsula on the east coast of the island of Newfoundland in the Canadian province of Newfoundland and Labrador....

 Peninsulas were shut down during the storm, two of which sustained damage. Several culvert
Culvert
A culvert is a device used to channel water. It may be used to allow water to pass underneath a road, railway, or embankment. Culverts can be made of many different materials; steel, polyvinyl chloride and concrete are the most common...

s that were installed after Igor were again washed away by Ophelia.

British Isles

As Ophelia struck Newfoundland on October 3, forecasters in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 warned residents that the remnants of the storm would bring unsettled weather within a few days. In the midst of a record-breaking heat wave
Heat wave
A heat wave is a prolonged period of excessively hot weather, which may be accompanied by high humidity. There is no universal definition of a heat wave; the term is relative to the usual weather in the area...

, with temperatures reaching an all-time monthly record high of 86°F (29.9°C), the storm was expected to drastically reduce temperatures across the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 and Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

. Strong winds and heavy rains were also anticipated and there was a possibility of snow in the Scottish Highlands
Scottish Highlands
The Highlands is an historic region of Scotland. The area is sometimes referred to as the "Scottish Highlands". It was culturally distinguishable from the Lowlands from the later Middle Ages into the modern period, when Lowland Scots replaced Scottish Gaelic throughout most of the Lowlands...

.

See also



External links

  • National Hurricane Center
    National Hurricane Center
    The National Hurricane Center , located at Florida International University in Miami, Florida, is the division of the National Weather Service responsible for tracking and predicting weather systems within the tropics between the Prime Meridian and the 140th meridian west poleward to the 30th...

    's advisory archive
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