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Hurricane Florence (2000)
Encyclopedia
Hurricane Florence was a Category 1 hurricane
on the Saffir-Simpson Hurricane Scale
that reached hurricane intensity three separate times. The tenth tropical cyclone and sixth named storm of the 2000 Atlantic hurricane season
, Florence developed on September 20 from a cold front
to the southwest of Bermuda
. Initially a subtropical cyclone
, it quickly organized, attaining hurricane status twice in a two day period before weakening while remaining nearly stationary. Florence accelerated northeastward, reaching peak winds as a hurricane after passing near Bermuda. On September 17, the storm was absorbed by a larger extratropical storm. Hurricane Florence threatened Bermuda
during its third time at hurricane intensity, bringing tropical storm force winds to the island but causing no reported damage. However, three deaths in North Carolina
were blamed on rip currents triggered by the hurricane on September 12.
moved off the East Coast of the United States
and stalled over the Atlantic Ocean
. By September 8, a weak frontal wave
began developing along the cold front. Late on September 9, convection
increased over the broad low pressure area
, and the overall system intensified beneath an upper-level low
. Subsequently, the system abandoned its frontal features as its appearance became more circular. With persistent but limited convection near and to the west of the center, the National Hurricane Center
(NHC) estimated the system developed into a subtropical
depression late on September 10 about 375 mi (604 km) west-southwest of Bermuda
; it was considered subtropical because the upper-circulation was believed to have been cold-core
. Operationally, advisories on the system were not initiated until 21 hours later.
Subsequent to developing, deep convection began developing and increasing around the center. On September 11, an Advanced Microwave Sounding Unit
temperature cross-section analysis indicated the system developed a warm thermal core
; as a result, it was re-classified as Tropical Depression Ten. Convection continued increasing, and it intensified to tropical storm status by 1200 UTC
. Operationally, it was considered a tropical depression, and significant strengthening was not expected. However, reports from Hurricane Hunters
confirmed the presence of tropical storm force winds, and as a result the National Hurricane Center named the cyclone Florence
. The storm continued quickly intensifying, and with the Hurricane Hunters reporting flight-level winds of over 85 mph (140 km/h), it was estimated Florence attained hurricane status late on September 11, or just six hours after the National Hurricane Center began issuing advisories on the storm. The strongest winds were confined to a very small area near the edge of the convection. Initially, the hurricane was tracking west-southwestward, steered by a mid-level ridge
to its northwest.
On September 12, the entrainment of drier air weakened Florence to tropical storm status. At the same time, its motion became nearly stationary as a ridge to its southeast weakened steering currents. An eye
developed in the center of the cyclone, and Florence again attained hurricane status late on September 12. Cooler water temperatures caused the hurricane to again weaken to tropical storm status on September 13. The next day, increased vertical wind shear
accelerated the weakening, leaving its cloud pattern disorganized. An approaching short-wave trough turned Florence to the east-southeast and later to the east-northeast as its forward motion increased. Convection increased near the center as the overall structure improved. Based on reports from the Hurricane Hunters, Florence was upgraded to hurricane status on September 16 about 200 mi(320 km) southwest of Bermuda. Later that day, the hurricane passed about 75 mi (120 km) northwest of Bermuda, its closest approach. Late on September 16, Florence reached peak winds of 80 mph (130 km/h) as an eyewall became apparent. Cooler waters weakened the hurricane to tropical storm status by September 17 as its motion accelerated further due to the approaching trough. Later that day, Florence was absorbed by the extratropical storm
associated with the trough about 80 mi (130 km) south of Cape Race
on the island of Newfoundland.
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Early in its duration, Hurricane Florence produced large swells that affected the East Coast of the United States. Rip currents caused three deaths due to drowning in North Carolina
, all in the southern portion of the state. Seven other people needed rescue, and at least two beaches were closed. On September 14, the government of Bermuda
issued a tropical storm watch
for the island; it was upgraded to a tropical storm warning the next day and later to a hurricane warning. The island reported sustained winds of 41 mph (67 km/h) with gusts to 58 mph (93 km/h). Rainfall at L.F. Wade International Airport accumulated to 0.47 in (12 mm). Later, the remnants of Florence produced heavy rainfall along the Avalon Peninsula
of Newfoundland, peaking at 2.26 in (57.5 mm).
Tropical cyclone
A tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones strengthen when water evaporated from the ocean is released as the saturated air rises, resulting in condensation of water vapor...
on the Saffir-Simpson Hurricane Scale
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...
that reached hurricane intensity three separate times. The tenth tropical cyclone and sixth named storm of the 2000 Atlantic hurricane season
2000 Atlantic hurricane season
The 2000 Atlantic hurricane season was the first season without a tropical cyclone in July since 1987. The season officially began on June 1, 2000, and lasted until November 30, 2000. The June through November dates conventionally delimit the period of each year when most tropical cyclones form in...
, Florence developed on September 20 from a cold front
Cold front
A cold front is defined as the leading edge of a cooler mass of air, replacing a warmer mass of air.-Development of cold front:The cooler and denser air wedges under the less-dense warmer air, lifting it...
to the southwest 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...
. Initially a subtropical cyclone
Subtropical cyclone
A subtropical cyclone is a weather system that has some characteristics of a tropical and an extratropical cyclone. As early as the 1950s, meteorologists were unclear whether they should be characterized as tropical or extratropical cyclones. They were officially recognized by the National...
, it quickly organized, attaining hurricane status twice in a two day period before weakening while remaining nearly stationary. Florence accelerated northeastward, reaching peak winds as a hurricane after passing near Bermuda. On September 17, the storm was absorbed by a larger extratropical storm. Hurricane Florence threatened 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...
during its third time at hurricane intensity, bringing tropical storm force winds to the island but causing no reported damage. However, three deaths in North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
were blamed on rip currents triggered by the hurricane on September 12.
Meteorological history
During the first week of September, a cold frontCold front
A cold front is defined as the leading edge of a cooler mass of air, replacing a warmer mass of air.-Development of cold front:The cooler and denser air wedges under the less-dense warmer air, lifting it...
moved off the East Coast of the United States
East Coast of the United States
The East Coast of the United States, also known as the Eastern Seaboard, refers to the easternmost coastal states in the United States, which touch the Atlantic Ocean and stretch up to Canada. The term includes the U.S...
and stalled over the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
. By September 8, a weak frontal wave
Trough (meteorology)
A trough is an elongated region of relatively low atmospheric pressure, often associated with fronts.Unlike fronts, there is not a universal symbol for a trough on a weather chart. The weather charts in some countries or regions mark troughs by a line. In the United States, a trough may be marked...
began developing along the cold front. Late on September 9, convection
Convection
Convection is the movement of molecules within fluids and rheids. It cannot take place in solids, since neither bulk current flows nor significant diffusion can take place in solids....
increased over the broad low pressure area
Low pressure area
A low-pressure area, or "low", is a region where the atmospheric pressure at sea level is below that of surrounding locations. Low-pressure systems form under areas of wind divergence which occur in upper levels of the troposphere. The formation process of a low-pressure area is known as...
, and the overall system intensified beneath an upper-level low
Cold-core low
A cold-core low, also known as a cold low or cold-core cyclone, is a cyclone aloft which has an associated cold pool of air residing at high altitude within the Earth's troposphere. It is a low pressure system which strengthens with height in accordance with the thermal wind relationship. These...
. Subsequently, the system abandoned its frontal features as its appearance became more circular. With persistent but limited convection near and to the west of the center, 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...
(NHC) estimated the system developed into a subtropical
Subtropical cyclone
A subtropical cyclone is a weather system that has some characteristics of a tropical and an extratropical cyclone. As early as the 1950s, meteorologists were unclear whether they should be characterized as tropical or extratropical cyclones. They were officially recognized by the National...
depression late on September 10 about 375 mi (604 km) west-southwest 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...
; it was considered subtropical because the upper-circulation was believed to have been cold-core
Extratropical cyclone
Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are a group of cyclones defined as synoptic scale low pressure weather systems that occur in the middle latitudes of the Earth having neither tropical nor polar characteristics, and are connected with fronts and...
. Operationally, advisories on the system were not initiated until 21 hours later.
Subsequent to developing, deep convection began developing and increasing around the center. On September 11, an Advanced Microwave Sounding Unit
Advanced Microwave Sounding Unit
The Advanced microwave sounding unit is a multi-channel microwave radiometer installed on meteorological satellites. The instrument examines several bands of microwave radiation from the atmosphere to perform atmospheric sounding of temperature and moisture levels.-Products:Level-1 radiance data...
temperature cross-section analysis indicated the system developed a warm thermal core
Tropical cyclone
A tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones strengthen when water evaporated from the ocean is released as the saturated air rises, resulting in condensation of water vapor...
; as a result, it was re-classified as Tropical Depression Ten. Convection continued increasing, and it intensified to tropical storm status by 1200 UTC
Coordinated Universal Time
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
. Operationally, it was considered a tropical depression, and significant strengthening was not expected. However, reports from Hurricane Hunters
Hurricane Hunters
The Hurricane Hunters are aircraft that fly into tropical cyclones in the North Atlantic Ocean and Northeastern Pacific Ocean for the specific purpose of directly measuring weather data in and around those storms. In the United States, the Air Force, Navy, and NOAA units have all participated in...
confirmed the presence of tropical storm force winds, and as a result the National Hurricane Center named the cyclone Florence
Florence (name)
Florence is an English, Italian or French given name for girls. It is derived from the Latin verb floreo, meaning "I flower", in the sense of a blossom...
. The storm continued quickly intensifying, and with the Hurricane Hunters reporting flight-level winds of over 85 mph (140 km/h), it was estimated Florence attained hurricane status late on September 11, or just six hours after the National Hurricane Center began issuing advisories on the storm. The strongest winds were confined to a very small area near the edge of the convection. Initially, the hurricane was tracking west-southwestward, steered by a mid-level ridge
Ridge (meteorology)
A ridge is an elongated region of relatively high atmospheric pressure, the opposite of a trough....
to its northwest.
On September 12, the entrainment of drier air weakened Florence to tropical storm status. At the same time, its motion became nearly stationary as a ridge to its southeast weakened steering currents. An eye
Eye (cyclone)
The eye is a region of mostly calm weather found at the center of strong tropical cyclones. The eye of a storm is a roughly circular area and typically 30–65 km in diameter. It is surrounded by the eyewall, a ring of towering thunderstorms where the second most severe weather of a cyclone...
developed in the center of the cyclone, and Florence again attained hurricane status late on September 12. Cooler water temperatures caused the hurricane to again weaken to tropical storm status on September 13. The next day, increased 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...
accelerated the weakening, leaving its cloud pattern disorganized. An approaching short-wave trough turned Florence to the east-southeast and later to the east-northeast as its forward motion increased. Convection increased near the center as the overall structure improved. Based on reports from the Hurricane Hunters, Florence was upgraded to hurricane status on September 16 about 200 mi(320 km) southwest of Bermuda. Later that day, the hurricane passed about 75 mi (120 km) northwest of Bermuda, its closest approach. Late on September 16, Florence reached peak winds of 80 mph (130 km/h) as an eyewall became apparent. Cooler waters weakened the hurricane to tropical storm status by September 17 as its motion accelerated further due to the approaching trough. Later that day, Florence was absorbed by the extratropical storm
Extratropical cyclone
Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are a group of cyclones defined as synoptic scale low pressure weather systems that occur in the middle latitudes of the Earth having neither tropical nor polar characteristics, and are connected with fronts and...
associated with the trough about 80 mi (130 km) south of Cape Race
Cape Race
Cape Race is a point of land located at the southeastern tip of the Avalon Peninsula on the island of Newfoundland, Canada. Its name is thought to come from the original Portuguese name for this cape, "Raso", or "bare"...
on the island of Newfoundland.
Impact and naming
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
, all in the southern portion of the state. Seven other people needed rescue, and at least two beaches were closed. On September 14, the government 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...
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 the island; it was upgraded to a tropical storm warning the next day and later to a hurricane warning. The island reported sustained winds of 41 mph (67 km/h) with gusts to 58 mph (93 km/h). Rainfall at L.F. Wade International Airport accumulated to 0.47 in (12 mm). Later, the remnants of Florence produced heavy rainfall along 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, peaking at 2.26 in (57.5 mm).
See also
- Other tropical cyclones named Florence
- List of North Carolina hurricanes (1980–present)
- Timeline of the 2000 Atlantic hurricane seasonTimeline of the 2000 Atlantic hurricane seasonThe Timeline of the 2000 Atlantic hurricane season documents all the storm formations, strengthening, weakening, landfalls, extratropical transitions, as well as dissipation...