Tropical Storm Gilda (1973)
Encyclopedia
Tropical Storm Gilda in 1973 was the first documented tropical cyclone
on record to transition into a subtropical cyclone
. It formed on October 16 in the western Caribbean Sea from a tropical wave
, and strengthened to reach peak winds of 70 mph (110 km/h) before striking Cuba. It later moved slowly through the Bahamas before weakening to tropical depression status. On October 24, with the assistance of a cold front off the coast of the eastern United States, Gilda transformed into a subtropical storm, becoming very large and strong. The storm later accelerated northeastward and became extratropical
, ultimately dissipating near Greenland.
The storm first brought heavy rainfall to Jamaica, causing six deaths and some damage from mudslides. While crossing Cuba and later the Bahamas, the storm caused little impact, limited to some crop damage. As a subtropical storm, Gilda brought gusty winds and high waves to much of the east coast of the United States, causing minor beach erosion and coastal property damage.
moved off the west coast of Africa on October 3. It tracked westward, reaching the Caribbean Sea on October 10. By October 13, a large area of convection persisted from Hispaniola southwestward through Panama, and over the next few days the convection organized and concentrated in the northwestern Caribbean Sea. An anticyclone
became established near Jamaica on October 15, which created a favorable upper-level environment for the system by reducing wind shear
. Around the same time, a low-level trough
emerged from the Intertropical Convergence Zone
, heading north off the coast of Nicaragua. Early on October 16, the system developed into a broad tropical depression about halfway between Central America and Jamaica.
The initial motion of the depression was uncertain, as steering currents could have resulted in a motion either to the west or to the north-northeast. With the possibility of the western track, the storm was remarked as being the first serious hurricane threat for southern Florida since Hurricane Gladys
in 1968. However, after formation the depression moved slowly north-northeastward. The thunderstorm activity gradually became better organized while rainbands increased around the circulation. By 0000 UTC
on October 18, the depression attained tropical storm status about 100 mi (160 km) northwest of the Cayman Islands, after which it was named Gilda by the National Hurricane Center
(NHC). The storm quickly strengthened as it moved toward southern Cuba, reaching peak winds of 70 mph (110 km/h) about 18 hours after reaching tropical storm status. Shortly thereafter, Gilda made landfall
near the border of the present day Cuban provinces
of Sancti Spíritus
and Ciego de Ávila
.
Tropical Storm Gilda weakened slightly over Cuba, crossing the island in less than twelve hours before emerging into the Atlantic Ocean early on October 19. At the time, the anticyclone over Jamaica which previously assisted the cyclone instead remained over the Caribbean, which increased shear over the storm. This caused the convection to gradually separate from the low-level circulation. Early on October 20, Gilda passed just southeast of Andros Island
in the Bahamas, around the same time that the Hurricane Hunters
recorded an atmospheric pressure
of 994 mbar
; this was the lowest recorded pressure in association with Gilda while it was a tropical cyclone. It gradually weakened due to the wind shear, resulting in the low-level steering currents becoming dominant. After moving through the Exuma
island chain, the storm passed near or over Eleuthera
, and late on October 21 Gilda became nearly stationary about 60 mi (95 km/h) east of Harbour Island. Late on October 22, after moving only about 6 mi (10 km) in a 24 hour period, Gilda weakened to a tropical depression.
Now a tropical depression, Gilda remained nearly stationary for another 24 hours before accelerating northeastward, under the influence of an upper-level trough exiting the east coast of the United States. Cold air from the trough interacted with Gilda, providing a baroclinic
environment for intensifying, and on October 24 the storm transitioned into a subtropical storm
about halfway between Hispaniola and North Carolina. This made Gilda the first tropical storm on record to transition into a subtropical cyclone. Operationally, tropical storm advisories were still issued on Gilda while it was subtropical, due to the need to maintain consistency and the possibility it could again become tropical. The circulation of the storm became very large, at one point stretching from New England to the Bahamas, and eastward beyond Bermuda, or a diameter of more than 1300 mi (2100 km). On October 25, Gilda passed about halfway between Bermuda and Cape Hatteras
, when it reached peak winds of 70 mph (110 km/h). Subsequently it turned northeastward, and on October 27 attained a minimum pressure of 984 mbar, the lowest of its duration while tropical or subtropical. Later that day, Gilda became an extratropical cyclone
southeast of the Canadian Maritimes as it moved over colder waters. After passing just southeast of Newfoundland, the storm continued northeastward, becoming nearly stationary off the coast of Greenland before dissipating on October 30.
where six houses were destroyed. Elsewhere on the island, the mudslides caused further property damage and left some roads unpassable. Six people were killed throughout the country. The storm did not have significant impact in Cuba. A station in the mountains of what was then known as Oriente Province recorded winds of 60 mph (95 km/h). The city of Morón
, located along the northern coast of Cuba, recorded 6.13 inches (155 mm) of rainfall in the 6 hour period prior to the storm passing the area. Damage was minor, limited to some crop damage in the eastern portion of the island, as well as power outages. The threat of the storm forced several thousand people to leave their homes.
In the Bahamas, officials closed schools, and many businesses closed early on the day the storm moved through the country. The storm's stationary motion caused several days of high tides and heavy rains. Tropical storm force wind gusts were reported on Andros Island, and gusts peaked at 75 mph (120 km/h) on Golden Cay. Gilda's passage left crop damage on several islands, although monetary losses in the country were minor.
When Gilda was forecast to move near southeastern Florida, gale warning
s were issued from North Key Largo
to Fort Lauderdale
. Rough seas affected the Florida coastline for about 72 hours, causing moderate coastal property damage and beach erosion. After becoming a large subtropical cyclone, gale warnings were issued at various times from Cape Hatteras
, North Carolina to the mouth of the Merrimack River
in Massachusetts. High surf and minor beach erosion were reported along the coastline, and gale force winds were observed from North Carolina to New Jersey. Over the western Atlantic Ocean, the storm produced strong winds and rough seas. One ship reported a wave height of 28 ft (8.5 m), though no significant marine losses were reported. Around the time of it becoming extratropical, Sable Island
off the coast of Nova Scotia recorded a wind gust of 74 mph (119 km/h).
Tropical Storm Gilda was notable as being the first observed tropical cyclone to transition into a subtropical cyclone; several subtropical cyclones have undergone tropical cyclogenesis
, but never the opposite. Since Gilda, a few other storms accomplished the feat. In 1980, a tropical depression dissipated, reformed as a subtropical depression, and later became Hurricane Georges over the open Atlantic Ocean. The next year, Tropical Storm Jose became subtropical near the end of its duration, and in 1984, Hurricane Klaus
became a subtropical storm over the western Atlantic Ocean. In 2001, Tropical Storm Allison
, after causing devastating flooding in Texas, became a subtropical storm over the Gulf of Mexico and moved across much of the southeastern United States.
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 record to transition into 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 formed on October 16 in the western Caribbean Sea from 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...
, and strengthened to reach peak winds of 70 mph (110 km/h) before striking Cuba. It later moved slowly through the Bahamas before weakening to tropical depression status. On October 24, with the assistance of a cold front off the coast of the eastern United States, Gilda transformed into a subtropical storm, becoming very large and strong. The storm later accelerated northeastward and became extratropical
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...
, ultimately dissipating near Greenland.
The storm first brought heavy rainfall to Jamaica, causing six deaths and some damage from mudslides. While crossing Cuba and later the Bahamas, the storm caused little impact, limited to some crop damage. As a subtropical storm, Gilda brought gusty winds and high waves to much of the east coast of the United States, causing minor beach erosion and coastal property damage.
Storm history
A tropical waveTropical 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...
moved off the west coast of Africa on October 3. It tracked westward, reaching the Caribbean Sea on October 10. By October 13, a large area of convection persisted from Hispaniola southwestward through Panama, and over the next few days the convection organized and concentrated in the northwestern Caribbean Sea. An anticyclone
Anticyclone
An anticyclone is a weather phenomenon defined by the United States' National Weather Service's glossary as "[a] large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere, counterclockwise in the Southern Hemisphere"...
became established near Jamaica on October 15, which created a favorable upper-level environment for the system by reducing 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...
. Around the same time, a low-level trough
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...
emerged from the Intertropical Convergence Zone
Intertropical Convergence Zone
The Intertropical Convergence Zone , known by sailors as The Doldrums, is the area encircling the earth near the equator where winds originating in the northern and southern hemispheres come together....
, heading north off the coast of Nicaragua. Early on October 16, the system developed into a broad tropical depression about halfway between Central America and Jamaica.
The initial motion of the depression was uncertain, as steering currents could have resulted in a motion either to the west or to the north-northeast. With the possibility of the western track, the storm was remarked as being the first serious hurricane threat for southern Florida since Hurricane Gladys
Hurricane Gladys (1968)
Hurricane Gladys was the most destructive hurricane in the 1968 Atlantic hurricane season, causing over $100 million in damage and ten deaths. The last storm of the season, it caused heavy rainfall along its path through the Western Caribbean Sea, Florida, and up through Atlantic Canada...
in 1968. However, after formation the depression moved slowly north-northeastward. The thunderstorm activity gradually became better organized while rainbands increased around the circulation. By 0000 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...
on October 18, the depression attained tropical storm status about 100 mi (160 km) northwest of the Cayman Islands, after which it was named Gilda by 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). The storm quickly strengthened as it moved toward southern Cuba, reaching peak winds of 70 mph (110 km/h) about 18 hours after reaching tropical storm status. Shortly thereafter, Gilda made landfall
Landfall (meteorology)
Landfall is the event of a tropical cyclone or a waterspout coming onto land after being over water. When a waterspout makes landfall it is reclassified as a tornado, which can then cause damage inland...
near the border of the present day Cuban provinces
Provinces of Cuba
Administratively, Cuba is divided into 15 provinces and one special municipality not included in any province. The last modification was approved in August 2010 , splitting Havana province into two new provinces: Artemisa and Mayabeque...
of Sancti Spíritus
Sancti Spíritus Province
Sancti Spíritus is one of the provinces of Cuba. Its capital is the identically named Sancti Spíritus. Another major city is Trinidad.The southern coast of the province is flat, but the western portion of Sancti Spíritus province is mountainous. The southeast has numerous mangroves and swamps...
and Ciego de Ávila
Ciego de Ávila Province
Ciego de Ávila is one of the provinces of Cuba, and was previously part of Camagüey Province. Its capital is Ciego de Ávila, which lies on the Carretera Central , and the second city is Morón, further north....
.
Tropical Storm Gilda weakened slightly over Cuba, crossing the island in less than twelve hours before emerging into the Atlantic Ocean early on October 19. At the time, the anticyclone over Jamaica which previously assisted the cyclone instead remained over the Caribbean, which increased shear over the storm. This caused the convection to gradually separate from the low-level circulation. Early on October 20, Gilda passed just southeast of Andros Island
Andros, Bahamas
Andros Island is an archipelago within the archipelago-nation of the Bahamas, the largest of the 26 inhabited Bahamian Islands. Geo-politically considered a single island, Andros has an area greater than all the other 700 Bahamian islands combined...
in the Bahamas, around the same time that the 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...
recorded an atmospheric pressure
Atmospheric pressure
Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...
of 994 mbar
Bar (unit)
The bar is a unit of pressure equal to 100 kilopascals, and roughly equal to the atmospheric pressure on Earth at sea level. Other units derived from the bar are the megabar , kilobar , decibar , centibar , and millibar...
; this was the lowest recorded pressure in association with Gilda while it was a tropical cyclone. It gradually weakened due to the wind shear, resulting in the low-level steering currents becoming dominant. After moving through the Exuma
Exuma
Exuma is a district of the Bahamas, consisting of over 360 islands . The largest of the cays is Great Exuma, which is 37 mi in length and joined to another island, Little Exuma by a small bridge. The capital and largest city in the district is George Town , founded 1793 and located on Great...
island chain, the storm passed near or over Eleuthera
Eleuthera
Eleuthera is an island in The Bahamas, lying 50 miles east of Nassau. It is very long and thin—110 miles long and in places little more than a mile wide. According to the 2000 Census, the population of Eleuthera is approximately 8,000...
, and late on October 21 Gilda became nearly stationary about 60 mi (95 km/h) east of Harbour Island. Late on October 22, after moving only about 6 mi (10 km) in a 24 hour period, Gilda weakened to a tropical depression.
Now a tropical depression, Gilda remained nearly stationary for another 24 hours before accelerating northeastward, under the influence of an upper-level trough exiting the east coast of the United States. Cold air from the trough interacted with Gilda, providing a baroclinic
Baroclinity
In fluid dynamics, the baroclinity of a stratified fluid is a measure of how misaligned the gradient of pressure is from the gradient of density in a fluid...
environment for intensifying, and on October 24 the storm transitioned into a subtropical storm
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...
about halfway between Hispaniola and North Carolina. This made Gilda the first tropical storm on record to transition into a subtropical cyclone. Operationally, tropical storm advisories were still issued on Gilda while it was subtropical, due to the need to maintain consistency and the possibility it could again become tropical. The circulation of the storm became very large, at one point stretching from New England to the Bahamas, and eastward beyond Bermuda, or a diameter of more than 1300 mi (2100 km). On October 25, Gilda passed about halfway between Bermuda and Cape Hatteras
Cape Hatteras
Cape Hatteras is a cape on the coast of North Carolina. It is the point that protrudes the farthest to the southeast along the northeast-to-southwest line of the Atlantic coast of North America...
, when it reached peak winds of 70 mph (110 km/h). Subsequently it turned northeastward, and on October 27 attained a minimum pressure of 984 mbar, the lowest of its duration while tropical or subtropical. Later that day, Gilda became an extratropical cyclone
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...
southeast of the Canadian Maritimes as it moved over colder waters. After passing just southeast of Newfoundland, the storm continued northeastward, becoming nearly stationary off the coast of Greenland before dissipating on October 30.
Preparations, impact, and records
Tropical Storm Gilda first affected Jamaica, bringing heavy rainfall in a three day period. The rains produced landslides, particularly in Saint Andrew ParishSaint Andrew Parish, Jamaica
Saint Andrew is a parish, situated in the southeast of Jamaica in the county of Surrey. It lies north, west and east of Kingston, and stretches into the Blue Mountains and at the 2001 census had the highest population of all the parishes in Jamaica. The Right Excellent George William Gordon Saint...
where six houses were destroyed. Elsewhere on the island, the mudslides caused further property damage and left some roads unpassable. Six people were killed throughout the country. The storm did not have significant impact in Cuba. A station in the mountains of what was then known as Oriente Province recorded winds of 60 mph (95 km/h). The city of Morón
Morón, Cuba
Morón is one of ten municipalities in province Ciego de Ávila in central Cuba. It is the second in importance and the oldest. Morón is the closest city to the tourist resorts on Cayo Coco and Cayo Guillermo.- Geography :...
, located along the northern coast of Cuba, recorded 6.13 inches (155 mm) of rainfall in the 6 hour period prior to the storm passing the area. Damage was minor, limited to some crop damage in the eastern portion of the island, as well as power outages. The threat of the storm forced several thousand people to leave their homes.
In the Bahamas, officials closed schools, and many businesses closed early on the day the storm moved through the country. The storm's stationary motion caused several days of high tides and heavy rains. Tropical storm force wind gusts were reported on Andros Island, and gusts peaked at 75 mph (120 km/h) on Golden Cay. Gilda's passage left crop damage on several islands, although monetary losses in the country were minor.
When Gilda was forecast to move near southeastern Florida, gale warning
Gale warning
A gale warning is a warning issued by weather services in maritime locations about the existence of winds of gale force or above or the imminent occurrence of gales at sea...
s were issued from North Key Largo
North Key Largo, Florida
North Key Largo is a census-designated place in Monroe County, Florida, United States. The population was 1,049 at the 2000 census.-Geography:North Key Largo is located at ....
to Fort Lauderdale
Fort Lauderdale, Florida
Fort Lauderdale is a city in the U.S. state of Florida, on the Atlantic coast. It is the county seat of Broward County. As of the 2010 census, the city had a population of 165,521. It is a principal city of the South Florida metropolitan area, which was home to 5,564,635 people at the 2010...
. Rough seas affected the Florida coastline for about 72 hours, causing moderate coastal property damage and beach erosion. After becoming a large subtropical cyclone, gale warnings were issued at various times from Cape Hatteras
Cape Hatteras
Cape Hatteras is a cape on the coast of North Carolina. It is the point that protrudes the farthest to the southeast along the northeast-to-southwest line of the Atlantic coast of North America...
, North Carolina to the mouth of the Merrimack River
Merrimack River
The Merrimack River is a river in the northeastern United States. It rises at the confluence of the Pemigewasset and Winnipesaukee rivers in Franklin, New Hampshire, flows southward into Massachusetts, and then flows northeast until it empties into the Atlantic Ocean at Newburyport...
in Massachusetts. High surf and minor beach erosion were reported along the coastline, and gale force winds were observed from North Carolina to New Jersey. Over the western Atlantic Ocean, the storm produced strong winds and rough seas. One ship reported a wave height of 28 ft (8.5 m), though no significant marine losses were reported. Around the time of it becoming extratropical, Sable Island
Sable Island
Sable Island is a small Canadian island situated 300 km southeast of mainland Nova Scotia in the Atlantic Ocean. The island is a year-round home to approximately five people...
off the coast of Nova Scotia recorded a wind gust of 74 mph (119 km/h).
Tropical Storm Gilda was notable as being the first observed tropical cyclone to transition into a subtropical cyclone; several subtropical cyclones have undergone tropical cyclogenesis
Tropical cyclogenesis
Tropical cyclogenesis is the term that describes the development and strengthening of a tropical cyclone in the atmosphere. The mechanisms through which tropical cyclogenesis occurs are distinctly different from those through which mid-latitude cyclogenesis occurs...
, but never the opposite. Since Gilda, a few other storms accomplished the feat. In 1980, a tropical depression dissipated, reformed as a subtropical depression, and later became Hurricane Georges over the open Atlantic Ocean. The next year, Tropical Storm Jose became subtropical near the end of its duration, and in 1984, Hurricane Klaus
Hurricane Klaus (1984)
Hurricane Klaus was an Atlantic hurricane that hit the Leeward Islands from the west in November of the 1984 Atlantic hurricane season. Forming from a broad area of low pressure on November 5, Klaus maintained a northeast movement throughout much of its path...
became a subtropical storm over the western Atlantic Ocean. In 2001, Tropical Storm Allison
Tropical Storm Allison
Tropical Storm Allison was a tropical storm that devastated southeast Texas in June of the 2001 Atlantic hurricane season. The first storm of the season, Allison lasted an unusually long period of time for a June storm, remaining tropical or subtropical for 15 days...
, after causing devastating flooding in Texas, became a subtropical storm over the Gulf of Mexico and moved across much of the southeastern United States.
See also
- Other tropical cyclones named Gilda