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:''For other storms of the same name, see Tropical Storm Betsy (disambiguation).'' Hurricane Betsy was an intense and destructive tropical cyclone that brought widespread damage to areas of Florida and the central United States Gulf Coast in September 1965. The storm's erratic nature, coupled with its intensity and minimized preparation time contributed to making Betsy the first tropical cyclone in the Atlantic basin to accrue at least $1 billion in damage. While the storm primarily affected areas of southern Florida and Louisiana, lesser effects were felt in The Bahamas and as far inland in the United States as the Ohio River Valley. Betsy began as a tropical depression north of French Guiana on August 27, and strengthened as it moved in a general northwestwardly direction. After executing a slight anticyclonic loop north of the Bahamas, Betsy proceeded to move through areas of South Florida on September 8, causing extensive crop damage. After emerging into the Gulf of Mexico, the cyclone strengthened and reached its peak intensity equivalent to that of a Category 4 hurricane on September 10 before making its final landfall near Grand Isle, Louisiana shortly thereafter. Once inland, Betsy was slow to weaken, and persisted for two more days before degenerating into an extratropical storm; these remnants lasted until September 13. As a developing tropical cyclone, Betsy tracked over the northern Leeward Islands, producing moderate gusts and slight rainfall, though only minimal damage was reported. After tracking over open waters for several days, Betsy had significantly strengthened upon moving through the Bahamas. There, considerable damage occurred, particularly to crops on the archipelago's islands. For the island chain, Betsy was considered the worst hurricane since a tropical cyclone impacted the region in 1929. Widespread power outage and property damage ensued due to the storm's strong winds. Overall, damage on the Bahamas amounted to at least $14 million, and one fatality occurred. From there Betsy tracked westward and made landfall on southern Florida, where it was considered the worst tropical cyclone since a hurricane in 1926. Betsy's strong storm surge inundated large portions of the Florida Keys, flooding streets and causing widespread damage. The only route out of the Keys onto the mainland was cut off by the storm. In the state alone, Betsy caused $139 million in damage and five deaths. Further inland, effects wrought by Betsy were considerably weaker, though precipitation caused by the storm extended as far northeast as Pennsylvania. Rainfall was primarily beneficial in Arkansas, though localized flooding impacted rice and cotton crops. In Kentucky and Illinois, strong winds caused moderate property damage. By the time the remnants of Betsy moved into the northeastern United States, the storm's winds and rainfall had substantially lessened, and as such resulting wind damage was negligible while precipitation benefited crops. In total, the damage wrought by Betsy throughout its existence equated to roughly $1.42 billion, making it the costliest Atlantic hurricane until it was surpassed by Hurricane Camille four years later. In addition the hurricane caused 81 deaths, primarily in Louisiana. After the season, the United States Weather Bureau retired the name Betsy from their rotating lists of tropical cyclone names. ==Meteorological history== The origins of Hurricane Betsy can be traced back to an area of disturbed weather southwest of Cape Verde that first identified via TIROS satellite imagery on August 23. Tracking westward, the tropical wave was intercepted by a United States Navy reconnaissance airplane early on August 27, which concluded that the disturbance had become a tropical cyclone of moderate intensity. Based on information from the flight, it was estimated that the system had organized into a tropical depression by 0000 UTC on August 27, east-southeast of Barbados.〔 Although operationally the United States Weather Bureau office in San Juan, Puerto Rico upgraded the disturbance to tropical storm intensity three hours after their first tropical cyclone bulletin that same day,〔〔 post-analysis indicated that the tropical depression had remained at the same intensity up until 1200 UTC on August 29. Nonetheless, the tropical cyclone was given the name Betsy for a period of time as a tropical depression,〔 contrary to typical tropical cyclone naming procedure. As Betsy approached the Windward Islands, it began to move in a more northwesterly direction,〔 and was briefly located in the Caribbean Sea during the overnight hours of August 28 before re-emerging into the Atlantic Ocean the following day,〔 after which Betsy was upgraded to tropical storm classification in post-analysis. Upon moving to the northwest of the Leeward Islands, Betsy entered conditions favorable for marked development. An upper-level trough centered a short distance north of the tropical storm enhanced outflow conditions and speed divergence.〔 Under these conditions, Betsy proceeded to quickly intensify,〔 and reconnaissance missions tasked by the United States Air Force and Weather Bureau indicated that the tropical storm had reached hurricane intensity by 0000 UTC on August 30,〔 centered roughly north-northeast of Puerto Rico. By coincidence, forecast responsibilities were transferred to the Weather Bureau Office in Miami, Florida at the same time;〔 however, the hurricane was still under the purview of the Weather Bureau per se.〔 Due to increasing atmospheric pressure heights to the north,〔 Betsy drastically slowed in forward speed and intensification,〔 and remained stationary for a period of time on August 31 before it began to drift westward. On September 2, Betsy began to quickly intensify, and after strengthening to a Category 3 hurricane-equivalent – a major hurricane on the modern-day Saffir–Simpson hurricane wind scale – the small hurricane attained Category 4 intensity and reached an initial peak intensity with winds of 140 mph (220 km/h) at 0000 UTC on September 4, while situated well north of the Turks and Caicos.〔 However, on September 5, a blocking ridge of high pressure situated over the Eastern United States forced Betsy to make a tight, clockwise loop and track in an unusual southwesterly path, redirecting it towards Florida and The Bahamas.〔〔 At roughly the same time, the hurricane weakened to Category 2 intensity, though it later restrengthened to Category 3 intensity on September 6. Betsy's atypical southwesterly path brought it directly over several islands in the northern Bahamas,〔 including Great Abaco Island. After stalling for a third time over portions of the central Bahamas, the major hurricane resumed its prior westward track towards South Florida.〔〔 Early on September 8, Betsy made landfall on Key Largo in extreme southeastern Florida with winds of 125 mph (205 km/h) and a minimum barometric pressure of 953 mbar (hPa; 28.15 inHg). Without much change in strength, the intense hurricane quickly traversed the Upper Keys and Florida Bay before emerging midday on September 8 into the Gulf of Mexico.〔 Situated in the warm waters of the Gulf of Mexico on September 8,〔 Betsy began to strengthen and accelerate towards the west and then northwest, under the influence of the same ridge of high pressure that had forced it southwestward three days prior.〔 At roughly the same time, hurricane forecast operations were handed over the Weather Bureau Office in New Orleans, Louisiana. During its trek through the gulf, Betsy accelerated to a maximum forward speed of 22 mph (35 km/h), a speed anomalously high for a tropical cyclone traversing the Gulf of Mexico.〔 At 0600 UTC on September 9, the hurricane was estimated to have regained Category 4 intensity, and continued to strengthen as it neared the Central United States Gulf Coast. At 0000 UTC the next day, Betsy reached its primary peak intensity with winds of 155 mph (250 km/h) and a minimum central pressure of 941 mbar (hPa; 27.79 inHg) shortly before moving ashore a rural area of Louisiana coastline adjacent to Houma and Grand Isle early on September 10.〔 Once inland, Betsy quickly weakened,〔 and paralleled the Mississippi River before degenerating into a tropical depression by 0600 UTC the following day. Afterwards, it began to track northeastward along the Ohio River before it transitioned into an extratropical cyclone on September 12. The remnant extratropical circulation of Betsy persisted into southern Ohio before dissipating entirely by 0000 UTC on September 13. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「:''For other storms of the same name, see Tropical Storm Betsy (disambiguation).'''''Hurricane Betsy''' was an intense and destructive tropical cyclone that brought widespread damage to areas of Florida and the central United States Gulf Coast in September 1965. The storm's erratic nature, coupled with its intensity and minimized preparation time contributed to making Betsy the first tropical cyclone in the Atlantic basin to accrue at least $1 billion in damage. While the storm primarily affected areas of southern Florida and Louisiana, lesser effects were felt in The Bahamas and as far inland in the United States as the Ohio River Valley. Betsy began as a tropical depression north of French Guiana on August 27, and strengthened as it moved in a general northwestwardly direction. After executing a slight anticyclonic loop north of the Bahamas, Betsy proceeded to move through areas of South Florida on September 8, causing extensive crop damage. After emerging into the Gulf of Mexico, the cyclone strengthened and reached its peak intensity equivalent to that of a Category 4 hurricane on September 10 before making its final landfall near Grand Isle, Louisiana shortly thereafter. Once inland, Betsy was slow to weaken, and persisted for two more days before degenerating into an extratropical storm; these remnants lasted until September 13.As a developing tropical cyclone, Betsy tracked over the northern Leeward Islands, producing moderate gusts and slight rainfall, though only minimal damage was reported. After tracking over open waters for several days, Betsy had significantly strengthened upon moving through the Bahamas. There, considerable damage occurred, particularly to crops on the archipelago's islands. For the island chain, Betsy was considered the worst hurricane since a tropical cyclone impacted the region in 1929. Widespread power outage and property damage ensued due to the storm's strong winds. Overall, damage on the Bahamas amounted to at least $14 million, and one fatality occurred. From there Betsy tracked westward and made landfall on southern Florida, where it was considered the worst tropical cyclone since a hurricane in 1926. Betsy's strong storm surge inundated large portions of the Florida Keys, flooding streets and causing widespread damage. The only route out of the Keys onto the mainland was cut off by the storm. In the state alone, Betsy caused $139 million in damage and five deaths.Further inland, effects wrought by Betsy were considerably weaker, though precipitation caused by the storm extended as far northeast as Pennsylvania. Rainfall was primarily beneficial in Arkansas, though localized flooding impacted rice and cotton crops. In Kentucky and Illinois, strong winds caused moderate property damage. By the time the remnants of Betsy moved into the northeastern United States, the storm's winds and rainfall had substantially lessened, and as such resulting wind damage was negligible while precipitation benefited crops. In total, the damage wrought by Betsy throughout its existence equated to roughly $1.42 billion, making it the costliest Atlantic hurricane until it was surpassed by Hurricane Camille four years later. In addition the hurricane caused 81 deaths, primarily in Louisiana. After the season, the United States Weather Bureau retired the name Betsy from their rotating lists of tropical cyclone names.==Meteorological history==The origins of Hurricane Betsy can be traced back to an area of disturbed weather southwest of Cape Verde that first identified via TIROS satellite imagery on August 23. Tracking westward, the tropical wave was intercepted by a United States Navy reconnaissance airplane early on August 27, which concluded that the disturbance had become a tropical cyclone of moderate intensity. Based on information from the flight, it was estimated that the system had organized into a tropical depression by 0000 UTC on August 27, east-southeast of Barbados. Although operationally the United States Weather Bureau office in San Juan, Puerto Rico upgraded the disturbance to tropical storm intensity three hours after their first tropical cyclone bulletin that same day, post-analysis indicated that the tropical depression had remained at the same intensity up until 1200 UTC on August 29. Nonetheless, the tropical cyclone was given the name Betsy for a period of time as a tropical depression, contrary to typical tropical cyclone naming procedure. As Betsy approached the Windward Islands, it began to move in a more northwesterly direction, and was briefly located in the Caribbean Sea during the overnight hours of August 28 before re-emerging into the Atlantic Ocean the following day, after which Betsy was upgraded to tropical storm classification in post-analysis.Upon moving to the northwest of the Leeward Islands, Betsy entered conditions favorable for marked development. An upper-level trough centered a short distance north of the tropical storm enhanced outflow conditions and speed divergence. Under these conditions, Betsy proceeded to quickly intensify, and reconnaissance missions tasked by the United States Air Force and Weather Bureau indicated that the tropical storm had reached hurricane intensity by 0000 UTC on August 30, centered roughly north-northeast of Puerto Rico. By coincidence, forecast responsibilities were transferred to the Weather Bureau Office in Miami, Florida at the same time; however, the hurricane was still under the purview of the Weather Bureau per se. Due to increasing atmospheric pressure heights to the north, Betsy drastically slowed in forward speed and intensification, and remained stationary for a period of time on August 31 before it began to drift westward. On September 2, Betsy began to quickly intensify, and after strengthening to a Category 3 hurricane-equivalent – a major hurricane on the modern-day Saffir–Simpson hurricane wind scale – the small hurricane attained Category 4 intensity and reached an initial peak intensity with winds of 140 mph (220 km/h) at 0000 UTC on September 4, while situated well north of the Turks and Caicos.However, on September 5, a blocking ridge of high pressure situated over the Eastern United States forced Betsy to make a tight, clockwise loop and track in an unusual southwesterly path, redirecting it towards Florida and The Bahamas. At roughly the same time, the hurricane weakened to Category 2 intensity, though it later restrengthened to Category 3 intensity on September 6. Betsy's atypical southwesterly path brought it directly over several islands in the northern Bahamas, including Great Abaco Island. After stalling for a third time over portions of the central Bahamas, the major hurricane resumed its prior westward track towards South Florida. Early on September 8, Betsy made landfall on Key Largo in extreme southeastern Florida with winds of 125 mph (205 km/h) and a minimum barometric pressure of 953 mbar (hPa; 28.15 inHg). Without much change in strength, the intense hurricane quickly traversed the Upper Keys and Florida Bay before emerging midday on September 8 into the Gulf of Mexico.Situated in the warm waters of the Gulf of Mexico on September 8, Betsy began to strengthen and accelerate towards the west and then northwest, under the influence of the same ridge of high pressure that had forced it southwestward three days prior. At roughly the same time, hurricane forecast operations were handed over the Weather Bureau Office in New Orleans, Louisiana. During its trek through the gulf, Betsy accelerated to a maximum forward speed of 22 mph (35 km/h), a speed anomalously high for a tropical cyclone traversing the Gulf of Mexico. At 0600 UTC on September 9, the hurricane was estimated to have regained Category 4 intensity, and continued to strengthen as it neared the Central United States Gulf Coast. At 0000 UTC the next day, Betsy reached its primary peak intensity with winds of 155 mph (250 km/h) and a minimum central pressure of 941 mbar (hPa; 27.79 inHg) shortly before moving ashore a rural area of Louisiana coastline adjacent to Houma and Grand Isle early on September 10. Once inland, Betsy quickly weakened, and paralleled the Mississippi River before degenerating into a tropical depression by 0600 UTC the following day. Afterwards, it began to track northeastward along the Ohio River before it transitioned into an extratropical cyclone on September 12. The remnant extratropical circulation of Betsy persisted into southern Ohio before dissipating entirely by 0000 UTC on September 13.」の詳細全文を読む :''For other storms of the same name, see Tropical Storm Betsy (disambiguation).'' Hurricane Betsy was an intense and destructive tropical cyclone that brought widespread damage to areas of Florida and the central United States Gulf Coast in September 1965. The storm's erratic nature, coupled with its intensity and minimized preparation time contributed to making Betsy the first tropical cyclone in the Atlantic basin to accrue at least $1 billion in damage. While the storm primarily affected areas of southern Florida and Louisiana, lesser effects were felt in The Bahamas and as far inland in the United States as the Ohio River Valley. Betsy began as a tropical depression north of French Guiana on August 27, and strengthened as it moved in a general northwestwardly direction. After executing a slight anticyclonic loop north of the Bahamas, Betsy proceeded to move through areas of South Florida on September 8, causing extensive crop damage. After emerging into the Gulf of Mexico, the cyclone strengthened and reached its peak intensity equivalent to that of a Category 4 hurricane on September 10 before making its final landfall near Grand Isle, Louisiana shortly thereafter. Once inland, Betsy was slow to weaken, and persisted for two more days before degenerating into an extratropical storm; these remnants lasted until September 13. As a developing tropical cyclone, Betsy tracked over the northern Leeward Islands, producing moderate gusts and slight rainfall, though only minimal damage was reported. After tracking over open waters for several days, Betsy had significantly strengthened upon moving through the Bahamas. There, considerable damage occurred, particularly to crops on the archipelago's islands. For the island chain, Betsy was considered the worst hurricane since a tropical cyclone impacted the region in 1929. Widespread power outage and property damage ensued due to the storm's strong winds. Overall, damage on the Bahamas amounted to at least $14 million, and one fatality occurred. From there Betsy tracked westward and made landfall on southern Florida, where it was considered the worst tropical cyclone since a hurricane in 1926. Betsy's strong storm surge inundated large portions of the Florida Keys, flooding streets and causing widespread damage. The only route out of the Keys onto the mainland was cut off by the storm. In the state alone, Betsy caused $139 million in damage and five deaths. Further inland, effects wrought by Betsy were considerably weaker, though precipitation caused by the storm extended as far northeast as Pennsylvania. Rainfall was primarily beneficial in Arkansas, though localized flooding impacted rice and cotton crops. In Kentucky and Illinois, strong winds caused moderate property damage. By the time the remnants of Betsy moved into the northeastern United States, the storm's winds and rainfall had substantially lessened, and as such resulting wind damage was negligible while precipitation benefited crops. In total, the damage wrought by Betsy throughout its existence equated to roughly $1.42 billion, making it the costliest Atlantic hurricane until it was surpassed by Hurricane Camille four years later. In addition the hurricane caused 81 deaths, primarily in Louisiana. After the season, the United States Weather Bureau retired the name Betsy from their rotating lists of tropical cyclone names. ==Meteorological history== The origins of Hurricane Betsy can be traced back to an area of disturbed weather southwest of Cape Verde that first identified via TIROS satellite imagery on August 23. Tracking westward, the tropical wave was intercepted by a United States Navy reconnaissance airplane early on August 27, which concluded that the disturbance had become a tropical cyclone of moderate intensity. Based on information from the flight, it was estimated that the system had organized into a tropical depression by 0000 UTC on August 27, east-southeast of Barbados.〔 Although operationally the United States Weather Bureau office in San Juan, Puerto Rico upgraded the disturbance to tropical storm intensity three hours after their first tropical cyclone bulletin that same day,〔〔 post-analysis indicated that the tropical depression had remained at the same intensity up until 1200 UTC on August 29. Nonetheless, the tropical cyclone was given the name Betsy for a period of time as a tropical depression,〔 contrary to typical tropical cyclone naming procedure. As Betsy approached the Windward Islands, it began to move in a more northwesterly direction,〔 and was briefly located in the Caribbean Sea during the overnight hours of August 28 before re-emerging into the Atlantic Ocean the following day,〔 after which Betsy was upgraded to tropical storm classification in post-analysis. Upon moving to the northwest of the Leeward Islands, Betsy entered conditions favorable for marked development. An upper-level trough centered a short distance north of the tropical storm enhanced outflow conditions and speed divergence.〔 Under these conditions, Betsy proceeded to quickly intensify,〔 and reconnaissance missions tasked by the United States Air Force and Weather Bureau indicated that the tropical storm had reached hurricane intensity by 0000 UTC on August 30,〔 centered roughly north-northeast of Puerto Rico. By coincidence, forecast responsibilities were transferred to the Weather Bureau Office in Miami, Florida at the same time;〔 however, the hurricane was still under the purview of the Weather Bureau per se.〔 Due to increasing atmospheric pressure heights to the north,〔 Betsy drastically slowed in forward speed and intensification,〔 and remained stationary for a period of time on August 31 before it began to drift westward. On September 2, Betsy began to quickly intensify, and after strengthening to a Category 3 hurricane-equivalent – a major hurricane on the modern-day Saffir–Simpson hurricane wind scale – the small hurricane attained Category 4 intensity and reached an initial peak intensity with winds of 140 mph (220 km/h) at 0000 UTC on September 4, while situated well north of the Turks and Caicos.〔 However, on September 5, a blocking ridge of high pressure situated over the Eastern United States forced Betsy to make a tight, clockwise loop and track in an unusual southwesterly path, redirecting it towards Florida and The Bahamas.〔〔 At roughly the same time, the hurricane weakened to Category 2 intensity, though it later restrengthened to Category 3 intensity on September 6. Betsy's atypical southwesterly path brought it directly over several islands in the northern Bahamas,〔 including Great Abaco Island. After stalling for a third time over portions of the central Bahamas, the major hurricane resumed its prior westward track towards South Florida.〔〔 Early on September 8, Betsy made landfall on Key Largo in extreme southeastern Florida with winds of 125 mph (205 km/h) and a minimum barometric pressure of 953 mbar (hPa; 28.15 inHg). Without much change in strength, the intense hurricane quickly traversed the Upper Keys and Florida Bay before emerging midday on September 8 into the Gulf of Mexico.〔 Situated in the warm waters of the Gulf of Mexico on September 8,〔 Betsy began to strengthen and accelerate towards the west and then northwest, under the influence of the same ridge of high pressure that had forced it southwestward three days prior.〔 At roughly the same time, hurricane forecast operations were handed over the Weather Bureau Office in New Orleans, Louisiana. During its trek through the gulf, Betsy accelerated to a maximum forward speed of 22 mph (35 km/h), a speed anomalously high for a tropical cyclone traversing the Gulf of Mexico.〔 At 0600 UTC on September 9, the hurricane was estimated to have regained Category 4 intensity, and continued to strengthen as it neared the Central United States Gulf Coast. At 0000 UTC the next day, Betsy reached its primary peak intensity with winds of 155 mph (250 km/h) and a minimum central pressure of 941 mbar (hPa; 27.79 inHg) shortly before moving ashore a rural area of Louisiana coastline adjacent to Houma and Grand Isle early on September 10.〔 Once inland, Betsy quickly weakened,〔 and paralleled the Mississippi River before degenerating into a tropical depression by 0600 UTC the following day. Afterwards, it began to track northeastward along the Ohio River before it transitioned into an extratropical cyclone on September 12. The remnant extratropical circulation of Betsy persisted into southern Ohio before dissipating entirely by 0000 UTC on September 13. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「:''For other storms of the same name, see Tropical Storm Betsy (disambiguation).''Hurricane Betsy''' was an intense and destructive tropical cyclone that brought widespread damage to areas of Florida and the central United States Gulf Coast in September 1965. The storm's erratic nature, coupled with its intensity and minimized preparation time contributed to making Betsy the first tropical cyclone in the Atlantic basin to accrue at least $1 billion in damage. While the storm primarily affected areas of southern Florida and Louisiana, lesser effects were felt in The Bahamas and as far inland in the United States as the Ohio River Valley. Betsy began as a tropical depression north of French Guiana on August 27, and strengthened as it moved in a general northwestwardly direction. After executing a slight anticyclonic loop north of the Bahamas, Betsy proceeded to move through areas of South Florida on September 8, causing extensive crop damage. After emerging into the Gulf of Mexico, the cyclone strengthened and reached its peak intensity equivalent to that of a Category 4 hurricane on September 10 before making its final landfall near Grand Isle, Louisiana shortly thereafter. Once inland, Betsy was slow to weaken, and persisted for two more days before degenerating into an extratropical storm; these remnants lasted until September 13.As a developing tropical cyclone, Betsy tracked over the northern Leeward Islands, producing moderate gusts and slight rainfall, though only minimal damage was reported. After tracking over open waters for several days, Betsy had significantly strengthened upon moving through the Bahamas. There, considerable damage occurred, particularly to crops on the archipelago's islands. For the island chain, Betsy was considered the worst hurricane since a tropical cyclone impacted the region in 1929. Widespread power outage and property damage ensued due to the storm's strong winds. Overall, damage on the Bahamas amounted to at least $14 million, and one fatality occurred. From there Betsy tracked westward and made landfall on southern Florida, where it was considered the worst tropical cyclone since a hurricane in 1926. Betsy's strong storm surge inundated large portions of the Florida Keys, flooding streets and causing widespread damage. The only route out of the Keys onto the mainland was cut off by the storm. In the state alone, Betsy caused $139 million in damage and five deaths.Further inland, effects wrought by Betsy were considerably weaker, though precipitation caused by the storm extended as far northeast as Pennsylvania. Rainfall was primarily beneficial in Arkansas, though localized flooding impacted rice and cotton crops. In Kentucky and Illinois, strong winds caused moderate property damage. By the time the remnants of Betsy moved into the northeastern United States, the storm's winds and rainfall had substantially lessened, and as such resulting wind damage was negligible while precipitation benefited crops. In total, the damage wrought by Betsy throughout its existence equated to roughly $1.42 billion, making it the costliest Atlantic hurricane until it was surpassed by Hurricane Camille four years later. In addition the hurricane caused 81 deaths, primarily in Louisiana. After the season, the United States Weather Bureau retired the name Betsy from their rotating lists of tropical cyclone names.==Meteorological history==The origins of Hurricane Betsy can be traced back to an area of disturbed weather southwest of Cape Verde that first identified via TIROS satellite imagery on August 23. Tracking westward, the tropical wave was intercepted by a United States Navy reconnaissance airplane early on August 27, which concluded that the disturbance had become a tropical cyclone of moderate intensity. Based on information from the flight, it was estimated that the system had organized into a tropical depression by 0000 UTC on August 27, east-southeast of Barbados. Although operationally the United States Weather Bureau office in San Juan, Puerto Rico upgraded the disturbance to tropical storm intensity three hours after their first tropical cyclone bulletin that same day, post-analysis indicated that the tropical depression had remained at the same intensity up until 1200 UTC on August 29. Nonetheless, the tropical cyclone was given the name Betsy for a period of time as a tropical depression, contrary to typical tropical cyclone naming procedure. As Betsy approached the Windward Islands, it began to move in a more northwesterly direction, and was briefly located in the Caribbean Sea during the overnight hours of August 28 before re-emerging into the Atlantic Ocean the following day, after which Betsy was upgraded to tropical storm classification in post-analysis.Upon moving to the northwest of the Leeward Islands, Betsy entered conditions favorable for marked development. An upper-level trough centered a short distance north of the tropical storm enhanced outflow conditions and speed divergence. Under these conditions, Betsy proceeded to quickly intensify, and reconnaissance missions tasked by the United States Air Force and Weather Bureau indicated that the tropical storm had reached hurricane intensity by 0000 UTC on August 30, centered roughly north-northeast of Puerto Rico. By coincidence, forecast responsibilities were transferred to the Weather Bureau Office in Miami, Florida at the same time; however, the hurricane was still under the purview of the Weather Bureau per se. Due to increasing atmospheric pressure heights to the north, Betsy drastically slowed in forward speed and intensification, and remained stationary for a period of time on August 31 before it began to drift westward. On September 2, Betsy began to quickly intensify, and after strengthening to a Category 3 hurricane-equivalent – a major hurricane on the modern-day Saffir–Simpson hurricane wind scale – the small hurricane attained Category 4 intensity and reached an initial peak intensity with winds of 140 mph (220 km/h) at 0000 UTC on September 4, while situated well north of the Turks and Caicos.However, on September 5, a blocking ridge of high pressure situated over the Eastern United States forced Betsy to make a tight, clockwise loop and track in an unusual southwesterly path, redirecting it towards Florida and The Bahamas. At roughly the same time, the hurricane weakened to Category 2 intensity, though it later restrengthened to Category 3 intensity on September 6. Betsy's atypical southwesterly path brought it directly over several islands in the northern Bahamas, including Great Abaco Island. After stalling for a third time over portions of the central Bahamas, the major hurricane resumed its prior westward track towards South Florida. Early on September 8, Betsy made landfall on Key Largo in extreme southeastern Florida with winds of 125 mph (205 km/h) and a minimum barometric pressure of 953 mbar (hPa; 28.15 inHg). Without much change in strength, the intense hurricane quickly traversed the Upper Keys and Florida Bay before emerging midday on September 8 into the Gulf of Mexico.Situated in the warm waters of the Gulf of Mexico on September 8, Betsy began to strengthen and accelerate towards the west and then northwest, under the influence of the same ridge of high pressure that had forced it southwestward three days prior. At roughly the same time, hurricane forecast operations were handed over the Weather Bureau Office in New Orleans, Louisiana. During its trek through the gulf, Betsy accelerated to a maximum forward speed of 22 mph (35 km/h), a speed anomalously high for a tropical cyclone traversing the Gulf of Mexico. At 0600 UTC on September 9, the hurricane was estimated to have regained Category 4 intensity, and continued to strengthen as it neared the Central United States Gulf Coast. At 0000 UTC the next day, Betsy reached its primary peak intensity with winds of 155 mph (250 km/h) and a minimum central pressure of 941 mbar (hPa; 27.79 inHg) shortly before moving ashore a rural area of Louisiana coastline adjacent to Houma and Grand Isle early on September 10. Once inland, Betsy quickly weakened, and paralleled the Mississippi River before degenerating into a tropical depression by 0600 UTC the following day. Afterwards, it began to track northeastward along the Ohio River before it transitioned into an extratropical cyclone on September 12. The remnant extratropical circulation of Betsy persisted into southern Ohio before dissipating entirely by 0000 UTC on September 13.」の詳細全文を読む ''Hurricane Betsy''' was an intense and destructive tropical cyclone that brought widespread damage to areas of Florida and the central United States Gulf Coast in September 1965. The storm's erratic nature, coupled with its intensity and minimized preparation time contributed to making Betsy the first tropical cyclone in the Atlantic basin to accrue at least $1 billion in damage. While the storm primarily affected areas of southern Florida and Louisiana, lesser effects were felt in The Bahamas and as far inland in the United States as the Ohio River Valley. Betsy began as a tropical depression north of French Guiana on August 27, and strengthened as it moved in a general northwestwardly direction. After executing a slight anticyclonic loop north of the Bahamas, Betsy proceeded to move through areas of South Florida on September 8, causing extensive crop damage. After emerging into the Gulf of Mexico, the cyclone strengthened and reached its peak intensity equivalent to that of a Category 4 hurricane on September 10 before making its final landfall near Grand Isle, Louisiana shortly thereafter. Once inland, Betsy was slow to weaken, and persisted for two more days before degenerating into an extratropical storm; these remnants lasted until September 13.As a developing tropical cyclone, Betsy tracked over the northern Leeward Islands, producing moderate gusts and slight rainfall, though only minimal damage was reported. After tracking over open waters for several days, Betsy had significantly strengthened upon moving through the Bahamas. There, considerable damage occurred, particularly to crops on the archipelago's islands. For the island chain, Betsy was considered the worst hurricane since a tropical cyclone impacted the region in 1929. Widespread power outage and property damage ensued due to the storm's strong winds. Overall, damage on the Bahamas amounted to at least $14 million, and one fatality occurred. From there Betsy tracked westward and made landfall on southern Florida, where it was considered the worst tropical cyclone since a hurricane in 1926. Betsy's strong storm surge inundated large portions of the Florida Keys, flooding streets and causing widespread damage. The only route out of the Keys onto the mainland was cut off by the storm. In the state alone, Betsy caused $139 million in damage and five deaths.Further inland, effects wrought by Betsy were considerably weaker, though precipitation caused by the storm extended as far northeast as Pennsylvania. Rainfall was primarily beneficial in Arkansas, though localized flooding impacted rice and cotton crops. In Kentucky and Illinois, strong winds caused moderate property damage. By the time the remnants of Betsy moved into the northeastern United States, the storm's winds and rainfall had substantially lessened, and as such resulting wind damage was negligible while precipitation benefited crops. In total, the damage wrought by Betsy throughout its existence equated to roughly $1.42 billion, making it the costliest Atlantic hurricane until it was surpassed by Hurricane Camille four years later. In addition the hurricane caused 81 deaths, primarily in Louisiana. After the season, the United States Weather Bureau retired the name Betsy from their rotating lists of tropical cyclone names.==Meteorological history==The origins of Hurricane Betsy can be traced back to an area of disturbed weather southwest of Cape Verde that first identified via TIROS satellite imagery on August 23. Tracking westward, the tropical wave was intercepted by a United States Navy reconnaissance airplane early on August 27, which concluded that the disturbance had become a tropical cyclone of moderate intensity. Based on information from the flight, it was estimated that the system had organized into a tropical depression by 0000 UTC on August 27, east-southeast of Barbados. Although operationally the United States Weather Bureau office in San Juan, Puerto Rico upgraded the disturbance to tropical storm intensity three hours after their first tropical cyclone bulletin that same day, post-analysis indicated that the tropical depression had remained at the same intensity up until 1200 UTC on August 29. Nonetheless, the tropical cyclone was given the name Betsy for a period of time as a tropical depression, contrary to typical tropical cyclone naming procedure. As Betsy approached the Windward Islands, it began to move in a more northwesterly direction, and was briefly located in the Caribbean Sea during the overnight hours of August 28 before re-emerging into the Atlantic Ocean the following day, after which Betsy was upgraded to tropical storm classification in post-analysis.Upon moving to the northwest of the Leeward Islands, Betsy entered conditions favorable for marked development. An upper-level trough centered a short distance north of the tropical storm enhanced outflow conditions and speed divergence. Under these conditions, Betsy proceeded to quickly intensify, and reconnaissance missions tasked by the United States Air Force and Weather Bureau indicated that the tropical storm had reached hurricane intensity by 0000 UTC on August 30, centered roughly north-northeast of Puerto Rico. By coincidence, forecast responsibilities were transferred to the Weather Bureau Office in Miami, Florida at the same time; however, the hurricane was still under the purview of the Weather Bureau per se. Due to increasing atmospheric pressure heights to the north, Betsy drastically slowed in forward speed and intensification, and remained stationary for a period of time on August 31 before it began to drift westward. On September 2, Betsy began to quickly intensify, and after strengthening to a Category 3 hurricane-equivalent – a major hurricane on the modern-day Saffir–Simpson hurricane wind scale – the small hurricane attained Category 4 intensity and reached an initial peak intensity with winds of 140 mph (220 km/h) at 0000 UTC on September 4, while situated well north of the Turks and Caicos.However, on September 5, a blocking ridge of high pressure situated over the Eastern United States forced Betsy to make a tight, clockwise loop and track in an unusual southwesterly path, redirecting it towards Florida and The Bahamas. At roughly the same time, the hurricane weakened to Category 2 intensity, though it later restrengthened to Category 3 intensity on September 6. Betsy's atypical southwesterly path brought it directly over several islands in the northern Bahamas, including Great Abaco Island. After stalling for a third time over portions of the central Bahamas, the major hurricane resumed its prior westward track towards South Florida. Early on September 8, Betsy made landfall on Key Largo in extreme southeastern Florida with winds of 125 mph (205 km/h) and a minimum barometric pressure of 953 mbar (hPa; 28.15 inHg). Without much change in strength, the intense hurricane quickly traversed the Upper Keys and Florida Bay before emerging midday on September 8 into the Gulf of Mexico.Situated in the warm waters of the Gulf of Mexico on September 8, Betsy began to strengthen and accelerate towards the west and then northwest, under the influence of the same ridge of high pressure that had forced it southwestward three days prior. At roughly the same time, hurricane forecast operations were handed over the Weather Bureau Office in New Orleans, Louisiana. During its trek through the gulf, Betsy accelerated to a maximum forward speed of 22 mph (35 km/h), a speed anomalously high for a tropical cyclone traversing the Gulf of Mexico. At 0600 UTC on September 9, the hurricane was estimated to have regained Category 4 intensity, and continued to strengthen as it neared the Central United States Gulf Coast. At 0000 UTC the next day, Betsy reached its primary peak intensity with winds of 155 mph (250 km/h) and a minimum central pressure of 941 mbar (hPa; 27.79 inHg) shortly before moving ashore a rural area of Louisiana coastline adjacent to Houma and Grand Isle early on September 10. Once inland, Betsy quickly weakened, and paralleled the Mississippi River before degenerating into a tropical depression by 0600 UTC the following day. Afterwards, it began to track northeastward along the Ohio River before it transitioned into an extratropical cyclone on September 12. The remnant extratropical circulation of Betsy persisted into southern Ohio before dissipating entirely by 0000 UTC on September 13.」の詳細全文を読む スポンサード リンク
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