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1991 Perfect Storm
The 1991 Perfect Storm, also known as The No-Name Storm (especially in the years immediately after it took place) and the Halloween Gale/Storm, was a damaging and deadly nor'easter (i.e., extratropical cyclone impacting the Atlantic Provinces of Canada) in October 1991. While initially an extratropical cyclone, it absorbed Hurricane Grace to its south, later evolving into a small, unnamed Category 1 hurricane. The storm lashed the East coast of the United States with high waves and coastal flooding during its extratropical cyclone phase. Damage from the storm totaled over $200 million (1991 USD) and resulted in thirteen fatalities, six of them from the sinking of the Andrea Gail, which later inspired the book and movie The Perfect Storm. The nor'easter received its name, playing off the common expression, after a conversation between Boston National Weather Service forecaster Robert Case and author Sebastian Junger.
The initial area of low pressure developed off the coast of Atlantic Canada on October 28. Forced southward by a ridge to its north, it reached its peak intensity as a large and powerful extratropical cyclone. Moving over warmer waters, the system transitioned into a subtropical cyclone and subsequently into a tropical storm. It then executed a counter-clockwise loop off the Mid-Atlantic states and turned toward the Northeast. On November 1, the system evolved into a Category 1 hurricane, with peak sustained winds of 75 miles per hour (120 km/h). The National Hurricane Center left it unnamed in order to avoid public confusion, since the storm was already widely reported in its earlier, extratropical phase. The tropical system weakened, striking Nova Scotia as a tropical storm before dissipating. The system was the twelfth and final tropical cyclone, the eighth tropical storm, and fourth hurricane in the 1991 Atlantic hurricane season.
Most of the damage occurred while the storm was extratropical, after waves up to 30 feet (10 m) struck the coastline from Nova Scotia to Florida and southeastward to Puerto Rico. In portions of New England, the damage was worse than that caused by Hurricane Bob two months earlier. Aside from tidal flooding along rivers, the storm's effects were primarily concentrated along the coast. A buoy off the coast of Nova Scotia reported a wave height of 100.7 feet (30.7 m), the highest ever recorded in the province's offshore waters. In Massachusetts, where damage was heaviest, over 100 homes were destroyed or severely damaged. To the north, in Maine, more than 100 homes were affected, including the vacation home of then-President George H. W. Bush. More than 38,000 people were left without power and, along the coast, high waves inundated roads and buildings. Off the shore of New York's Long Island, an Air National Guard helicopter ran out of fuel and crashed; four members of its crew were rescued and one died. Two people died after their boat sank off Staten Island. High waves swept two people to their deaths, one in Rhode Island and one in Puerto Rico, and another person was blown off a bridge to his death. The tropical storm that formed late in the system's duration caused little impact, limited to power outages and slick roads; one person was killed in Newfoundland from a traffic accident related to the storm.
A volcanic winter is thought to have started with the 1991 eruption of Mount Pinatubo. The large quantities of ash and sulfur dioxide it released into the stratosphere formed an aerosol layer that blocked sunlight from reaching the Earth's surface and reflected solar radiation back into space. This caused global temperatures to drop by up to 0.5 - 0.6 °C (0.9 - 1.1 °F) from 1991 to 1993. Some meteorologists speculate that the altered jet stream and cooler sea surface temperatures, possibly influenced by Pinatubo's aerosols, may have contributed to the storm's unusual development and strength.
The Perfect Storm originated from a cold front that exited the East coast of the United States. On October 28, the front spawned an extratropical low to the east of Nova Scotia. At the same time, a ridge extended from the Appalachian Mountains northeastward to Greenland, anchored by a strong high-pressure center over eastern Canada. The blocking ridge forced the developing extratropical low, which would normally have moved northeastward, to track southeastward and then westward in a rare retrograde motion, initiating a set of meteorological circumstances estimated to occur only once every 50 to 100 years (most nor'easters track northeastward, but this storm instead turned southwestward). On October 29, Hurricane Grace, a tropical system that had developed separately in the western Atlantic and that was moving northward, was swept into the warm conveyor belt of the deepening cyclone. By the next day, October 30, Grace was completely absorbed. The merger enhanced the intensity of the nor'easter, fueled by the sharp temperature contrast between cold air to the northwest and the warm, moist air from Grace's remnants.
At approximately 12:00 UTC on October 30, while situated about 390 miles (630 km) south of Halifax, Nova Scotia, the nor'easter reached peak intensity, with a central pressure of 972 mbar and winds of up to 70 mph (110 km/h). The strong pressure gradient between the storm and the blocking high to the north produced damaging winds and very large waves. Between the southern New England coast and the center of the storm, the pressure differential was 70 mbar (2.1 inHg). A buoy 264 miles (425 km) south of Halifax, Nova Scotia, recorded a wave height of 100.7 feet (30.7 m), the highest ever measured on the Scotian Shelf, the oceanic shelf off the coast of Nova Scotia. East of Cape Cod, at approximately 15:00 UTC on October 30, a NOAA buoy located at 41°06′N 66°36′W / 41.1°N 66.6°W recorded maximum sustained winds of 56 mph (90 km/h) with gusts to 75 mph (121 km/h), and a significant wave height (average height of the highest one-third of all waves) of 39 feet (12 m). Another buoy, located at 40°30′N 69°30′W / 40.5°N 69.5°W, recorded maximum sustained winds of 61 mph (98 km/h) with gusts to 72 mph (116 km/h) and a significant wave height of 31 feet (9.4 m) at approximately 00:00 UTC on October 31.
Upon peaking in intensity, the nor'easter turned southward and gradually weakened. By November 1, its pressure had risen to 998 millibars (29.5 inHg). The low moved over warm waters of the Gulf Stream, where bands of convection around the center began to organize. Around this time, the system attained subtropical characteristics. While the storm was moving in a counter-clockwise loop, a tropical cyclone had been identified at the center of the larger low (these conditions, although rare, had been observed: during 1980, Hurricane Karl formed within a larger non-tropical weather system). By approximately 14:00 UTC on November 1, an eye feature was forming, and the tropical cyclone reached its peak intensity with maximum sustained winds of 75 mph (121 km/h); these estimates, combined with reports from an Air Force Reserve Unit flight into the storm and confirmation that a warm-core center was present, indicated that the system had become a Category 1 hurricane on the Saffir–Simpson Hurricane Scale. The hurricane accelerated toward the northeast and quickly weakened back into a tropical storm. It made landfall near Halifax, Nova Scotia, at 14:00 UTC on November 2, with sustained winds of 45 mph (72 km/h). While the storm was approaching the coast, weather radars depicted curved rainbands on the western side of the system. After crossing over Prince Edward Island, the storm fully dissipated late on November 2.
For several days, weather models forecast the development of a significant storm off New England. However, the models were inadequate in forecasting coastal conditions, which in one instance failed to provide adequate warning. In addition, a post-storm assessment found an insufficient number of observation sites along the coast. On October 27, the Ocean Prediction Center noted that a "dangerous storm" would form within 36 hours, with its wording emphasizing the unusual nature of the storm. The National Weather Service likewise issued warnings for the potential storm, providing information to emergency service offices as well as the media. The public, however, was skeptical and did not recognize the threat. The timely warnings ultimately lowered the death toll; whereas the Perfect Storm caused 13 deaths, the blizzard of 1978 killed 99 people, and the 1938 New England hurricane killed 564 people.
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1991 Perfect Storm AI simulator
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1991 Perfect Storm
The 1991 Perfect Storm, also known as The No-Name Storm (especially in the years immediately after it took place) and the Halloween Gale/Storm, was a damaging and deadly nor'easter (i.e., extratropical cyclone impacting the Atlantic Provinces of Canada) in October 1991. While initially an extratropical cyclone, it absorbed Hurricane Grace to its south, later evolving into a small, unnamed Category 1 hurricane. The storm lashed the East coast of the United States with high waves and coastal flooding during its extratropical cyclone phase. Damage from the storm totaled over $200 million (1991 USD) and resulted in thirteen fatalities, six of them from the sinking of the Andrea Gail, which later inspired the book and movie The Perfect Storm. The nor'easter received its name, playing off the common expression, after a conversation between Boston National Weather Service forecaster Robert Case and author Sebastian Junger.
The initial area of low pressure developed off the coast of Atlantic Canada on October 28. Forced southward by a ridge to its north, it reached its peak intensity as a large and powerful extratropical cyclone. Moving over warmer waters, the system transitioned into a subtropical cyclone and subsequently into a tropical storm. It then executed a counter-clockwise loop off the Mid-Atlantic states and turned toward the Northeast. On November 1, the system evolved into a Category 1 hurricane, with peak sustained winds of 75 miles per hour (120 km/h). The National Hurricane Center left it unnamed in order to avoid public confusion, since the storm was already widely reported in its earlier, extratropical phase. The tropical system weakened, striking Nova Scotia as a tropical storm before dissipating. The system was the twelfth and final tropical cyclone, the eighth tropical storm, and fourth hurricane in the 1991 Atlantic hurricane season.
Most of the damage occurred while the storm was extratropical, after waves up to 30 feet (10 m) struck the coastline from Nova Scotia to Florida and southeastward to Puerto Rico. In portions of New England, the damage was worse than that caused by Hurricane Bob two months earlier. Aside from tidal flooding along rivers, the storm's effects were primarily concentrated along the coast. A buoy off the coast of Nova Scotia reported a wave height of 100.7 feet (30.7 m), the highest ever recorded in the province's offshore waters. In Massachusetts, where damage was heaviest, over 100 homes were destroyed or severely damaged. To the north, in Maine, more than 100 homes were affected, including the vacation home of then-President George H. W. Bush. More than 38,000 people were left without power and, along the coast, high waves inundated roads and buildings. Off the shore of New York's Long Island, an Air National Guard helicopter ran out of fuel and crashed; four members of its crew were rescued and one died. Two people died after their boat sank off Staten Island. High waves swept two people to their deaths, one in Rhode Island and one in Puerto Rico, and another person was blown off a bridge to his death. The tropical storm that formed late in the system's duration caused little impact, limited to power outages and slick roads; one person was killed in Newfoundland from a traffic accident related to the storm.
A volcanic winter is thought to have started with the 1991 eruption of Mount Pinatubo. The large quantities of ash and sulfur dioxide it released into the stratosphere formed an aerosol layer that blocked sunlight from reaching the Earth's surface and reflected solar radiation back into space. This caused global temperatures to drop by up to 0.5 - 0.6 °C (0.9 - 1.1 °F) from 1991 to 1993. Some meteorologists speculate that the altered jet stream and cooler sea surface temperatures, possibly influenced by Pinatubo's aerosols, may have contributed to the storm's unusual development and strength.
The Perfect Storm originated from a cold front that exited the East coast of the United States. On October 28, the front spawned an extratropical low to the east of Nova Scotia. At the same time, a ridge extended from the Appalachian Mountains northeastward to Greenland, anchored by a strong high-pressure center over eastern Canada. The blocking ridge forced the developing extratropical low, which would normally have moved northeastward, to track southeastward and then westward in a rare retrograde motion, initiating a set of meteorological circumstances estimated to occur only once every 50 to 100 years (most nor'easters track northeastward, but this storm instead turned southwestward). On October 29, Hurricane Grace, a tropical system that had developed separately in the western Atlantic and that was moving northward, was swept into the warm conveyor belt of the deepening cyclone. By the next day, October 30, Grace was completely absorbed. The merger enhanced the intensity of the nor'easter, fueled by the sharp temperature contrast between cold air to the northwest and the warm, moist air from Grace's remnants.
At approximately 12:00 UTC on October 30, while situated about 390 miles (630 km) south of Halifax, Nova Scotia, the nor'easter reached peak intensity, with a central pressure of 972 mbar and winds of up to 70 mph (110 km/h). The strong pressure gradient between the storm and the blocking high to the north produced damaging winds and very large waves. Between the southern New England coast and the center of the storm, the pressure differential was 70 mbar (2.1 inHg). A buoy 264 miles (425 km) south of Halifax, Nova Scotia, recorded a wave height of 100.7 feet (30.7 m), the highest ever measured on the Scotian Shelf, the oceanic shelf off the coast of Nova Scotia. East of Cape Cod, at approximately 15:00 UTC on October 30, a NOAA buoy located at 41°06′N 66°36′W / 41.1°N 66.6°W recorded maximum sustained winds of 56 mph (90 km/h) with gusts to 75 mph (121 km/h), and a significant wave height (average height of the highest one-third of all waves) of 39 feet (12 m). Another buoy, located at 40°30′N 69°30′W / 40.5°N 69.5°W, recorded maximum sustained winds of 61 mph (98 km/h) with gusts to 72 mph (116 km/h) and a significant wave height of 31 feet (9.4 m) at approximately 00:00 UTC on October 31.
Upon peaking in intensity, the nor'easter turned southward and gradually weakened. By November 1, its pressure had risen to 998 millibars (29.5 inHg). The low moved over warm waters of the Gulf Stream, where bands of convection around the center began to organize. Around this time, the system attained subtropical characteristics. While the storm was moving in a counter-clockwise loop, a tropical cyclone had been identified at the center of the larger low (these conditions, although rare, had been observed: during 1980, Hurricane Karl formed within a larger non-tropical weather system). By approximately 14:00 UTC on November 1, an eye feature was forming, and the tropical cyclone reached its peak intensity with maximum sustained winds of 75 mph (121 km/h); these estimates, combined with reports from an Air Force Reserve Unit flight into the storm and confirmation that a warm-core center was present, indicated that the system had become a Category 1 hurricane on the Saffir–Simpson Hurricane Scale. The hurricane accelerated toward the northeast and quickly weakened back into a tropical storm. It made landfall near Halifax, Nova Scotia, at 14:00 UTC on November 2, with sustained winds of 45 mph (72 km/h). While the storm was approaching the coast, weather radars depicted curved rainbands on the western side of the system. After crossing over Prince Edward Island, the storm fully dissipated late on November 2.
For several days, weather models forecast the development of a significant storm off New England. However, the models were inadequate in forecasting coastal conditions, which in one instance failed to provide adequate warning. In addition, a post-storm assessment found an insufficient number of observation sites along the coast. On October 27, the Ocean Prediction Center noted that a "dangerous storm" would form within 36 hours, with its wording emphasizing the unusual nature of the storm. The National Weather Service likewise issued warnings for the potential storm, providing information to emergency service offices as well as the media. The public, however, was skeptical and did not recognize the threat. The timely warnings ultimately lowered the death toll; whereas the Perfect Storm caused 13 deaths, the blizzard of 1978 killed 99 people, and the 1938 New England hurricane killed 564 people.