Hurricane Karl (1980)
Encyclopedia
Hurricane Karl was a late-season and unusual tropical cyclone
that formed during the 1980 Atlantic hurricane season
. A minimal Category 1 hurricane on the Saffir–Simpson Hurricane Scale, Karl developed at the center of another, larger extratropical cyclone
over the North Atlantic. After being classified a subtropical cyclone
on November 25, it became more independent of its parent storm and grew into a full-fledged hurricane. It peaked in intensity on November 26, and ultimately dissipated as it merged with another system.
Karl holds the record for the northernmost formation of a November tropical or subtropical cyclone in the Atlantic Ocean. It also attained hurricane strength at an unusual latitude, and contributed to one of the most active Novembers on record in terms of tropical cyclones. However, it stayed over open waters and did not have any effects on land. It was the 11th named storm of the season, and due to the lack of damage, its name was not retired.
that formed along a frontal boundary
near the southeastern United States. It approached the Canadian Maritimes the next day and strengthened to below 1000 millibars. On November 24, the broad cyclone was located south of Newfoundland, and early the next day a mass of convection developed near the core. It evolved into a separate vortex, and due to the lack of inhibiting wind shear
, a small cyclone developed. It became a subtropical storm at 0000 UTC before executing a tight counterclockwise loop as it rotated within the larger cyclone. About 18 hours later, the storm strengthened and gained enough tropical characteristics to be designated a hurricane, accompanied by the formation of a pronounced eye feature
. At the time, it was situated around 610 miles (1,110 km) west-southwest of the Azores
. Although the development of a tropical cyclone within a non-tropical storm is rare, it is not unprecedented. An unnamed hurricane in November 1991 also formed in this manner.
After being classified as a hurricane, Karl gradually strengthened, and its circulation became more distinguished from the surrounding cloudiness. A trough
that emerged from North America steered the hurricane eastward, and on November 26, it reached its peak intensity with maximum sustained winds of 85 mph (140 km/h) and a central barometric pressure reading of 985 mbar (hPa; 29.09 inHg). Karl maintained this strength for approximately 18 hours until beginning to weaken slightly as it accelerated towards the northeast. On November 27, the storm's eye became more ragged as the cyclone passed within 230 miles (370 km) of the Azores and started to showed signs of deterioration. The trough over the North Atlantic developed into the dominant low pressure area, and Karl turned northward around its periphery. It merged with another approaching system and was declared dissipated by November 28.
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Hurricane Karl was unusual in several aspects. It developed late in the hurricane season, which runs from June 1 through November 30, over waters colder than the standard limit for tropical cyclone formation. It marked the farthest-north development of a November tropical or subtropical cyclone on record. While the 1991 unnamed hurricane was farther north, it became a subtropical storm late on October 31, and had moved south by November 1. Karl attained Category 1 hurricane status farther north than any other storm (in any month) until the 1991 unnamed hurricane became a hurricane at a higher latitude. The storm's record was also surpassed by Hurricane Noel
in 2001. Karl was reported at the time to be the farthest-east hurricane during the last 10 days of the month of November. Additionally, it maintained hurricane intensity until reaching 45.0°N, at which point it became extratropical; only Hurricane Lois in 1966 lasted as a hurricane farther north in the month of November.
When Karl became a hurricane on November 25, the 1980 season became notable for having two November hurricanes; the other was Jeanne
. This tied 1932
and 1969
for the record of the most November hurricanes, which was later accomplished during the 1994 season
. Later, 2001
broke this record with three hurricanes. The cyclone never affected land, and as a result, no deaths or damages occurred. One ship to the northwest of Karl's center recorded 35 mph (55 km/h) winds and an air pressure of 993 mbar.
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...
that formed during the 1980 Atlantic hurricane season
1980 Atlantic hurricane season
The 1980 Atlantic hurricane season officially began on June 1, 1980, and lasted until November 30, 1980. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. The season was fairly active, with eleven storms forming, of which nine reached...
. A minimal Category 1 hurricane on the Saffir–Simpson Hurricane Scale, Karl developed at the center of another, larger 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...
over the North Atlantic. After being classified 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...
on November 25, it became more independent of its parent storm and grew into a full-fledged hurricane. It peaked in intensity on November 26, and ultimately dissipated as it merged with another system.
Karl holds the record for the northernmost formation of a November tropical or subtropical cyclone in the Atlantic Ocean. It also attained hurricane strength at an unusual latitude, and contributed to one of the most active Novembers on record in terms of tropical cyclones. However, it stayed over open waters and did not have any effects on land. It was the 11th named storm of the season, and due to the lack of damage, its name was not retired.
Meteorological history
Hurricane Karl originated in a low pressure areaLow 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...
that formed along a frontal boundary
Weather front
A weather front is a boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena. In surface weather analyses, fronts are depicted using various colored lines and symbols, depending on the type of front...
near the southeastern United States. It approached the Canadian Maritimes the next day and strengthened to below 1000 millibars. On November 24, the broad cyclone was located south of Newfoundland, and early the next day a mass of convection developed near the core. It evolved into a separate vortex, and due to the lack of inhibiting 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...
, a small cyclone developed. It became a subtropical storm at 0000 UTC before executing a tight counterclockwise loop as it rotated within the larger cyclone. About 18 hours later, the storm strengthened and gained enough tropical characteristics to be designated a hurricane, accompanied by the formation of a pronounced eye feature
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...
. At the time, it was situated around 610 miles (1,110 km) west-southwest of the Azores
Azores
The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...
. Although the development of a tropical cyclone within a non-tropical storm is rare, it is not unprecedented. An unnamed hurricane in November 1991 also formed in this manner.
After being classified as a hurricane, Karl gradually strengthened, and its circulation became more distinguished from the surrounding cloudiness. A 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...
that emerged from North America steered the hurricane eastward, and on November 26, it reached its peak intensity with maximum sustained winds of 85 mph (140 km/h) and a central barometric pressure reading of 985 mbar (hPa; 29.09 inHg). Karl maintained this strength for approximately 18 hours until beginning to weaken slightly as it accelerated towards the northeast. On November 27, the storm's eye became more ragged as the cyclone passed within 230 miles (370 km) of the Azores and started to showed signs of deterioration. The trough over the North Atlantic developed into the dominant low pressure area, and Karl turned northward around its periphery. It merged with another approaching system and was declared dissipated by November 28.
Records and impact
Hurricane Noel (2001)
The November 2001 Atlantic Canada storm complex was a powerful coastal storm that included the remnants of Atlantic hurricanes Michelle and Noel. The low intensified as it moved westward into Atlantic Canada on November 6, reaching pressures as low as 946 mbar. The storm turned to the...
in 2001. Karl was reported at the time to be the farthest-east hurricane during the last 10 days of the month of November. Additionally, it maintained hurricane intensity until reaching 45.0°N, at which point it became extratropical; only Hurricane Lois in 1966 lasted as a hurricane farther north in the month of November.
When Karl became a hurricane on November 25, the 1980 season became notable for having two November hurricanes; the other was Jeanne
Hurricane Jeanne (1980)
Hurricane Jeanne was a moderate hurricane that formed and dissipated in the Gulf of Mexico without making landfall. The tenth tropical cyclone and eighth hurricane of the 1980 Atlantic hurricane season, Jeanne developed over the southern Caribbean on November 7. It moved swiftly northward, and it...
. This tied 1932
1932 Atlantic hurricane season
The 1932 Atlantic hurricane season ran through the summer and the first half of fall in 1932. The 1932 season was an active one. An early tropical storm formed in May and hit Hispaniola, causing minimal damage. A Category 4 struck Galveston, Texas and the Galveston Seawall proved its worth. A...
and 1969
1969 Atlantic hurricane season
The 1969 Atlantic hurricane season officially began on June 1, 1969, and lasted until November 30, 1969. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. The season was among the most active on record, with 18 tropical cyclones, 12...
for the record of the most November hurricanes, which was later accomplished during the 1994 season
1994 Atlantic hurricane season
The 1994 Atlantic hurricane seasonofficially began June 1, 1994, and officially ended November 30, 1994. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin....
. Later, 2001
2001 Atlantic hurricane season
The 2001 Atlantic hurricane season was a fairly active Atlantic hurricane season that produced 17 tropical cyclones, 15 named storms, nine hurricanes, and four major hurricanes. The season officially lasted from June 1, 2001, to November 30, 2001, dates which by convention limit the period of each...
broke this record with three hurricanes. The cyclone never affected land, and as a result, no deaths or damages occurred. One ship to the northwest of Karl's center recorded 35 mph (55 km/h) winds and an air pressure of 993 mbar.
See also
- 1980 Atlantic hurricane season1980 Atlantic hurricane seasonThe 1980 Atlantic hurricane season officially began on June 1, 1980, and lasted until November 30, 1980. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. The season was fairly active, with eleven storms forming, of which nine reached...
- Other tropical cyclones named Karl
