Hurricane Julia (2010)
Encyclopedia
Hurricane Julia was the easternmost Category 4 hurricane recorded in the Atlantic basin
since reliable satellite observations became available. The twelfth tropical cyclone, fifth hurricane and fourth major hurricane of the 2010 Atlantic hurricane season, Julia rapidly developed on September 12 from a tropical wave
near Cape Verde
. Passing near the islands, the system quickly organized into Tropical Storm Julia the next day. On September 14, Julia attained hurricane status and subsequently entered a trend of rapid intensification
; the storm strengthened from a minimal hurricane to a low-end Category 4 in only 24 hours. After peaking in intensity, further development was impeded as interaction with nearby Hurricane Igor
began to occur; the storm was downgraded to a tropical storm by September 18. It subsequently moved into a region of unfavorable conditions, heading toward lower sea surface temperature
s. Correspondingly, Julia entered an extratropical transition on September 20, and advisories on the storm were discontinued by that time.
As Julia never posed any significant threat to land, damage related to the storm was minimal. Trace amounts of rain reportedly fell across the Cape Verde islands, causing locally light flooding and minor inconveniences. Gusts battering the territory peaked at 30 mph (48 km/h), resulting in some wind damage to crops. In addition, these winds produced rough sea conditions, and high waves posed few threats along coastlines.
, or an equator
ward low-pressure area, which emerged into the Atlantic along the western coast of Africa
on September 11. At the time, the system maintained deep convection
and strong easterly winds, prompting the National Hurricane Center
(NHC) to commence tracking the system as an area of interest. As the wave moved generally westward at 10 to 15 mph (16 to 24 km/h), a quick increase in organization as well as a significant drop in surface pressure
became notable. The system continued to organize, and several hours later, the NHC noted only a slight increase would suffice for the development of a tropical cyclone. By September 12, a tropical depression developed
, and the NHC initiated advisories at 1500 UTC
that day. At the time, the cyclone was situated 250 mi (400 km) southeast of the southernmost islands of Cape Verde
.
For several hours, steady strengthening continued as the depression maintained a westward track. Operationally, it was upgraded to Tropical Storm Julia early on September 13, though post-analysis confirmed the storm had reached winds of 40 mph (65 km/h) twelve hours after formation. For several hours, no significant change occurred in its intensity or organization as Julia passed near Cape Verde, though the storm gradually retraced to the west-northwest along the southern periphery of a deep-layer ridge
. Slow intensification resumed as the storm bypassed the Cape Verde islands; by early September 14, it displayed a ragged, banded eye-like feature
in satellite imagery
. Due to locally high sea surface temperature
s of about 28° C (82º F), a period of rapid intensification subsequently commenced; within hours, Julia attained Category 1 hurricane status. Though located over an area with relatively low oceanic heat content, Julia continued to intensify rapidly under low vertical wind shear
and over favorable sea surface temperatures; as such, the hurricane was upgraded to Category 2 status on September 15. In less than two hours, the hurricane deepened to reach Category 3 intensity, becoming the fourth major hurricane of the season. The rapid intensification trend continued, and Julia eventually strengthened into a Category 4 hurricane six hours later. Based on satellite estimates, its winds peaked at 140 mph (220 km/h) and a minimum barometric pressure of 948 mbar
(hPa
; 27.99 inHg), though operationally estimated at 135 mph (215 km/h) and 950 mbar (hPa; 28.05 inHg), respectively.
Upon peaking in intensity, Julia accelerated slightly as it re-curved toward the northwest along a mid to upper-level low
to its southwest. In addition, this system generated unfavorable southerly flow aloft, inducing a slight weakening of the storm. By early September 16, Julia's eye became indistinguishable on satellite images, and the storm further dropped to below major hurricane status. Upon doing so, Julia became embedded within a south-southeasterly steering current along deep-layer ridging in its vicinity, resulting in a more westward track. Though still a hurricane, the relatively small tropical system moved to the east of the much larger Hurricane Igor. Concurrently, Igor's outflow began impinging on Julia's circulation, and due to colder sea surface temperatures, the storm weakened below hurricane intensity late on September 17. Henceforth, Julia re-accelerated as it further curved northward around the contiguous ridge, nearly merging with Igor as a result. Progressively tracking to the north over the next hours, Julia subsequently executed a turn to the northeast, then to the east. Proceeding eastward, the low-level center of the storm became partially exposed on September 18; however, for several hours thereafter, convection gradually redeveloped over its center. Despite the deep convection, vertical wind shear again increased over the system, causing the storm to enter an extratropical transition
. It is estimated Julia degenerated into a post-tropical low by 1800 UTC on September 20, while located about 1095 mi (1750 km) west of the Azores
. The resultant storm meandered around over the Atlantic for several days, continuing generally eastward before executing an elongated loop to the south. Following this erratic track, the remnants of Hurricane Julia proceeded northwestward and came within 350 mi (563 km) of Bermuda
, where they were once again briefly monitored by the NHC. However, chance of redevelopment dwindled, as conditions were not conducive for tropical formation; convection nearly diminished entirely, and the NHC discontinued monitoring the system on September 28.
. At the time, at least 3 to 5 in (76 to 127 mm) of precipitation was expected, with locally accumulations of up to 8 in (203 mm). In response, the Government of Cape Verde issued a tropical storm warning for the southern portion of the archipelago, which included Maio
, Sao Tiago
, Fogo
, and Brava
. The tropical storm warning remained in effect after Julia intensified into a tropical storm; it was finally discontinued early on September 14.
Since Julia stayed at sea and never directly struck land as a significant cyclone, there were no reports of major damage or casualties. Across southern Cape Verde, intermittent rains and some gusty winds were reported when the storm neared the islands. Winds reached between 24 and 30 mph (38 and 48 km/h); the only known report of rainfall accumulations was in Sal
, where no more than 0.39 in (9.9 mm) of precipitation was recorded. During the passage of the storm, authorities canceled several local and international flights across Cape Verde. In Sao Tiago, floods triggered several landslides, resulting in the isolation of the community of Covão Grande from roadways. Several communities also reported wind damage to maiz crops. In addition, rough seas with waves of 9.8 to 14.8 ft (3 to 4.5 m) resulted in minor disruptions along coastlines.
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
since reliable satellite observations became available. The twelfth tropical cyclone, fifth hurricane and fourth major hurricane of the 2010 Atlantic hurricane season, Julia rapidly developed on September 12 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...
near Cape Verde
Cape Verde
The Republic of Cape Verde is an island country, spanning an archipelago of 10 islands located in the central Atlantic Ocean, 570 kilometres off the coast of Western Africa...
. Passing near the islands, the system quickly organized into Tropical Storm Julia the next day. On September 14, Julia attained hurricane status and subsequently entered a trend of rapid intensification
Rapid deepening
Rapid deepening, also known as rapid intensification, is a meteorological condition that occurs when the minimum sea-level atmospheric pressure of a tropical cyclone decreases drastically in a short period of time. The National Weather Service describes rapid deepening as a decrease of...
; the storm strengthened from a minimal hurricane to a low-end Category 4 in only 24 hours. After peaking in intensity, further development was impeded as interaction with nearby Hurricane Igor
Hurricane Igor (2010)
Hurricane Igor was the most destructive tropical cyclone to strike the Canadian island of Newfoundland on record. The origins of Igor were within a broad area of low pressure that moved off the west coast of Africa on September 6, 2010. Tracking slowly westward, it developed into a tropical...
began to occur; the storm was downgraded to a tropical storm by September 18. It subsequently moved into a region of unfavorable conditions, heading toward lower sea surface temperature
Sea surface temperature
Sea surface temperature is the water temperature close to the oceans surface. The exact meaning of surface varies according to the measurement method used, but it is between and below the sea surface. Air masses in the Earth's atmosphere are highly modified by sea surface temperatures within a...
s. Correspondingly, Julia entered an extratropical transition on September 20, and advisories on the storm were discontinued by that time.
As Julia never posed any significant threat to land, damage related to the storm was minimal. Trace amounts of rain reportedly fell across the Cape Verde islands, causing locally light flooding and minor inconveniences. Gusts battering the territory peaked at 30 mph (48 km/h), resulting in some wind damage to crops. In addition, these winds produced rough sea conditions, and high waves posed few threats along coastlines.
Meteorological history
The origins of Julia trace back to a vigorous 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...
, or an equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
ward low-pressure area, which emerged into the Atlantic along the western coast of Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
on September 11. At the time, the system maintained deep convection
Atmospheric convection
Atmospheric convection is the result of a parcel-environment instability, or temperature difference, layer in the atmosphere. Different lapse rates within dry and moist air lead to instability. Mixing of air during the day which expands the height of the planetary boundary layer leads to...
and strong easterly winds, prompting 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) to commence tracking the system as an area of interest. As the wave moved generally westward at 10 to 15 mph (16 to 24 km/h), a quick increase in organization as well as a significant drop in surface pressure
Surface pressure
Surface pressure is the atmospheric pressure at a location on Earth's surface. It is directly proportional to the mass of air over that location....
became notable. The system continued to organize, and several hours later, the NHC noted only a slight increase would suffice for the development of a tropical cyclone. By September 12, a tropical depression developed
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...
, and the NHC initiated advisories at 1500 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...
that day. At the time, the cyclone was situated 250 mi (400 km) southeast of the southernmost islands of Cape Verde
Cape Verde
The Republic of Cape Verde is an island country, spanning an archipelago of 10 islands located in the central Atlantic Ocean, 570 kilometres off the coast of Western Africa...
.
For several hours, steady strengthening continued as the depression maintained a westward track. Operationally, it was upgraded to Tropical Storm Julia early on September 13, though post-analysis confirmed the storm had reached winds of 40 mph (65 km/h) twelve hours after formation. For several hours, no significant change occurred in its intensity or organization as Julia passed near Cape Verde, though the storm gradually retraced to the west-northwest along the southern periphery of a deep-layer ridge
Ridge (meteorology)
A ridge is an elongated region of relatively high atmospheric pressure, the opposite of a trough....
. Slow intensification resumed as the storm bypassed the Cape Verde islands; by early September 14, it displayed a ragged, banded eye-like 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...
in satellite imagery
Weather satellite
The weather satellite is a type of satellite that is primarily used to monitor the weather and climate of the Earth. Satellites can be either polar orbiting, seeing the same swath of the Earth every 12 hours, or geostationary, hovering over the same spot on Earth by orbiting over the equator while...
. Due to locally high sea surface temperature
Sea surface temperature
Sea surface temperature is the water temperature close to the oceans surface. The exact meaning of surface varies according to the measurement method used, but it is between and below the sea surface. Air masses in the Earth's atmosphere are highly modified by sea surface temperatures within a...
s of about 28° C (82º F), a period of rapid intensification subsequently commenced; within hours, Julia attained Category 1 hurricane status. Though located over an area with relatively low oceanic heat content, Julia continued to intensify rapidly under low vertical wind shear
Wind shear
Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...
and over favorable sea surface temperatures; as such, the hurricane was upgraded to Category 2 status on September 15. In less than two hours, the hurricane deepened to reach Category 3 intensity, becoming the fourth major hurricane of the season. The rapid intensification trend continued, and Julia eventually strengthened into a Category 4 hurricane six hours later. Based on satellite estimates, its winds peaked at 140 mph (220 km/h) and a minimum barometric pressure of 948 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...
(hPa
Pascal (unit)
The pascal is the SI derived unit of pressure, internal pressure, stress, Young's modulus and tensile strength, named after the French mathematician, physicist, inventor, writer, and philosopher Blaise Pascal. It is a measure of force per unit area, defined as one newton per square metre...
; 27.99 inHg), though operationally estimated at 135 mph (215 km/h) and 950 mbar (hPa; 28.05 inHg), respectively.
Upon peaking in intensity, Julia accelerated slightly as it re-curved toward the northwest along a mid to upper-level low
Cold-core low
A cold-core low, also known as a cold low or cold-core cyclone, is a cyclone aloft which has an associated cold pool of air residing at high altitude within the Earth's troposphere. It is a low pressure system which strengthens with height in accordance with the thermal wind relationship. These...
to its southwest. In addition, this system generated unfavorable southerly flow aloft, inducing a slight weakening of the storm. By early September 16, Julia's eye became indistinguishable on satellite images, and the storm further dropped to below major hurricane status. Upon doing so, Julia became embedded within a south-southeasterly steering current along deep-layer ridging in its vicinity, resulting in a more westward track. Though still a hurricane, the relatively small tropical system moved to the east of the much larger Hurricane Igor. Concurrently, Igor's outflow began impinging on Julia's circulation, and due to colder sea surface temperatures, the storm weakened below hurricane intensity late on September 17. Henceforth, Julia re-accelerated as it further curved northward around the contiguous ridge, nearly merging with Igor as a result. Progressively tracking to the north over the next hours, Julia subsequently executed a turn to the northeast, then to the east. Proceeding eastward, the low-level center of the storm became partially exposed on September 18; however, for several hours thereafter, convection gradually redeveloped over its center. Despite the deep convection, vertical wind shear again increased over the system, causing the storm to enter an extratropical transition
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...
. It is estimated Julia degenerated into a post-tropical low by 1800 UTC on September 20, while located about 1095 mi (1750 km) west 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...
. The resultant storm meandered around over the Atlantic for several days, continuing generally eastward before executing an elongated loop to the south. Following this erratic track, the remnants of Hurricane Julia proceeded northwestward and came within 350 mi (563 km) of Bermuda
Bermuda
Bermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, its nearest landmass is Cape Hatteras, North Carolina, about to the west-northwest. It is about south of Halifax, Nova Scotia, Canada, and northeast of Miami, Florida...
, where they were once again briefly monitored by the NHC. However, chance of redevelopment dwindled, as conditions were not conducive for tropical formation; convection nearly diminished entirely, and the NHC discontinued monitoring the system on September 28.
Preparations and impact
Immediately upon developing into a tropical depression, Julia posed a threat to Cape VerdeCape Verde
The Republic of Cape Verde is an island country, spanning an archipelago of 10 islands located in the central Atlantic Ocean, 570 kilometres off the coast of Western Africa...
. At the time, at least 3 to 5 in (76 to 127 mm) of precipitation was expected, with locally accumulations of up to 8 in (203 mm). In response, the Government of Cape Verde issued a tropical storm warning for the southern portion of the archipelago, which included Maio
Maio, Cape Verde
Maio is the easternmost of the Sotavento islands of Cape Verde. Maio is located south of the islands of Boa Vista and east of Santiago. The island is also known for its large forest, which is unusual for Cape Verde.-Geography:The island covers an area of 269 km²...
, Sao Tiago
Santiago, Cape Verde
Santiago , or Santiagu in Cape Verdean Creole, is the largest island of Cape Verde, its most important agricultural centre and home to half the nation’s population. At the time of Darwin's voyage it was called St. Jago....
, Fogo
Fogo, Cape Verde
Fogo is an island in the Sotavento group of Cape Verde. It is the most prominent of the group, rising to nearly 3,000 m above sea level at Pico do Fogo.-Geography:...
, and Brava
Brava, Cape Verde
Brava is an island in Cape Verde. It is the smallest inhabited island, but at the same time the greenest, of Cape Verde, in the Sotavento group. First settled in the 1540s, its population grew after Mount Fogo on neighbouring Fogo erupted in 1675...
. The tropical storm warning remained in effect after Julia intensified into a tropical storm; it was finally discontinued early on September 14.
Since Julia stayed at sea and never directly struck land as a significant cyclone, there were no reports of major damage or casualties. Across southern Cape Verde, intermittent rains and some gusty winds were reported when the storm neared the islands. Winds reached between 24 and 30 mph (38 and 48 km/h); the only known report of rainfall accumulations was in Sal
Sal, Cape Verde
Sal is an island in Cape Verde. It belongs to the northern group of islands, called Barlavento. The island is composed by a single administrative division, the Sal municipality. The island is home to Amílcar Cabral International Airport, the main airport of Cape Verde.- Geography :The island is...
, where no more than 0.39 in (9.9 mm) of precipitation was recorded. During the passage of the storm, authorities canceled several local and international flights across Cape Verde. In Sao Tiago, floods triggered several landslides, resulting in the isolation of the community of Covão Grande from roadways. Several communities also reported wind damage to maiz crops. In addition, rough seas with waves of 9.8 to 14.8 ft (3 to 4.5 m) resulted in minor disruptions along coastlines.