Hurricane Octave (1989)
Encyclopedia
Hurricane Octave was a Category 4 hurricane which existed during the above-average 1989 Pacific hurricane season
. The remnants of Atlantic Tropical Depression Nine tracked westward across the Caribbean Sea
, entering the Pacific Ocean on September 3. It slowly developed, and organized into a tropical depression on September 8. It strengthened into a tropical storm on September 10, thus earning the name Octave . After strengthening into a hurricane the next day, Octave started to steadily intensify en route to a peak as a Category 4 hurricane of the Saffir–Simpson Hurricane Scale. After reaching peak winds of 135 mph (215 km/h) on September 13, Octave moved into a region of cooler waters. The hurricane weakened into a tropical storm on September 14 and a tropical depression the next day before dissipating on September 16. The remnants impacted California
and Arizona
. The remnants of the storm brought moderate rainfall to parts of California and Arizona as well as three F0
tornadoes.
that left west coast of Africa on August 21, 1989. Moving westward, the wave became better organized and developed into Atlantic
Tropical Depression Nine on August 27. However, strong wind shear
inhibited further development of the system, leading to it degenerating to a tropical wave. Upon weakening to wave, the system was situated roughly 400 miles (643.7 km) east of the Lesser Antilles
. Continuing westward, the system moved through the Caribbean Sea
without significant development before crossing Central America
and entering the Pacific Ocean on September 3. After remaining stationary for several days, the system was upgraded to a tropical depression on September 8 about 400 miles (643.7 km) south of the Mexican
coastline. Upon becoming a tropical cyclone
, the convection became well-organized. Octave took a general northwestward track as it intensified, becoming Tropical Storm Octave later that day.
Upon being named, Octave had developed a good outflow
and shear was decreasing, leading to forecasters at the National Hurricane Center
anticipating the storm to become a hurricane. The storm slowly strengthened over the following two days, becoming a strong tropical storm early on September 11. Octave later reached hurricane intensity late on September 11. as it developed an eye
. Meanwhile, Octave was being steered by an anticyclone over Mexico and a trough to the west allowed the hurricane to continue northwest. Continuing to intensify, it was soon upgraded to Category 2 status on the Saffir–Simpson Hurricane Scale. During the afternoon of September 13, Octave intensified into a major hurricane, a storm with sustained winds of at least 111 mph (178 km/h). Early the next day, the hurricane attained peak intensity as Category 4 hurricane, based on the Dvorak technique
, a tool used to estimate tropical cyclone intensity. At this time, maximum winds were estimated at 135 mph (215 km/h) along with a barometric pressure of 94.8 kPa (27.99 inHg).
Shortly after its peak, the storm moved over cooler waters, with sea surface temperature
s estimated to be as low as 26 °C (78.8 °F). By the end of the September 13, the eye
of Octave had become less defined as the hurricane weakened. Steady weakening took place as the storm continued a northwesterly track due to a trough. By September 14, Octave was downgraded into a tropical storm as winds dropped below 75 mph (120 km/h) It began to weaken rapidly as it turned west and was downgraded to a tropical depression late on September 15. After turning back towards the east, Octave rapidly dissipated on September 16 as steering current diminished. The remnant low dissipated on September 16 while located 150 mi (241.4 km) off the Baja California
coastline.
, the city of Redding
recorded 2.21 in (56.1 mm) of rain in a 12-hour span and 3.15 in (80 mm) in 24 hours. Sacramento
also recorded 1.56 in (39.6 mm) in 6 hours. Light rainfall was reported throughout southern California, with enough falling in Los Angeles
to make streets slippery. Moisture associated with Octave produced isolated showers in thunderstorms in parts of southern Arizona on September 16. The unusually heavy rainfall in California was the delayed results of a cloud-seeding operation in southern California and Arizona using the Cloudbuster Icarus. The operation was launched on September 1 but the effects took more than a week to show; the heavy rains were the most seen in California since 1987. In addition, a power outage in Lodi, California affected 7,000 costumers. Octave also produced minor damage to the grape
and raisin
crops.
1989 Pacific hurricane season
-Tropical Storm Adolph:The first storm of the season developed out of a weak area of low pressure situated about 570 mi south-southwest of Acapulco, Mexico. Tracking towards the west, the circluation briefly dissipated on May 30, before redeveloping the following day into Tropical...
. The remnants of Atlantic Tropical Depression Nine tracked westward across the Caribbean Sea
Caribbean Sea
The Caribbean Sea is a sea of the Atlantic Ocean located in the tropics of the Western hemisphere. It is bounded by Mexico and Central America to the west and southwest, to the north by the Greater Antilles, and to the east by the Lesser Antilles....
, entering the Pacific Ocean on September 3. It slowly developed, and organized into a tropical depression on September 8. It strengthened into a tropical storm on September 10, thus earning the name Octave . After strengthening into a hurricane the next day, Octave started to steadily intensify en route to a peak as a Category 4 hurricane of the Saffir–Simpson Hurricane Scale. After reaching peak winds of 135 mph (215 km/h) on September 13, Octave moved into a region of cooler waters. The hurricane weakened into a tropical storm on September 14 and a tropical depression the next day before dissipating on September 16. The remnants impacted California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
. The remnants of the storm brought moderate rainfall to parts of California and Arizona as well as three F0
Fujita scale
The Fujita scale , or Fujita-Pearson scale, is a scale for rating tornado intensity, based primarily on the damage tornadoes inflict on human-built structures and vegetation...
tornadoes.
Meteorological history
Hurricane Octave originated from a tropical waveTropical wave
Tropical waves, easterly waves, or tropical easterly waves, also known as African easterly waves in the Atlantic region, are a type of atmospheric trough, an elongated area of relatively low air pressure, oriented north to south, which move from east to west across the tropics causing areas of...
that left west coast of Africa on August 21, 1989. Moving westward, the wave became better organized and developed into Atlantic
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...
Tropical Depression Nine on August 27. However, strong 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...
inhibited further development of the system, leading to it degenerating to a tropical wave. Upon weakening to wave, the system was situated roughly 400 miles (643.7 km) east of the Lesser Antilles
Lesser Antilles
The Lesser Antilles are a long, partly volcanic island arc in the Western Hemisphere. Most of its islands form the eastern boundary of the Caribbean Sea with the Atlantic Ocean, with the remainder located in the southern Caribbean just north of South America...
. Continuing westward, the system moved through the Caribbean Sea
Caribbean Sea
The Caribbean Sea is a sea of the Atlantic Ocean located in the tropics of the Western hemisphere. It is bounded by Mexico and Central America to the west and southwest, to the north by the Greater Antilles, and to the east by the Lesser Antilles....
without significant development before crossing Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
and entering the Pacific Ocean on September 3. After remaining stationary for several days, the system was upgraded to a tropical depression on September 8 about 400 miles (643.7 km) south of the Mexican
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
coastline. Upon becoming a tropical cyclone
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...
, the convection became well-organized. Octave took a general northwestward track as it intensified, becoming Tropical Storm Octave later that day.
Upon being named, Octave had developed a good outflow
Outflow (meteorology)
Outflow, in meteorology, is air that flows outwards from a storm system. It is associated with ridging, or anticyclonic flow. In the low levels of the troposphere, outflow radiates from thunderstorms in the form of a wedge of rain-cooled air, which is visible as a thin rope-like cloud on weather...
and shear was decreasing, leading to forecasters at 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...
anticipating the storm to become a hurricane. The storm slowly strengthened over the following two days, becoming a strong tropical storm early on September 11. Octave later reached hurricane intensity late on September 11. as it developed an eye
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...
. Meanwhile, Octave was being steered by an anticyclone over Mexico and a trough to the west allowed the hurricane to continue northwest. Continuing to intensify, it was soon upgraded to Category 2 status on the Saffir–Simpson Hurricane Scale. During the afternoon of September 13, Octave intensified into a major hurricane, a storm with sustained winds of at least 111 mph (178 km/h). Early the next day, the hurricane attained peak intensity as Category 4 hurricane, based on the Dvorak technique
Dvorak technique
The Dvorak technique is a widely used system to subjectively estimate tropical cyclone intensity based solely on visible and infrared satellite images. Several agencies issue Dvorak intensity numbers for cyclones of sufficient intensity...
, a tool used to estimate tropical cyclone intensity. At this time, maximum winds were estimated at 135 mph (215 km/h) along with a barometric pressure of 94.8 kPa (27.99 inHg).
Shortly after its peak, the storm moved over cooler waters, with 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 estimated to be as low as 26 °C (78.8 °F). By the end of the September 13, the eye
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...
of Octave had become less defined as the hurricane weakened. Steady weakening took place as the storm continued a northwesterly track due to a trough. By September 14, Octave was downgraded into a tropical storm as winds dropped below 75 mph (120 km/h) It began to weaken rapidly as it turned west and was downgraded to a tropical depression late on September 15. After turning back towards the east, Octave rapidly dissipated on September 16 as steering current diminished. The remnant low dissipated on September 16 while located 150 mi (241.4 km) off the Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
coastline.
Preparations and impact
Prior to the arrival of Octave, the NHC issued public advisories. The advisories noted that 1 to 2 in (25.4 to 50.8 mm) was possible in the higher elevations. The possibility of a dissipating prior to landfall was also noted. Octave came within 200 mi (321.9 km) of Socorro Island. As a result, the weather station there reported winds of 35 mph (56.3 km/h) and a pressure of 100.36 kPa (29.6 inHg). In addition, its remnants did move into California. In the Sacramento ValleySacramento Valley
The Sacramento Valley is the portion of the California Central Valley that lies to the north of the San Joaquin-Sacramento Delta in the U.S. state of California. It encompasses all or parts of ten counties.-Geography:...
, the city of Redding
Redding, California
Redding is a city in far-Northern California. It is the county seat of Shasta County, California, USA. With a population of 89,861, according to the 2010 Census...
recorded 2.21 in (56.1 mm) of rain in a 12-hour span and 3.15 in (80 mm) in 24 hours. Sacramento
Sacramento, California
Sacramento is the capital city of the U.S. state of California and the county seat of Sacramento County. It is located at the confluence of the Sacramento River and the American River in the northern portion of California's expansive Central Valley. With a population of 466,488 at the 2010 census,...
also recorded 1.56 in (39.6 mm) in 6 hours. Light rainfall was reported throughout southern California, with enough falling in Los Angeles
Los Angeles, California
Los Angeles , with a population at the 2010 United States Census of 3,792,621, is the most populous city in California, USA and the second most populous in the United States, after New York City. It has an area of , and is located in Southern California...
to make streets slippery. Moisture associated with Octave produced isolated showers in thunderstorms in parts of southern Arizona on September 16. The unusually heavy rainfall in California was the delayed results of a cloud-seeding operation in southern California and Arizona using the Cloudbuster Icarus. The operation was launched on September 1 but the effects took more than a week to show; the heavy rains were the most seen in California since 1987. In addition, a power outage in Lodi, California affected 7,000 costumers. Octave also produced minor damage to the grape
Grape
A grape is a non-climacteric fruit, specifically a berry, that grows on the perennial and deciduous woody vines of the genus Vitis. Grapes can be eaten raw or they can be used for making jam, juice, jelly, vinegar, wine, grape seed extracts, raisins, molasses and grape seed oil. Grapes are also...
and raisin
Raisin
Raisins are dried grapes. They are produced in many regions of the world. Raisins may be eaten raw or used in cooking, baking and brewing...
crops.
See also
- List of California hurricanes
- List of Pacific hurricanes
- 1989 Pacific hurricane season1989 Pacific hurricane season-Tropical Storm Adolph:The first storm of the season developed out of a weak area of low pressure situated about 570 mi south-southwest of Acapulco, Mexico. Tracking towards the west, the circluation briefly dissipated on May 30, before redeveloping the following day into Tropical...