|Tropical storm (SSHWS/NWS)|
|Formed||June 14, 2018|
|Dissipated||June 19, 2018|
|Highest winds|| 1-minute sustained:65 mph (100 km/h)|
|Lowest pressure||997 mbar (hPa); 29.44 inHg|
|Areas affected||Central and Southern Mexico|
|Part of the 2018 Pacific hurricane season|
Tropical Storm Carlotta was a tropical cyclone that caused flooding within several states in southwestern and central Mexico. Carlotta formed as the result of a breakdown in the Intertropical Convergence Zone to the south of Mexico. On June 12, a broad area of low pressure formed several hundred miles south of the aforementioned country and strengthened into a tropical storm by June 15. On the next day, the storm unexpectedly stalled within a favorable environment, which led to more intensification than originally anticipated. Early on June 17, Carlotta reached peak intensity with maximum sustained winds of 65 mph (100 km/h) and a minimum central pressure of 997 mbar (29.44 inHg) while located only 30 mi (50 km) south-southeast of Acapulco. Soon after, Carlotta began to interact with land and experience wind shear, which resulted in the system weakening to tropical depression status later in the day. The storm weakened to a remnant low early on June 19 and dissipated several hours later.
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain. Depending on its location and strength, a tropical cyclone is referred to by different names, including hurricane, typhoon, tropical storm, cyclonic storm, tropical depression, and simply cyclone. A hurricane is a tropical cyclone that occurs in the Atlantic Ocean and northeastern Pacific Ocean, and a typhoon occurs in the northwestern Pacific Ocean; in the south Pacific or Indian Ocean, comparable storms are referred to simply as "tropical cyclones" or "severe cyclonic storms".
Mexico, officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Covering almost 2,000,000 square kilometres (770,000 sq mi), the nation is the fifth largest country in the Americas by total area and the 13th largest independent state in the world. With an estimated population of over 120 million people, the country is the tenth most populous state and the most populous Spanish-speaking state in the world, while being the second most populous nation in Latin America after Brazil. Mexico is a federation comprising 31 states and Mexico City, a special federal entity that is also the capital city and its most populous city. Other metropolises in the state include Guadalajara, Monterrey, Puebla, Toluca, Tijuana and León.
The Intertropical Convergence Zone (ITCZ), known by sailors as the doldrums or the calms because of its monotonous, windless weather, is the area where the northeast and southeast trade winds converge. It encircles Earth near the thermal equator, though its specific position varies seasonally. When it lies near the geographic Equator, it is called the near-equatorial trough. Where the ITCZ is drawn into and merges with a monsoonal circulation, it is sometimes referred to as a monsoon trough, a usage more common in Australia and parts of Asia.
Carlotta prompted the issuance of multiple watches and warnings for the southern coast of Mexico. The storm caused a total of three deaths; two in Aguascalientes and one in Oaxaca. Additionally, the storm caused flooding and landslides throughout the states of Aguascalientes, Guerrero, Michoacán, Oaxaca, and Puebla, as well as the Yucatán Peninsula. Damage from the system was reported to be minor.
Aguascalientes, officially the Free and Sovereign State of Aguascalientes, is one of the 31 states which, with Mexico City, comprise the 32 Federal Entities of Mexico. It is divided into 11 municipalities and its capital city is Aguascalientes.
Oaxaca, officially the Free and Sovereign State of Oaxaca, is one of the 31 states which, along with Mexico City, make up the 32 federative entities of Mexico. It is divided into 570 municipalities, of which 418 are governed by the system of usos y costumbres with recognized local forms of self-governance. Its capital city is Oaxaca de Juárez.
Guerrero, officially the Free and Sovereign State of Guerrero, is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 81 municipalities and its capital city is Chilpancingo and its largest city is Acapulco.
Tropical Storm Carlotta formed as the result of a breakdown in the Intertropical Convergence Zone to the south of Mexico. However, a tropical wave that crossed over Central America around June 11 may have contributed to Carlotta's formation as well. 86 °F (30 °C), the depression experienced minimal change in intensity over the next 18 hours. After the system's center reformed farther north, the NHC reduced its intensity forecast as the storm would have less time over water. However, Carlotta never made landfall during its existence as a tropical cyclone. Around 18:00 UTC on June 15, the system strengthened into a tropical storm, after which it was assigned the name Carlotta. The system's intensity then leveled off for about twelve hours.On June 12, the National Hurricane Center (NHC) reported that a broad area of low pressure had formed several hundred miles south of southeastern Mexico. The NHC continued to monitor the disturbance over the next couple days as it drifted northward. Initially, strong upper-level winds prevented development, but the system unexpectedly organized on June 14. Following structural improvements, the NHC upgraded the system into a tropical depression at 18:00 UTC while about 140 mi (220 km) south of Acapulco. Around that time, the NHC forecast that a mid-level ridge over Mexico would weaken on the next day, leaving the depression in an area of light steering currents. Despite being located in an environment with low to moderate wind shear and sea surface temperatures exceeding
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 moves from east to west across the tropics, causing areas of cloudiness and thunderstorms. West-moving waves can also form from the tail end of frontal zones in the subtropics and tropics, and may be referred to as easterly waves, but these waves are not properly called tropical waves; they are a form of inverted trough sharing many characteristics with fully tropical waves. All tropical waves form in the easterly flow along the equatorward side of the subtropical ridge or belt of high pressure which lies north and south of the Intertropical Convergence Zone (ITCZ). Tropical waves are generally carried westward by the prevailing easterly winds along the tropics and subtropics near the equator. They can lead to the formation of tropical cyclones in the north Atlantic and northeastern Pacific basins. A tropical wave study is aided by Hovmöller diagrams, a graph of meteorological data.
Central America is located on the southern tip of North America, or is sometimes defined as a subcontinent of the Americas, bordered by Mexico to the north, Colombia to the southeast, the Caribbean Sea to the east, and the Pacific Ocean to the west and south. Central America consists of seven countries: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama. The combined population of Central America has been estimated to be 41,739,000 and 42,688,190.
The National Hurricane Center (NHC) is the division of the United States' National Weather Service responsible for tracking and predicting tropical weather systems between the Prime Meridian and the 140th meridian west poleward to the 30th parallel north in the northeast Pacific Ocean and the 31st parallel north in the northern Atlantic Ocean. The agency, which is co-located with the Miami branch of the National Weather Service, is situated on the campus of Florida International University in University Park, Florida.
Early on June 16, Carlotta's forward motion began to fluctuate, changing from northeast to southeast in six hours.Carlotta began to intensify again around 06:00 UTC as it stalled off the coast of Mexico. Soon after, the cyclone began moving in a northerly direction. Over the next twelve hours, Carlotta experienced little change in organization before peaking at 00:00 UTC on June 17 with maximum sustained winds of 65 mph (100 km/h) and a minimum central pressure of 997 mbar (29.44 inHg) while located only 30 mi (50 km) south-southeast of Acapulco. Around that time, the NHC noted that the system's structure had improved significantly, with a contracting eye and more symmetric eyewall. Soon after, Carlotta began to weaken due to increasing interactions with land and northerly wind shear. Meanwhile, the system had begun tracking towards the northwest. Around 18:00 UTC on the same day, Carlotta weakened into a tropical depression after lacking organized deep convection for several hours. Over the next day, Carlotta continued to weaken before degenerating into a remnant low on June 19 at 00:00 UTC. Soon after, Carotta's upper-level circulation decoupled entirely and drifted towards the southwest, while the low- and mid-level remnants remained. Carlotta's remnants dissipated around 06:00 UTC while located offshore of the coast between Manzanillo and Zihuatanejo, Mexico.
The maximum sustained wind associated with a tropical cyclone is a common indicator of the intensity of the storm. Within a mature tropical cyclone, it is found within the eyewall at a distance defined as the radius of maximum wind, or RMW. Unlike gusts, the value of these winds are determined via their sampling and averaging the sampled results over a period of time. Wind measuring has been standardized globally to reflect the winds at 10 metres (33 ft) above the Earth's surface, and the maximum sustained wind represents the highest average wind over either a one-minute (US) or ten-minute time span, anywhere within the tropical cyclone. Surface winds are highly variable due to friction between the atmosphere and the Earth's surface, as well as near hills and mountains over land.
Atmospheric pressure, sometimes also called barometric pressure, is the pressure within the atmosphere of Earth. The standard atmosphere is a unit of pressure defined as 1013.25 mbar (101325 Pa), equivalent to 760 mm Hg (torr), 29.9212 inches Hg, or 14.696 psi. The atm unit is roughly equivalent to the mean sea-level atmospheric pressure on Earth, that is, the Earth's atmospheric pressure at sea level is approximately 1 atm.
The eye is a region of mostly calm weather at the center of strong tropical cyclones. The eye of a storm is a roughly circular area, typically 30–65 km (20–40 miles) in diameter. It is surrounded by the eyewall, a ring of towering thunderstorms where the most severe weather and highest winds occur. The cyclone's lowest barometric pressure occurs in the eye and can be as much as 15 percent lower than the pressure outside the storm.
On June 14 at 21:00 UTC, the government of Mexico issued a tropical storm watch for Tecpan de Galeana to Punta Maldonado. Six hours later, the watch was upgraded to a tropical storm warning. On June 15 at 15:00 UTC, the tropical storm warning was extended to Lagunas de Chacahua. Six hours later, the warning was discontinued for Tecpan de Galeana to west of Acapulco. On June 17 at 03:00 UTC, the warning was extended westward from Acapulco to Tecpan de Galeana and cancelled to the east of Punta Maldonado. At 09:00 UTC, the warning was discontinued east of Tecpan de Galeana and extended westward to Lazaro Cardenas. The tropical storm warning was cancelled at 18:00 UTC, after Carlotta weakened into a tropical depression.
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is within about 1 second of mean solar time at 0° longitude, and is not adjusted for daylight saving time. In some countries where English is spoken, the term Greenwich Mean Time (GMT) is often used as a synonym for UTC and predates UTC by nearly 300 years.
Tropical Storm Carlotta caused flooding in southern Mexico, with the states of Aguascalientes, Guerrero, Michoacán, Oaxaca, Puebla, and the Yucatán Peninsula being affected. Additionally, Carlotta caused two deaths in Aguascalientes and one in Oaxaca. In the Yucatán Peninsula, Carlotta, a tropical wave, and another low-pressure system dropped between 70–400 mm (3–20 in) of rain, causing severe flooding. In Tizimín, the Popolnáh police station was inundated and the DN-III-E Plan, a plan for the coordination of search and rescue operations and disaster aid, was activated to help with recovery efforts.
Michoacán, formally Michoacán de Ocampo, officially the Free and Sovereign State of Michoacán de Ocampo, is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. The State is divided into 113 municipalities and its capital city is Morelia. The city was named after José María Morelos, one of the main heroes of the Mexican War of Independence.
Puebla, officially the Free and Sovereign State of Puebla is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 217 municipalities and its capital is the city of Puebla.
The Yucatán Peninsula, in southeastern Mexico, separates the Caribbean Sea from the Gulf of Mexico, with the northern coastline on the Yucatán Channel. The peninsula lies east of the Isthmus of Tehuantepec, a northwestern geographic partition separating the region of Central America from the rest of North America. It is approximately 181,000 km2 (70,000 sq mi) in area, and is almost entirely composed of limestone.
In Oaxaca, severe flooding killed one individual. Fishermen recovered the body of a 29-year-old man about 10 mi (20 km) off the coast after he was dragged away by flood waters and drowned. The proximity of Carlotta prompted the closure of the ports of Huatulco, Puerto Ángel, and Puerto Escondido and the suspension of fishing operations. Additionally, multiple landslides occurred in the state. In Guerrero, only minor damage occurred. In the Costa Chica region, the storm damaged several palapas on a beach and the fishing equipment of at least 80 families, preventing them from working. In the municipalities of Tecpan de Galeana, Zihuatanejo, and Petatlán, 42 homes were inundated by flood waters. A total of 138 trees were downed in Acapulco and several other municipalities. In Acapulco, a hospital sustained damage to its windows and four injuries were reported. Additionally, 32 neighborhoods lost power, nine houses lost their roofs, and 11 roads collapsed. In Tehuacán, Puebla, homes and businesses flooded, multiple cars were stranded, and several trees fell. Additionally, a state highway and a bridge collapsed, cutting off several towns in the area.
In Michoacán, multiple cities along the coast experienced severe flooding. In Melchor Ocampo, a peak rainfall total of 285.0 mm (11.2 in) occurred. Approximately 210.6 mm (8.291 in) of rain fell in La Villita while 194.9 mm (7.673 in) was recorded in Presa La Villita. Rainfall caused the Acalpican River to overflow its banks. In the Tiquicheo Municipality, 10 houses flooded after a river near the city overflowed its banks. Additionally, multiple homes were inundated in the Zamora Municipality. In Pátzcuaro, multiple landslides occurred, damaging roads in the region. In Nuevo Urecho, the overflow of the Los Hervores River damaged water pumps, resulting in a water shortage throughout the municipality. Throughout the storm, 35 temporary shelters were in operation in Michoacán.
In Aguascalientes, Carlotta caused infrastructural damage and two indirect deaths in Aguascalientes City. Rainfall from Carlotta flooded streets, sweeping away dozens of cars and prompting the rescue of several people. Two women became entrapped in their vehicle due to rising flood waters and died of carbon monoxide poisoning. 57 mm (2.2 in) of rain fell, the city's drainage system collapsed. Moreover, 12 trees fell and 12 houses were flooded. Additionally, a waterspout touched down in the state. Mexican authorities alerted the public that the El Cedazo dam had the potential to overflow due to the heavy rainfall, although no overflow actually occurred.After
The 1989 Atlantic hurricane season was an average season with 11 named storms. The season officially began on June 1, and ended on November 30. The first storm, Tropical Depression One, developed on June 15, and dissipated two days later without effects on land. Later that month, Tropical Storm Allison caused severe flooding, especially in Texas and Louisiana. Tropical Storm Barry, Tropical Depressions Six, Nine, and Thirteen, and Hurricanes Erin and Felix caused negligible impact. Hurricane Gabrielle and Tropical Storm Iris caused light effects on land, with the former resulting in nine fatalities from rip currents offshore the East Coast of the United States and Atlantic Canada, while the latter produced minor flooding in the United States Virgin Islands.
The 2007 Pacific hurricane season was a below-average Pacific hurricane season, featuring one major hurricane. The season officially started on May 15 in the eastern Pacific and on June 1 in the central Pacific, and ended on November 30; these dates conventionally delimit the period during which most tropical cyclones form in the region. The first tropical cyclone of the season, Alvin, developed on May 27, while the final system of the year, Kiko, dissipated on October 23. Due to unusually strong wind shear, activity fell short of the long-term average, with a total of 11 named storms, 4 hurricanes, and 1 major hurricane. At the time, 2007 featured the second-lowest value of the Accumulated cyclone energy (ACE) index since reliable records began in 1971. Two tropical cyclones – Cosme and Flossie – crossed into the central Pacific basin during the year, activity below the average of 4 to 5 systems.
The 2006 Pacific hurricane season was the most active since the 2000 season, producing produced 21 tropical depressions; 19 of which became tropical storms or hurricanes. The season officially started on May 15, 2006 in the eastern Pacific, designated as the area east of 140°W, and on June 1, 2006 in the central Pacific, which is between the International Date Line and 140°W, and lasted until November 30, 2006. These dates typically limit the period of each year when most tropical cyclones form in the eastern Pacific basin. This timeline documents all the storm formations, strengthening, weakening, landfalls, extratropical transitions, as well as dissipation. The timeline also includes information which was not operationally released, meaning that information from post-storm reviews by the National Hurricane Center, such as information on a storm that was not operationally warned on, have been included.
Tropical Storm Julio in 2002 was a weak and short-lived tropical storm that made landfall along the southern Mexican coast. An area of convection organized into a tropical depression on September 25. Initially forecast to stay offshore, the depression headed northward and strengthened into a tropical storm that same day. Julio turned to the northwest and peaked as a minimal tropical storm just before landfall near Lázaro Cárdenas, on September 26. The storm soon weakened into a tropical depression and later on September 26, it rapidly dissipated over Mexico.
Tropical Storm Carlos was the first of five tropical cyclones to make landfall during the 2003 Pacific hurricane season. It formed on June 26 from a tropical wave to the south of Mexico. It quickly strengthened as it approached the coast, and early on June 27 Carlos moved ashore in Oaxaca with winds of 65 mph (100 km/h). The storm rapidly deteriorated to a remnant low, which persisted until dissipating on June 29. Carlos brought heavy rainfall to portions of southern Mexico, peaking at 337 mm (13.3 in) in two locations in Guerrero. Throughout its path, the storm damaged about 30,000 houses, with a monetary damage total of 86.7 million pesos. At least nine people were killed throughout the country, seven due to mudslides and two from river flooding; there was also a report of two missing fishermen.
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The 2014 Pacific hurricane season was the fifth-busiest season since reliable records began in 1949, alongside the 2016 season. The season officially started on May 15 in the East Pacific Ocean, and on June 1 in the Central Pacific; they both ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the Pacific basin.
Hurricane Adrian was an intense, albeit short-lived early-season category 4 hurricane that took part during the 2011 Pacific hurricane season. Adrian originated from an area of disturbed weather which had developed during the course of early June, off the Pacific coast of Mexico. On June 7, it acquired a sufficiently organized structure with deep convection to be classified as a tropical cyclone, and the National Hurricane Center (NHC) designated it as Tropical Depression One-E, the first one of 2011. It further strengthened to be upgraded into a tropical storm later that day. Adrian moved rather slowly; briefly recurving northward after being caught in the steering winds. After steady intensification, it was upgraded into a hurricane on June 9. The storm subsequently entered a phase of rapid intensification, developing a distinct eye with good outflow in all quadrants. Followed by this period of rapid intensification, it obtained sustained winds fast enough to be considered a major hurricane and reached its peak intensity as a category 4 hurricane that evening.
The 2012 Pacific hurricane season was an above-average year in which seventeen named storms formed. The hurricane season officially began on May 15 with the formation of Tropical Storm Aletta in the East Pacific—defined as the region east of 140°W—and on June 1 in the central Pacific—defined as the region west of 140°W to the International Date Line—and ended on November 30 in both basins. These dates conventionally delimit the period during each year when most tropical cyclones form. The final cyclone of the year, Tropical Storm Rosa, dissipated on November 3.
Hurricane Carlotta was the easternmost tropical cyclone in the Eastern Pacific to make landfall at hurricane intensity since 1966. The third tropical cyclone and third named storm of the 2012 Pacific hurricane season, Carlotta developed slowly into a tropical depression from a tropical wave southwest of Central America on June 14. It moved generally west-northwestward and by the following day, strengthened into tropical storm strength. Thereafter, gradual intensification occurred and the storm reached hurricane strength on June 15. Rapid intensification ensued further, as Carlotta peaked as a 110 mph (175 km/h) Category 2 hurricane on the same day. At 0100 UTC the following day, Carlotta made landfall near Puerto Escondido, the easternmost landfalling Pacific hurricane in recorded history at the time. The next day the storm began to weaken as it moved onshore Southwestern Mexico. Carlotta continued to weaken rapidly, eventually dissipating on June 16.
Hurricane Raymond was the only major hurricane in the eastern Pacific in 2013 and briefly threatened the southwestern coast of Mexico before recurving back out to sea. The seventeenth named storm and eighth hurricane of the annual cyclone season, Raymond developed from a tropical wave on October 20 south of Acapulco, Mexico. Within favorable conditions for tropical cyclone development, Raymond quickly intensified, attaining tropical storm intensity and later hurricane intensity within a day of cyclogenesis. On October 21, the hurricane reached its peak intensity with winds of 125 mph (205 km/h). A blocking ridge forced the hurricane to the southwest, while at the same time Raymond began to quickly weaken due to wind shear. The following day, the tropical cyclone weakened to tropical storm status. After tracking westward, Raymond reentered more favorable conditions, allowing it to intensify back to hurricane strength on October 27 while curving northward. The hurricane reached a secondary peak intensity with winds of 105 mph (165 km/h) several hours later. Deteriorating atmospheric conditions resulted in Raymond weakening for a final time, and on October 30, the National Hurricane Center (NHC) declared the tropical cyclone to have dissipated.
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Hurricane Rosa was the first tropical cyclone to make landfall in the Mexican state of Baja California since Nora in 1997. The seventeenth named storm, tenth hurricane, and seventh major hurricane of the 2018 Pacific hurricane season, Rosa originated from a broad area of low pressure that the National Hurricane Center began monitoring on September 22. The disturbance moved westward and then west-northwestward for a few days, before developing into a tropical depression on September 25. Later that day, the depression strengthened into Tropical Storm Rosa. One day later, Rosa became a hurricane. On September 27, Rosa began a period of rapid intensification, ultimately peaking as a Category 4 hurricane with maximum sustained winds of 150 mph and a minimum central pressure of 936 mbar on the next day. Over the next couple of days, Rosa turned towards the northeast. By September 29, Rosa had weakened into a Category 2 hurricane due to ongoing structural changes and less favorable conditions. Later on the same day, Rosa re-intensified slightly. On September 30, Rosa resumed weakening as its core structure eroded. Early on October 1, Rosa weakened into a tropical storm. On October 2, Rosa weakened to a tropical depression and made landfall in Baja California. Later in the day, Rosa's remnants crossed into the Gulf of California, with its surface and mid-level remnants later separating entirely. The mid-level remnants of Rosa continued to travel north, reaching northeast Arizona late in the day. On October 3, Rosa's remnants were absorbed into an upper-level low situated off the coast of California.
Tropical Storm Vicente was a weak and small tropical cyclone affected the southwestern Mexico in late October 2018, causing deadly flooding and mudslides. The twenty-first named storm of the 2018 Pacific hurricane season, Vicente originated from a trough of low pressure that formed within a large area of disturbed weather near Central America early on October 19. Around midday, the disturbance organized into a tropical depression, which prompted the National Hurricane Center to begin issuing advisories. Later in day, the depression strengthened into a tropical storm and was assigned the name Vicente. Despite having only been a weak tropical storm, Vicente developed an intermittent eye-like feature. Unfavorable conditions prevented strengthening until late on October 20. At that time, Vicente peaked with maximum sustained winds of 50 mph and a minimum central pressure of 1002 mbar. A day later, Vicente began to weaken due increasing wind shear before slightly restrengthening early on October 22. On October 23, Vicente weakened into a tropical depression. Later in the day, Vicente degenerated into a remnant low after making landfall in southwestern Mexico, before dissipating soon afterward.
Tropical Storm Ileana was a tropical cyclone that affected Western Mexico, causing multiple deaths and flooding. The ninth named storm of the 2018 Pacific hurricane season, Ileana originated from a tropical wave that the National Hurricane Center began monitoring on July 26 as it left the west coast of Africa. The wave travelled across the Atlantic Ocean with no thunderstorm activity, before crossing into the Eastern Pacific Ocean on August 4. The disturbance quickly and unexpectedly organized into a tropical depression later in the day. Initially, the depression was well defined, but it soon degraded due to unfavorable conditions. It began to strengthen on August 5, becoming Tropical Storm Ileana. On August 6, Ileana peaked with winds of 65 mph (100 km/h) and a pressure of 998 mbar. Ileana began to develop an eyewall structure soon after, but became intertwined with nearby Hurricane John. John disrupted Ileana and ultimately absorbed it on August 7.
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