The 2021 Pacific hurricane season was a moderately active Pacific hurricane season, with above-average activity in terms of number of named storms, but below-average activity in terms of major hurricanes,[nb 1] as 19 named storms, 8 hurricanes, and 2 major hurricanes formed in all.[nb 2][2] It also had a near-normal accumulated cyclone energy (ACE). The season officially began on May15, 2021 in the Eastern Pacific Ocean (east of from 140°W), and on June1, 2021, in the Central Pacific (from 140°W to the International Date Line) in the Northern Hemisphere. The season ended in both regions on November30, 2021. These dates historically describe the period each year when most tropical cyclogenesis occurs in these regions of the Pacific and are adopted by convention.[3] However, the formation of tropical cyclones is possible at any time of the year, as illustrated by the formation of Tropical Storm Andres on May 9, which was the earliest forming tropical storm on record in the Eastern Pacific. Conversely, 2021 was the second consecutive season in which no tropical cyclones formed in the Central Pacific.
In June, Tropical Storm Dolores made landfall near the border of the Mexican states of Colima and Michoacán, killing three people and resulting in US$50 million[nb 3] in insured losses. Just a week later, Hurricane Enrique paralleled the west coast of Mexico, causing an additional two fatalities and a similar amount of damage. In August, Hurricane Nora made landfall on the state of Jalisco and paralleled the Pacific coast of Mexico until dissipating, resulting in an estimated $100 million in damage and three more deaths. Less than two weeks later, Hurricane Olaf made landfall on Baja California Sur as a Category 2 hurricane. In October, Hurricane Pamela struck Nayarit at Category 1 intensity, leaving four people missing and severe flooding. Later that month, Hurricane Rick struck near the Michoacán-Guerrero border at peak intensity as a strong Category 2 hurricane. Altogether, five systems made landfall in Mexico in 2021, the greatest number since 2018.[2]
Forecasts include weekly and monthly changes in important factors that help determine the number of tropical storms, hurricanes, and major hurricanes within a particular year. According to the National Oceanic and Atmospheric Administration (NOAA), the average hurricane season in the Eastern and Central Pacific between 1991 and 2020 contained approximately 15 tropical storms, 8 hurricanes, and 4 major hurricanes. The NOAA generally classifies a season as above average, average, or below average based on the cumulative ACE index, but occasionally the number of tropical storms, hurricanes, and major hurricanes within a hurricane season is also considered. Factors they expected to reduce activity were near- or below-average sea surface temperatures across the eastern Pacific and the El Niño–Southern Oscillation remaining in the neutral phase, with the possibility of a La Niña developing.[7]
On May 12, 2021, the Servicio Meteorológico Nacional issued its forecast for the season, predicting a total of 14–20 named storms, 7–10 hurricanes, and 4–5 major hurricanes to develop.[6] On May 20, 2021, the National Oceanic and Atmospheric Administration (NOAA) issued their outlook, calling for a below-normal to near-normal season with 12–18 named storms, 5–10 hurricanes, 2–5 major hurricanes, and an accumulated cyclone energy index of 65% to 120% of the median.
Three tropical cyclones present in the East Pacific simultaneously on August 2. From right to left; Ignacio, Hilda, and a disturbance that would eventually become Jimena.
The 2021 Pacific hurricane season began on May15 in the East Pacific and on June1 in the Central Pacific.[8] Overall activity included 19 named storms, 8 hurricanes, and 2 major hurricanes. The total of named storms was above the 1991–2020 average, while the number of hurricanes was average, and the sum of major hurricanes was below average.[9] The official start date was preceded by the formation of Tropical Storm Andres, the earliest named storm on record in the East Pacific.[10] It was accompanied by Tropical Storm Blanca later in May.[11] The following month included the formations of tropical storms Carlos and Dolores, in addition to Hurricane Enrique. While Carlos remained away from land, Dolores made landfall on the Mexico coastline and Enrique delivered impacts across southwestern sections of the country while it passed just offshore.[12] Above-average seasonal activity continued into July with the development of hurricanes Felicia and Hilda, Tropical Storm Guillermo, and Tropical Depression Nine-E; none of these cyclones impacted land.[13] In August, Hurricane Nora made landfall along the west-central coastline of Mexico. Its formation was preceded by Hurricane Linda and tropical storms Ignacio, Kevin, and Marty, which did not impact land.[14] September marked a stark turn around to the activity of the previous months, as it only featured Olaf, which struck San José del Cabo as a Category2 hurricane.[15] Two hurricanes – Pamela and Rick – moved ashore the Mexico coastline in October.[16] An additional two storms, Terry and Sandra, developed in November, the fourth consecutive November with at least one named storm. Furthermore, those cyclones existed simultaneously, the first occurrence in the East Pacific during November on record. The Accumulated Cyclone Energy index for the 2021 Pacific hurricane season as calculated by Colorado State University using data from the National Hurricane Center was approximately 94units,[nb 4][17] about 30 percent below average.[9]
In early May, the passage of a convectively-coupled kelvin wave (CCKW) enhanced the eastern Pacific monsoon trough, leading to an area of disturbed weather. This disturbance interacted with a Gulf of Tehuantepec gap wind event, which led to the formation of an ill-defined low-pressure area. Despite a marginal environment of wind shear and dry air, the system slowly organized and developed into a tropical depression around 06:00UTC on May9. Six hours later, it intensified into Tropical Storm Andres, becoming the earliest tropical storm on record in the East Pacific basin. Andres maintained peak winds of 40mph (65km/h) as it curved north-northwest, and the compounded effects of colder waters and drier air atop moderate wind shear instead caused the system to begin weakening. All associated convective activity dissipated by 06:00UTC on May11, when Andres was downgraded to a remnant area of low pressure. The low curved west on May12 and dissipated later that day.[10]
There are no reports of damage or casualties directly associated with Tropical Storm Andres; however, some other rainstorms associated with Andres produced heavy rainfall in Southwestern Mexico.[18][19][20] Moisture from the storm caused intense rain and even a hailstorm as far east as the State of Mexico, including in the state's capital, Toluca.[20] Vehicles became stranded in floods, some small trees got knocked over, and about 50 houses were damaged by a flooding river.[21][22] Four municipalities in the Toluca Valley were flooded; 30 cars were stranded in a flooded parking lot of a church in Metepec, and in Lerma, a shopping center's roof was damaged due to flying debris and hail.[23]
Blanca originated from a tropical wave that crossed Central America on May27. Shower and thunderstorm activity increased ahead of the wave axis, followed by the formation of a low-pressure area. After further organization, the developed into a tropical depression around 18:00UTC on May30. It intensified into Tropical Storm Blanca around 12:00UTC the next day. Favorable environmental conditions allowed the cyclone to intensify, and it attained peak winds of 60mph (95km/h) on June1 when prominent rainbands wrapped into the center. Thereafter, an upper-level trough off the southwestern United States increased shear over Blanca and injected dry air into the core, resulting in a weakening trend. The storm's low-level circulation became separated from convection, and it degenerated to a remnant low by 00:00UTC on June4. The remnants of Blanca, which were previously tracking west-northwest, curved toward the west before dissipating later the next day.[24]
A trough developed within the Intertropical Convergence Zone (ITCZ) on June1. It moved west across the eastern Pacific for several days but failed to develop into a tropical cyclone on several occasions, either because it lacked a coherent circulation or because it lacked sustained convection. A burst of thunderstorms resulted in the formation of a well-defined center on June12, and the system steadily organized over ensuing hours, finally resulting in the formation of a tropical depression by 12:00UTC that day. Six hours later, the depression intensified into Tropical Storm Carlos to the southwest of Baja California Sur. The surrounding environment was initially favorable for development and allowed the system to reach peak winds of 50mph (85km/h) as it curves west-southwest. However, increasing dry air around the storm caused Carlos to gradually lose its convection, which ultimately resulted in its degradation to a remnant low by 12:00UTC on June16. The remnant system was reabsorbed into the ITCZ the following day.[25]
A broad cyclonic gyre over Central America, spawned from the interaction of the monsoon trough and a tropical wave, led to the formation of an area of low pressure south of Mexico on June16. The low gradually organized and became a tropical depression around 18:00UTC on June17 while located about 195mi (315km) south-southwest of Acapulco. The depression became Tropical Storm Dolores within six hours. Ridging over Mexico shifted east as Dolores developed, causing the cyclone to curve to the north-northwest. A favorable environment facilitated its development, and the storm reached peak winds of 70mph (110km/h) as it made landfall near San Juan de Alima, Michoacán, around 15:00UTC on June19. It harbored a well-defined eyewall at the time, and it is possible that Dolores temporarily surpassed tropical storm intensity. Once inland, though, the system quickly weakened over the high terrain of southwestern Mexico, dissipating around 06:00UTC on June20.[26]
Dolores produced a wide expanse of 5in (130mm) or greater rainfall across southwestern Mexico, including a peak accumulation of 17.31in (440mm) in Callejones, Colima. At least 20 municipalities in Michoacán were affected by flooding or uprooted trees, blocking many routes through these communities. In Jalisco, the Marabasco River overflowed its banks, briefly isolating 80 homes. Throughout Guerrero, Michoacán, Colima, and Jalisco, more than 50,000 customers lost power. Overall damage to more than 1,000 structures totaled in excess of $50 million. Three people were killed by lightning, two in Oaxaca and one in Jalisco.[26]
A tropical wave left Africa on June14 and crossed Central America a week later. The system coalesced as it moved south of Mexico, becoming Tropical Storm Enrique by 12:00UTC on June25 since the incipient system was already producing gale-force winds at the time of development. Moderate wind shear initially inhibited the cyclone, but these unfavorable winds slackened late on June25, allowing the cyclone to begin a 24-hour period of rapid intensification. Enrique intensified into a hurricane around 12:00UTC on June26 and reached peak winds of 90mph (150km/h) the next morning as it was characterized by a cloud-filled eye. The storm curved north and then bent back northwest, passing within 45miles (75km) of the Mexico coastline. Dry air off the mountainous terrain of that country, and later colder waters, soon caused Enrique to lose organization. By 18:00UTC on June30, the increasingly disheveled circulation was absorbed into a broad trough east of Baja California.[27]
Two people died from rip currents in Pie de la Cuesta, Guerrero.[28] At least 207 homes were damaged by landslides and winds caused by Enrique in Guerrero.[29] In Lázaro Cárdenas, Michoacán, areas were inundated by more than 50cm (19in) of floodwater.[30] A total of 115,904 customers lost power across Jalisco, although 96% of homes returned with power a couple of hours later.[31] A citywide power outage also occurred in Tepic.[32]
A disturbance of unclear origin was identified over Central America and the far eastern Pacific on July9. The system progressed westward over the open ocean during the following days, developing into a tropical depression around 00:00 UTC on July14 and becoming Tropical Storm Felicia six hours later. Felicia immediately underwent rapid intensification, becoming a hurricane by 06:00 UTC on July15 and a major hurricane 24hours later. Early on July17, the system attained peak winds of 145mph (235km/h).[33] At that time, Felicia displayed a warm eye encapsulated by a ring of −70°C (−94°F) convection and little additional rainbands outside the eyewall, a signature sign of an annular tropical cyclone.[34] It was also a very small storm, with hurricane-force winds extending only 15miles (25km) from the center. After a brief westward turn, Felicia resumed a west-northwestward motion into much more hostile environmental conditions on July18. The cyclone rapidly weakened and degenerated to a remnant low by 18:00UTC on July20 while located well east of Hawaii. Low-level wind flow steered the remnant low of Felicia to the west-southwest, and it opened into a trough two days later.[33]
A tropical wave moved off the coast of Africa on July6 and emerged into the eastern Pacific basin a week later, where the background environment already favored cyclonic spin. Consequently, a disturbance spawned along the wave axis developed into a tropical depression by 00:00UTC on July17 and further into Tropical Storm Guillermo within twelve hours. A potent ridge pushed the cyclone west-northwest, while a favorable combination of low wind shear and very warm ocean temperatures allowed it to intensify. Guillermo reached peak winds of 60mph (95km/h) on July18 despite a slightly less organized satellite appearance. Around this time, the storm produced tropical storm-force gusts on Socorro and Clarion islands. After its peak, Guillermo encountered cooler waters and higher wind shear, which ultimately caused it to degenerate to a remnant low by 00:00UTC on July20. The low moved faster to the west-southwest before it was absorbed by a trough a day later far away from land.[35]
On July 24, a disturbance formed near south of Gulf of Tehuantepec, which was moving parallel offshore of southern Mexico.[36] As it moved farther from the coast of Mexico, the disturbance gradually became organized, and on July 28, a low pressure area formed,[37] as satellite imagery showed that the associated shower activity was showing signs of organization.[38] The low-pressure area further organized, with a pair of ASCAT passes showing that the low-pressure area had strengthened significantly and was producing tropical storm-force winds, with the circulation looking well-defined on satellite imagery. On July 30, it was designated as a tropical storm.[39] Hilda intensified to a high-end tropical storm a day later as a central dense overcast developed.[40] Later, Hilda further intensified to a hurricane as a short-lived eye appeared in its central dense overcast.[41] Hilda held a similar appearance the next day, with its center located north of its central dense overcast.[42] Hilda briefly developed a closed mid-level eye the next day, though the low-level and mid-level centers were not stacked due to wind shear.[43] However, it became less organized later that day, with a less distinct eye and an incomplete eyewall.[44] By the next day, Hilda was downgraded to a high-end tropical storm since the eyewall was no longer well-defined, while convection continued to pulse in the southern semicircle.[45] Deep convection continued to wane due to shear, cooler waters, and more stable air.[46] By August 5, Hilda weakened into a tropical depression after a rapid weakening of convection near the center. However, convection resumed pulsing later.[47] On August 6, at 03:00 UTC, Hilda became a post-tropical cyclone, as it became devoid of deep convection due to sub-23°C (73°F) sea-surface temperatures.[48][49]
On July 26, the NHC noted a disturbance located about 700 miles (1,125km) south-southwest of the southern tip of Baja California. The system moved parallel to another disturbance which later became Hurricane Hilda.[50] By 21:00 UTC on July 30, the disturbance attained a well-defined center of circulation with sufficient organized convection and was classified as a tropical depression, bearing the designation Nine-E.[51] The depression was initially forecast to become a tropical storm, but failed to do so due to dry air and wind shear caused by nearby Hurricane Hilda. Early on August 1, the system degenerated into a remnant low.[52] Even though Nine-E was a tropical low, the NHC still monitored the system for further development[53] On August 4, it re-intensified into a tropical depression again while maintaining two rainbands in a slightly elongated circulation.[54] On the next day, at 09:00 UTC, the depression intensified into a tropical storm, with the NHC naming it as Jimena, as the storm's deep convection had increased near the low-level center and based on satellite imagery, the storm was producing tropical storm force winds.[55] The convection later diminished on August 6, as it moved over cooler sea-surface temperatures and encountering high wind shear and dry airmass. However, despite all this, Jimena managed its intensity, as it continued to produce tropical storm force winds, based on ASCAT data.[56] A deep convective mass also continued to persist over the center of Jimena.[57] At 21:00 UTC, the NHC issued its last advisory, downgrading the system to a tropical depression as it entered the CPHC's area of responsibility. Its deep convection weakened significantly as it moved over cool sea surface temperatures causing Jimena to weaken.[58] The CPHC later issued its only bulletin for Jimena at 03:00 UTC the next day, stating that Jimena had become a post-tropical cyclone as its deep convection had collapsed completely.[59]
A parade of tropical waves entered the eastern Pacific in late July. By 12:00UTC on August1, one wave spawned a disturbance that had gained sufficient organization to be designated a tropical depression. Moderately wind shear inhibited the newly formed system, and though it intensified into Tropical Storm Ignacio a day later, the system failed to organize beyond that strength as its low-level circulation became separated from associated convective activity. Around this time, the system produced tropical storm-force gusts on Socorro Island. Later on August2, Ignacio began to succumb to increasingly dry air and cooler waters. It degenerated to a remnant low around 00:00UTC on August4, which moved erratically until it dissipated southwest of Baja California twelve hours later.[60]
A tropical wave entered the eastern Pacific on August1, and the resultant disturbance organized into a tropical depression around 12:00UTC on August7. The newly formed cyclone swiftly intensified amid very high mid-level moisture and ocean temperatures, becoming Tropical Storm Kevin six hours later and reaching peak winds of 65mph (100km/h) on August8. Wind shear abruptly increased later that day, confining the storm's convection into the western semicircle. Kevin passed near Clarion Island on August10 as it moved west then west-northwest, producing tropical storm-force gusts there. By 12:00UTC on August12, all associated convection dissipated, and the system degenerated to a remnant low. The low curved northwest and dissipated west of Baja California Sur on August15.[61]
A tropical wave moved into the eastern Pacific on August6, spawning an area of disturbed weather that subsequently became a tropical depression around 06:00UTC on August10. It moved generally westward, intensifying into Tropical Storm Linda six hours later and organizing further beyond that point, but temporarily succumbing to some dry air and wind shear. As those factors subsided, Linda strengthened into a hurricane on August12 and soon began rapidly intensifying over warm ocean waters, a process that culminated in it becoming the season's second and final major hurricane by 18:00UTC on August13. The next day, Linda peaked as a Category4 cyclone with winds of 130mph (215km/h). Between August14–15, the storm underwent an eyewall replacement cycle. Much like Hurricane Felicia, Linda soon acquired characteristics of an annular hurricane, with a 45mi (75km) wide eye surrounded by deep, symmetric convection and little additional banding. The hurricane fluctuated in intensity over the next few days as it moved over varying ocean temperatures and through drier air. Late on August18, Linda progressed over ocean waters cooler than 26°C (79°F), which led to rapid weakening. The system ultimately degenerated to a gale-force remnant low by 18:00UTC on August19. It later crossed into the Central Pacific basin.[62]
The remnant low later traversed Hawaii on August22–23, dropping 2 to 7in (51 to 178mm) of rain across several islands. The greatest rainfall totals were: 7.12in (181mm) at Mount Waialeale, Kauai, and 7.10in (180mm) at Manoa Lyon Arboretum, Oahu. Oahu was also buffeted by winds in excess of 30mph (45km/h) on August23, with a peak gust of 56mph (90km/h) recorded near Kaena Point.[63]
The Atlantic's Hurricane Grace struck mainland Mexico as a Category3 hurricane on August21. Although that storm's low-level center dissipated over the mountainous terrain of Mexico, its mid-level circulation emerged into the eastern Pacific and soon became encompassed by deep convection. That thunderstorm activity spawned a new surface center separate from Grace's previous one, and further organization of the disturbance led to the formation of Tropical Storm Marty by 00:00UTC on August23. The newly christened tropical storm reached peak winds of 45mph (75km/h) early on August23, but it began to weaken shortly thereafter as wind shear increased. Marty moved west as it encountered an increasingly hostile environment of dry air and cooler waters, resulting its degeneration to a remnant low by 06:00UTC on August24. Three days later, it dissipated into a trough well to the west-southwest of Baja California Sur.[64]
On August 19, an area of disturbed weather formed west of the southern Mexico coast, which was producing disorganized thunder storms.[65] A day later, the system became better defined and signs of the organization of showers and thunderclouds were also noted.[66] On August 25, at 11:00 UTC the system developed a well-defined circulation as a scatterometer pass showed that it was producing near tropical storm-force winds. Thus, the NHC designated the system as Tropical Depression Fourteen-E.[67] A day later at 17:00 UTC, Fourteen-E intensified into a tropical storm, with the NHC naming it as Nora as its deep convection had organized significantly along with improved curvature of its bands.[68] On August 28, at 11:00 UTC, Nora intensified into a Category 1 hurricane, as its inner core structure became further defined with the formation of a low-level eyewall.[69] Nora made landfall on Jalisco, after which it skirted the coasts of Nayarit and Sinaloa as a weakening storm and rapidly dissipated on August 30 as it moved further inland. It brought considerable damage to Mexico, killing two people and leaving six missing due to a landslide in Cabo Corrientes.[70][71] It had also caused flooding and mudslides. The damage caused by the passage through Nora to the country reached 200 million pesos (US$10 million).[72] Nora's remnants caused heavy rain in Arizona,[73]Colorado, and Utah.[74]
A tropical wave moved off Africa on August22. It fractured twice over subsequent days, with portions of the original wave axis spawning tropical storms Kate and Mindy in the Atlantic. The southern piece of the wave continued into the East Pacific on September2, where it led to the formation of a new tropical depression around 18:00UTC on September7 about 230mi (370km) west-southwest of Manzanillo, Colima. The system drifted toward the northwest in weak steering currents, while favorable environmental parameters allowed it to intensify. The depression became Tropical Storm Olaf around 12:00UTC on September8, and Olaf became a hurricane 24hours later. The cyclone's eye and overall presentation continued to improve into September10, and Olaf reached its peak as a Category2 hurricane with winds of 105mph (165km/h) at 02:50UTC that day. It concurrently made landfall near San Jose del Cabo, Baja California Sur. The storm only slowly weakened over land, but this process accelerated as it continued into stable air offshore. It curved west and degenerated to a remnant low around 06:00UTC on September11. The low continued in that direction for another day before dissipating.[75]
As Olaf paralleled the Mexico coastline, it produced rainfall totals up to 4in (100mm) across Jalisco, which resulted in localized flooding. One man died there following a mudslide. Rainfall accumulations were generally similar across the Baja California Peninsula, though a peak value of 9.27in (235mm) was observed in El Triunfo. Many weather stations near Olaf's landfall location lost power upon the storm's final approach, but widespread tropical storm-force winds were nevertheless recorded. The strong winds damaged hotels, uprooted trees, and downed power lines. More than 190,000customers across the Baja California Peninsula were without power at the height of the storm. Total damage was estimated at $10million, primarily focused in La Paz and Los Cabos.[75]
A tropical wave emerged into the eastern Pacific on October8, and it swiftly organized into a tropical depression by 06:00UTC on October10. The system moved west-northwest, tracking parallel to the Mexico coastline initially after formation, and intensified into Tropical Storm Pamela six hours later.[76] Throughout Pamela's duration, the NHC highlighted the expectation of a potentially major hurricane rapidly intensifying up to the Mexico coastline.[77] Despite these projections, the storm suffered first from moderate northerly wind shear and later from dry air intrusions, which caused the storm to fluctuate in intensity over the coming days. It became a hurricane around 06:00UTC on October12, weakened thereafter, and regained hurricane strength early the next day. Pamela maintained winds of 75mph (120km/h) as it recurved northeast ahead of a broad upper-level trough, and it made landfall at that intensity just north of Mazatlán, Sinaloa, at 12:30UTC on October13. Topographical and environmental effects caused Pamela to rapidly dissipate shortly before 00:00UTC on October14 over northern Mexico.[76]
Although Pamela made landfall in a remote location, its effects were spread across large portions of northwestern Mexico. Across Colima and Nayarit, widespread rainfall accumulations of 4–8in (100–200mm) – with isolated totals up to 12in (300mm) – caused widespread flooding.[76] Numerous local communities were inundated or isolated,[78] with individuals stranded and highways collapsed.[79][80] Crops suffered heavy losses.[81] Gusty winds across Sinaloa damaged structures, either directly or from the uprooting of many trees.[82] Across the Southern United States, the remnants of Pamela combined with a cold front, leading to a widespread area of 3–6in (76–152mm) rainfall totals, with locally higher amounts. Three people were killed as a result of Pamela, two in Texas when vehicles fell off a bridge into the Martinez Creek near San Antonio and one in Nayarit when one person was swept away into the Acaponeta River.[76][80]
A collection of convection formed over Colombia, Panama, and adjacent waters of the Caribbean and East Pacific on October16. The disturbance moved west without much change in organization until it developed into a tropical depression early on October22. The system strengthened into Tropical Storm Rick within six hours of formation and continued to intensify amid very favorable environmental conditions as it moved generally north-northwest. Rick became a hurricane early on October23, around which time the system developed a pinhole eye in microwave imagery. After reaching winds of 90mph (150km/h), the system abruptly weakened as its inner core structure eroded. However, the cyclone soon developed a large eye, and it reached a peak intensity of 105mph (165km/h) early on October25. Rick maintained these winds as it made landfall in La Unión de Isidoro Montes de Oca, Guerrero, around 11:00UTC. The storm weakened rapidly once inland and dissipated before 00:00UTC on October26.[83]
Rick produced at least 4in (100mm) of rain across coastal sections of Guerrero and Michoacán, with a peak accumulation of 11.06in (281mm) in Petacalco and Coyuquilla in Guerrero. These rains prompted flash flooding that stranded cars and caused damage throughout the region, even well inland across the state of Morelos where one man was killed in Tepoztlán. Four rivers and streams overrun their banks across Zihuatanejo and Tecpan de Galeana, including the Petatlán River which cut off the Acapulco–Zihuatanejo federal highway. Many large trees were uprooted and some damage occurred to buildings between Ixtapa and Lázaro Cárdenas. Rick prompted the evacuation of 402people and damaged 1,277houses across 11states and 700municipalities. Nearly 184,000 homes lost power, especially concentrated in the states of Michoacán and Guerrero. Tens of millions worth in damage occurred.[83]
During the morning of November 1, a low pressure system formed over the southwestern Caribbean Sea, just north of Panama.[84] The wave crossed Costa Rica and emerged into the eastern Pacific on November 3.[85] Convection swiftly organized as the system gradually became better defined that day, and the disturbance developed into Tropical Depression Eighteen-E at 15:00 UTC on November 4.[86][87] However, dry air (some of which came from a Gulf of Tehuantepec gap wind event) entrained into the storm, keeping it weak and disorganized.[88] The system remained disorganized while moving westward for the next few days, before organizing into Tropical Storm Terry at 21:00UTC on November 7.[89] However, Terry weakened to a tropical depression at 15:00UTC on November 8 as it became less organized.[90] Terry's circulation became better defined later that day, though its convection remained poorly organized. At 06:00 UTC on November 10, the depression opened up into a trough of low pressure.[91]
Terry briefly affected Costa Rica and damaged around 11 houses and knocking over few trees. No fatalities were reported in Costa Rica but Terry's low form brought damage to Panama as well, injuring 1 person.[92] One yellow alert was issued in Mexico though there was no damage there.[93] As a depression, a green alert was issued in the Revillagigedo Islands though it was discontinued a few hours later.[94]
At 19:00 UTC on November 1, the NHC began monitoring a disturbance that was expected to develop into an area of low pressure several miles south of the southwestern coast of Mexico.[95] The system organized further by 01:00 UTC on November 3,[96] and further development prompted the NHC to begin issuing advisories on Tropical Depression Nineteen-E at 15:00 UTC on November 7.[97][98] At 21:00UTC on November7, the depression was upgraded into a tropical storm based on scatterometer data, despite the storm's appearance degrading, and the NHC assigned the storm the name Sandra.[99] However, Sandra weakened into a tropical depression 24 hours later, after scatterometer data failed to find tropical storm-force winds.[100] At 21:00 UTC on November 9, Sandra degenerated into a remnant low, after the storm's surface circulation was found to have opened up into a trough of low pressure.[101]
Other system
The precursor to Tropical Storm Omais would develop in the Central Pacific Ocean, being first noted by the Central Pacific Hurricane Center on August 6. The storm would later cross into the Western Pacific, in which it would no longer be tracked.[102]
The following list of names was used for named storms that formed in the North Pacific Ocean east of 140°W during 2021.[103] This is the same list used in the 2015 season, with the exception of the name Pamela, which replaced Patricia.[104] The name Pamela was used for the first time this year. No names were retired following the season, so this list will be used again for the 2027 season.
For named storms that form in the Central Pacific Hurricane Center's area of responsibility, encompassing the North Pacific between 140°W and the International Date Line, the names come from a series of four rotating lists. Names are used one after the other without regard to year, and when the bottom of one list is reached, the next named storm receives the name at the top of the next list.[103] No storms formed within the area in 2021. Named storms in the table above that crossed into the area during the season are noted (*).[105]
Season effects
This is a table of all of the storms that formed in the 2021 Pacific hurricane season. It includes their name, duration, peak classification and intensities, areas affected, damage, and death totals. Deaths in parentheses are additional and indirect (an example of an indirect death would be a traffic accident), but were still related to that storm. Damage and deaths include totals while the storm was extratropical, a wave, or a low, and all of the damage figures are in 2021 USD.
↑ Hurricanes reaching Category3 (1-minute sustained winds higher than 110 miles per hour (178km/h)) on Saffir–Simpson scale are described as major hurricanes,[1]
↑ The National Hurricane Center 1991-2020 seasonal averages for a Pacific hurricane season are 15 named storms, 8 hurricanes, and 4 major hurricanes.[2]
↑ All damage totals are valued as of 2021 and in United States dollars, unless otherwise noted.
↑ The total represents the sum of the squares of the maximum sustained wind speed (knots) for every (sub)tropical storm's intensity of over 33knots (38mph, 61km/h), divided by 10,000 while they are above that threshold; therefore, tropical depressions are not included.
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The 2011 Pacific hurricane season was a below average season in terms of named storms, although it had an above average number of hurricanes and major hurricanes. During the season, 13 tropical depressions formed along with 11 tropical storms, 10 hurricanes and 6 major hurricanes. The season officially began 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. The season's first cyclone, Hurricane Adrian formed on June 7, and the last, Hurricane Kenneth, dissipated on November 25.
The 2012 Pacific hurricane season was a moderately active Pacific hurricane season that saw an unusually high number of tropical cyclones pass west of the Baja California Peninsula. The season officially began on May 15 in the eastern Pacific Ocean, and on June 1 in the central Pacific (from 140°W to the International Date Line, north of the equator; they both ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in these regions of the Pacific Ocean. However, the formation of tropical cyclones is possible at any time of the year. This season's first system, Tropical Storm Aletta, formed on May 14, and the last, Tropical Storm Rosa, dissipated on November 3.
The 2015 Pacific hurricane season is the second-most active Pacific hurricane season on record, with 26 named storms, only behind the 1992 season. A record-tying 16 of those storms became hurricanes, and a record 11 storms further intensified into major hurricanes throughout the season. The Central Pacific, the portion of the Northeast Pacific Ocean between the International Date Line and the 140th meridian west, had its most active year on record, with 16 tropical cyclones forming in or entering the basin. Moreover, the season was the third-most active season in terms of accumulated cyclone energy, amassing a total of 290 units. The season officially started on May 15 in the Eastern Pacific 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 Northeast Pacific basin. However, the formation of tropical cyclones is possible at any time of the year. This was shown when a tropical depression formed on December 31. The above-average activity during the season was attributed in part to the very strong 2014–2016 El Niño event.
The 2016 Pacific hurricane season was tied as the fifth-most active Pacific hurricane season on record, alongside the 2014 season. Throughout the course of the year, a total of 22 named storms, 13 hurricanes and six major hurricanes were observed within the basin. Although the season was very active, it was considerably less active than the previous season, with large gaps of inactivity at the beginning and towards the end of the season. It officially started on May 15 in the Eastern Pacific, 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 these regions of the Pacific Ocean. However, tropical development is possible at any time of the year, as demonstrated by the formation of Hurricane Pali on January 7, the earliest Central Pacific tropical cyclone on record. After Pali, however, no tropical cyclones developed in either region until a short-lived depression on June 6. Also, there were no additional named storms until July 2, when Tropical Storm Agatha formed, becoming the latest first-named Eastern Pacific tropical storm since Tropical Storm Ava in 1969.
The 2017 Pacific hurricane season was an above average Pacific hurricane season in terms of named storms, though less active than the previous three, featuring eighteen named storms, nine hurricanes, and four major hurricanes. Despite the considerable amount of activity, most of the storms were weak and short-lived. The season officially started on May 15 in the eastern 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 respective regions. However, the formation of tropical cyclones is possible at any time of the year, as illustrated in 2017 by the formation of the season's first named storm, Tropical Storm Adrian, on May 9. At the time, this was the earliest formation of a tropical storm on record in the eastern Pacific basin proper. The season saw near-average activity in terms of accumulated cyclone energy (ACE), in stark contrast to the extremely active seasons in 2014, 2015, and 2016; and for the first time since 2012, no tropical cyclones formed in the Central Pacific basin. However, for the third year in a row, the season featured above-average activity in July, with the ACE value being the fifth highest for the month. Damage across the basin reached $375.28 million (2017 USD), while 45 people were killed by the various storms.
The 2019 Pacific hurricane season was an above average season which produced nineteen named storms, most of which were rather weak and short-lived. Only seven hurricanes formed, the fewest since 2010. The season officially began 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. This season was one of the latest-starting Pacific hurricane seasons on record, with the first tropical cyclone, Hurricane Alvin, forming on June 25. The final system, Tropical Depression Twenty-One-E, dissipated on November 18.
The 2020 Pacific hurricane season was a near average Pacific hurricane season in terms of named storms, featuring 17, but well below average season for hurricanes and major hurricanes, with only 4 hurricanes and 3 major hurricanes forming. Additionally, no tropical cyclones formed in the Central Pacific basin for the first time since 2017. The season officially began on May 15 in the East Pacific Ocean, and on June 1 in the Central Pacific (from 140°W to the International Date Line, north of the equator; they both ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the respective regions. However, the formation of tropical cyclones is possible at any time of the year, as illustrated in 2020 by the formation of the season's first system, Tropical Depression One-E, on April 25. This was the earliest formation of a tropical cyclone on record in the eastern Pacific basin proper. The final system of the season was Tropical Storm Polo, which dissipated on November 19.
The 2022 Pacific hurricane season was a slightly above average hurricane season in the eastern North Pacific basin, with nineteen named storms, ten hurricanes, and four major hurricanes. Two of the storms crossed into the basin from the Atlantic. In the central North Pacific basin, no tropical cyclones formed. The season officially began on May 15 in the eastern Pacific, and on June 1 in the central; both ended on November 30. These dates historically describe the period each year when most tropical cyclogenesis occurs in these regions of the Pacific and are adopted by convention.
Hurricane Dolores was a powerful and moderately damaging tropical cyclone whose remnants brought record-breaking heavy rains and strong winds to California. The seventh named storm, fourth hurricane, and third major hurricane of the record-breaking 2015 Pacific hurricane season, Dolores formed from a tropical wave on July 11. The system gradually strengthened, attaining hurricane status on July 13. Dolores rapidly intensified as it neared the Baja California peninsula, finally peaking as a Category 4 hurricane on the Saffir–Simpson scale with winds of 130 mph (215 km/h) on July 15. An eyewall replacement cycle began and cooler sea-surface temperatures rapidly weakened the hurricane, and Dolores weakened to a tropical storm two days later. On July 18, Dolores degenerated into a remnant low west of the Baja California peninsula.
Hurricane Douglas was a strong tropical cyclone that became the closest passing Pacific hurricane to the island of Oahu on record, surpassing the previous record held by Hurricane Dot in 1959. The eighth tropical cyclone, fifth named storm, first hurricane, and first major hurricane of the 2020 Pacific hurricane season, Douglas originated from a tropical wave which entered the basin in mid-July. Located in favorable conditions, the wave began to organize on July 19. It became a tropical depression on July 20 and a tropical storm the following day. After leveling off as a strong tropical storm due to dry air, Douglas began rapid intensification on July 23, becoming the season's first major hurricane the following day and peaking as a Category 4 hurricane. After moving into the Central Pacific basin, Douglas slowly weakened as it approached Hawaii. The storm later passed north of the main islands as a Category 1 hurricane, passing dangerously close to Oahu and Kauai, causing minimal damage, and resulting in no deaths or injuries. Douglas weakened to tropical storm status on July 28, as it moved away from Hawaii, before degenerating into a remnant low on July 29 and dissipating on the next day.
Hurricane Genevieve was a strong tropical cyclone that almost made landfall on the Baja California Peninsula in August 2020. Genevieve was the twelfth tropical cyclone, seventh named storm, third hurricane, and second major hurricane of the 2020 Pacific hurricane season. The cyclone formed from a tropical wave that the National Hurricane Center (NHC) first started monitoring on August 10. The wave merged with a trough of low pressure on August 13, and favorable conditions allowed the wave to intensify into Tropical Depression Twelve-E at 15:00 UTC. Just six hours later, the depression became a tropical storm and was given the name Genevieve. Genevieve quickly became a hurricane by August 17, and Genevieve began explosive intensification the next day. By 12:00 UTC on August 18, Genevieve reached its peak intensity as a Category 4 hurricane, with maximum 1-minute sustained winds of 130 mph and a minimum central pressure of 950 millibars (28 inHg). Genevieve began to weaken on the next day, possibly due to cooler waters caused by Hurricane Elida earlier that month. Genevieve weakened below tropical storm status around 18:00 UTC on August 20, as it passed close to Baja California Sur. Soon afterward, Genevieve began to lose its deep convection and became a post-tropical cyclone by 21:00 UTC on August 21, eventually dissipating off the coast of Southern California late on August 24.
Hurricane Marco was the first of two tropical cyclones to threaten the Gulf Coast of the United States within a three-day period. The thirteenth named storm and third hurricane of the record-breaking 2020 Atlantic hurricane season, Marco developed from a fast-moving tropical wave west of the Windward Islands and south of Jamaica on August 20. The fast motion of the wave inhibited intensification initially, but as the wave slowed down and entered a more favorable environment, the system developed into a tropical depression, which in turn rapidly intensified into a strong tropical storm. Due to strong wind shear, Marco's intensification temporarily halted. However, after entering the warm waters of the Gulf of Mexico on August 23, Marco briefly intensified into a hurricane, only to quickly weaken later that evening due to another rapid increase in wind shear. Marco subsequently weakened to a tropical depression before degenerating into a remnant low early the next morning. Marco's remnants subsequently dissipated on August 26.
Hurricane Laura tied the record for the strongest hurricane to make landfall in Louisiana as measured by maximum sustained winds, along with the 1856 Last Island hurricane and Hurricane Ida, and was overall the tenth-strongest hurricane to make landfall in the United States. The thirteenth tropical cyclone, twelfth named storm, fourth hurricane, and first major hurricane of the 2020 Atlantic hurricane season, Laura originated from a large tropical wave that moved off the West African coast on August 16. The tropical wave gradually organized, becoming a tropical depression on August 20. Though in only a marginally conducive environment for intensification, the depression nevertheless intensified into a tropical storm a day later, becoming the earliest twelfth named storm on record in the North Atlantic basin, forming eight days earlier than 1995's Hurricane Luis. The depression received the name Laura and tracked west-northwest towards the Lesser Antilles.
Hurricane Gamma was a tropical cyclone that brought heavy rains, flooding, and landslides to the Yucatán Peninsula in early October 2020. The twenty-fifth depression, twenty-fourth named storm and ninth hurricane of the extremely active 2020 Atlantic hurricane season, Gamma developed from a vigorous tropical wave that had been monitored as it was entering the Eastern Caribbean on September 29. The wave moved westward and slowed down as it moved into the Western Caribbean, where it began to interact with a dissipating cold front. A low formed within the disturbance on October 1 and the next day, it organized into a tropical depression. It further organized into Tropical Storm Gamma early the next day. It continued to intensify and made landfall as a minimal hurricane near Tulum, Mexico, on October 3. It weakened over land before reemerging in the Gulf of Mexico. Gamma then briefly restrengthened some before being blasted by high amounts of wind shear, causing it to weaken again. It made a second landfall as a tropical depression in Nichili, Mexico on October 6 before dissipating as it was absorbed by the approaching Hurricane Delta.
The 2023 Pacific hurricane season was an active and destructive Pacific hurricane season. In the Eastern Pacific basin, 17 named storms formed; 10 of those became hurricanes, of which 8 strengthened into major hurricanes – double the seasonal average. In the Central Pacific basin, no tropical cyclones formed for the fourth consecutive season, though four entered into the basin from the east. Collectively, the season had an above-normal accumulated cyclone energy (ACE) value of approximately 168 units. This season saw the return of El Niño and its associated warmer sea surface temperatures in the basin, which fueled the rapid intensification of several powerful storms. It officially began on May 15, 2023 in the Eastern Pacific, and on June 1 in the Central; both ended on November 30. These dates, adopted by convention, historically describe the period in each year when most tropical cyclogenesis occurs in these regions of the Pacific.
The 2024 Pacific hurricane season is the ongoing Pacific hurricane season in the Northern Hemisphere. It officially began on May 15 in the eastern Pacific basin and on June 1 in the central Pacific ; both will end on November 30. These dates, adopted by convention, historically describe the period in each year when most subtropical or tropical cyclogenesis occurs in these regions of the Pacific Ocean. For the third consecutive year, there were no pre-season tropical cyclones in either basin, and the season got off to the slowest start of any Pacific hurricane season on record in the satellite era. The first eastern Pacific tropical storm, Aletta, did not form until July 4. The first central Pacific tropical storm, Hone, formed on August 22, becoming the first named storm to develop in the basin since 2019.
The 2021 Pacific hurricane season was a moderately active hurricane season, with above-average tropical activity in terms of named storms, but featured below-average activity in terms of major hurricanes. It is the first season to have at least five systems make landfall in Mexico, the most since 2018. It was also the second consecutive season in which no tropical cyclones formed in the Central Pacific. The season officially began on May 15 in the Eastern Pacific, and on June 1 in the Central Pacific; both ended on November 30. These dates historically describe the period each year when most tropical cyclones form in the eastern and central Pacific and are adopted by convention. However, the formation of tropical cyclones is possible at any time of the year, as illustrated this year by the formation of Tropical Storm Andres on May 9. This was the earliest forming tropical storm on record in the Eastern Pacific. The season effectively ended with the dissipation of Tropical Storm Terry, on November 10.
Hurricane Enrique was a Category 1 Pacific hurricane that brought heavy rainfall and flooding to much of western Mexico in late June 2021. The fifth named storm and first hurricane of the 2021 Pacific hurricane season, Enrique developed from a tropical wave the entered the Pacific Ocean off the coast of Nicaragua on June 22. In an environment conducive for intensification, the disturbance moved west-northwestward and developed into a tropical storm by 6:00 UTC on June 25, as it was already producing winds of 40 mph (65 km/h), and received the name Enrique. Enrique strengthened steadily within an environment of warm waters and low-to-moderate wind shear while continuing its northwestward motion. By 12:00 UTC on June 26, Enrique had intensified into a Category 1 hurricane as the storm turned more northwestward. Nearing the coast of Mexico, Enrique reached its peak intensity around 6:00 UTC the following day, with maximum sustained winds of 90 mph (150 km/h) and a minimum barometric pressure of 972 mbar (28.7 inHg). Enrique, passing closely offshore west-central Mexico, maintained its intensity for another 24 hours as it turned northward toward the Gulf of California. Turning back to the northwest on June 28, increasing wind shear and dry air caused the hurricane to weaken. Enrique dropped to tropical storm status at 18:00 UTC that day, and further weakened to a tropical depression on June 30 just to the northeast of Baja California. The depression was absorbed into a larger low pressure area to the southeast later that day.
↑ Neal Dorst. When is hurricane season? (Report). Atlantic Oceanographic and Meteorological Laboratory. Archived from the original on December 6, 2010. Retrieved November 25, 2010.
↑ Philippe P. Papin; John L. Beven II (July 16, 2021). "Hurricane Felicia Discussion Number 13". Miami, Florida: National Hurricane Center. Retrieved December 25, 2021.
↑ John L. Beven II; Christopher W. Landsea (November 5, 2021). Tropical Cyclone Report: Tropical Storm Ignacio(PDF) (Report). Miami, Florida: National Hurricane Center. Retrieved December 25, 2021.
1 2 National Hurricane Operations Plan(PDF) (Report). Washington, D.C.: NOAA Office of the Federal Coordinator for Meteorological Services and Supporting Research. May 2021. pp.3-10–12. Retrieved March 7, 2024.
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