2001 Pacific hurricane season

Systems

Hurricane Adolph

On May 7, a tropical wave exited the west coast of Africa and moved across the Atlantic. A weak low pressure area began forming along the wave axis on May 18. The system crossed into the eastern Pacific on May 22. At first the system was disorganized, until convection, or thunderstorms, became more organized on May 24. On the next day, it developed into Tropical Depression One-E about 250 miles (400 km) south-southwest of Acapulco, Mexico. The nascent depression moved slowly eastward, steered by a ridge to the north. With low wind shear and warm water temperatures, the depression strengthened into Tropical Storm Adolph on May 26. A day later, the storm had developed an eye, as the storm turned northwestward. Late on May 27, Adolph attained hurricane status, and the next day it passed about 165 mi (265 km) southwest of Acapulco. Continuing to strengthen, Adolph reached peak winds of 145 mph (230 km/h) on May 29, making it a Category 4 hurricane. While it was rapidly intensifying, Adolph's pressure dropped 1.46 mbars per hour, falling to a minimum of 940 mbar (28 inHg). The hurricane underwent an eyewall replacement cycle and it subsequently weakened. Water and air temperatures cooled, and Adolph fell to tropical storm status on June 1 as the convection rapidly diminished. It quickly weakened into a tropical depression, and was no longer a tropical cyclone by June 2. The remaining clouds persisted for a few more days to the southwest of the Baja California peninsula.

Due to Adolph's threat, the government of Mexico issued a tropical storm warning and a hurricane watch from Acapulco to Lázaro Cárdenas. Ports in Acapulco were closed to small vessels. Adolph ultimately produced rainfall and heavy surf to the southwest Mexican coastline.

Tropical Storm Barbara

A tropical wave moved off the coast of Africa on June 1, which entered the eastern Pacific ten days later. Continuing to the west, the wave eventually developed a broad circulation on June 18. After further organization, the system developed into Tropical Depression Two-E on June 20, located about 1,325 mi (2,130 km) southwest of Cabo San Lucas, Mexico. Within 18 hours of forming, the depression strengthened into Tropical Storm Barbara. On June 21, Barbara attained peak winds of 60 mph (95 km/h). Around that time, the convection had become more organized, with banding features. Shortly thereafter, the storm encountered stronger wind shear and cooler water temperatures. On June 22, Barbara weakened into a tropical depression as it crossed into the central Pacific. It was the recorded first June tropical cyclone in the central Pacific. On June 23, the CPHC issued its final advisory on Barbara. The circulation continued to the west-northwest, passing north of the Hawaiian Islands on June 25. Across the state, the storm brought 5 to 8 ft (1.5 to 2.4 m) waves, along with unsettled weather. The circulation dissipated northwest of Kauai on June 26, and the remnants were absorbed by a frontal zone near Midway Island.

Tropical Storm Cosme

A tropical wave entered the eastern Pacific basin on July 6, and proceeded westward. A low pressure area formed on July 10, but it was halted by wind shear from an upper-level trough. The system gradually organized, developing into Tropical Depression Three-E on July 13, located about 330 mi (530 km) southwest of Manzanillo, Mexico. It quickly strengthened into Tropical Storm Cosme, and within 12 hours of forming, it attained peak winds of 45 mph (75 km/h). On July 14, the wind shear stripped the thunderstorms from the center, causing Cosme to weaken back into a tropical depression. Moving over cooler waters, Cosme degenerated into a remnant low on July 15, although the circulation lasted another three days before dissipating.

Tropical Storm Erick

A tropical wave reached the eastern Pacific on July 16. Continuing westward, it developed an area of thunderstorms on July 18 while the system was south of the Baja California peninsula. Following gradual organization, Tropical Depression Four-E developed late on July 20, located about 790 mi (1,275 km) southwest of the southern tip of the Baja California peninsula. The depression moved to the west-northwest, although it was large and disorganized, impacted by wind shear. Late on July 21, the depression intensified into Tropical Storm Erick, reaching peak winds of 40 mph (65 km/h) and a minimum pressure of 1,001 mbar (29.6 inHg). Erick soon encountered cooler waters, which prevented further strengthening. The storm fell to tropical depression status on July 23, and degenerated into a remnant low the next day, which produced intermittent thunderstorms before dissipating.

Hurricane Dalila

A tropical wave entered the eastern Pacific on July 18. Continuing westward, the system gradually organized. Early on July 21, it developed into Tropical Depression Five-E, located about 250 mi (400 km) south of the Gulf of Tehuantepec. A subtropical ridge the north steered the system to the west-northwest, parallel to the southern Mexican coastline. Within 12 hours of forming, the depression strengthened into Tropical Storm Dalila, aided by warm water temperatures and low wind shear. On July 22, the storm approached within 115 mi (185 km) of the southwest Mexican coast, between Acapulco and Manzanillo. Moving farther offshore, Dalila briefly reached hurricane status on July 24, with peak winds of 75 mph (120 km/h) and a minimum pressure of 987 mbar (987 hPa). The NHC assessed the estimated peak intensity based on the circulation embedded within the central dense overcast, and a warm spot in the center. Soon after peaking, Dalila began weakening due to increased wind shear. It passed directly over Socorro Island on July 25 as a tropical storm. Although the wind shear dropped, the water temperatures cooled, causing the thunderstorms to diminish. On July 28, Dalila fell to tropical depression status, and it dissipated soon after off the southwest coast of the Baja California peninsula.

The threat of the Dalila led to tropical storm warnings in southwestern Mexico from Punta Maldonado, Guerrero to Lázaro Cárdenas, Michoacán. This included a hurricane watch from Lázaro Cárdenas to Manzanillo. The storm produced heavy rainfall in southwest Mexico that led to flash flooding. In Chiapas, lightning strikes killed two people and injured eight others. Dozens of homes were damaged by the floods in the state, affecting about 1,000 people. In Guererro, rainfall reached 6.3 in (161 mm). In Acapulco, the floods damaged about 20 homes.

Hurricane Flossie

The origins of Flossie were from the same tropical wave that spawned Tropical Storm Chantal in the Atlantic. The southern portion of the wave crossed into the eastern Pacific on August 21, and continued westward without much organization at first. On August 25, the system passed near Manzanillo, producing wind gusts of 46 mph (74 km/h) there. The circulation was too broad for the system to be classifiable as a tropical cyclone at the time. As it moved away from the Mexican coast, the circulation became better defined. On August 26, the system developed into Tropical Depression Seven-E while located about 270 mi (435 km) southeast of the southern tip of the Baja California peninsula. It quickly strengthened into Tropical Storm Flossie. Steered by a ridge to its north, Flossie moved to the west-northwest, passing just north of Socorro Island. Late on August 27, Flossie attained hurricane status, despite wind shear from a nearby upper-level low. The two systems interacted, causing Flossie to slow, turn to the southwest, and execute a small loop. After the upper-level low moved northeastward away from the hurricane, Flossie strengthened further, as the eye became better defined. On August 29, the hurricane reached peak winds of 105 mph (165 km/h), and a minimum pressure of 972 mbar (28.7 inHg). Soon after, Flossie weakened due to wind shear from an approaching mid-level trough. It fell to tropical storm status on August 31 as water temperatures decreased. Flossie weakened further into a tropical depression on September 1 while curving to the northeast. It dissipated on September 2, although the circulation persisted for a few more days.

While Flossie was dissipating, its middle and upper-level circulation moved across Baja California and into the southwestern United States. The remnants of the storm generated thunderstorms across southern California, killing two people due to lightning strikes. The lightning injured two other people and also led to several small fires. The thunderstorms also produced flash flooding in San Diego and Riverside counties in California after dropping more than 2 in (51 mm) of rain in one hour. The floods caused mudslides that affected several roads. A strong downdraft knocked a tree onto a house. Damage in California reached $35,000.

Hurricane Gil

The same tropical wave that spawned Atlantic Tropical Storm Dean also entered the eastern Pacific on August 24. Continuing westward into a monsoon-like environment, the system slowly organized, developing into a tropical depression on September 4. At the time, it was located about 850 mi (1,370 km) southwest of the southern tip of the Baja California peninsula. The depression quickly intensified into Tropical Storm Gil. Developing a ragged eye, Gil attained hurricane status on September 6, and later that day reached peak winds of 100 mph (155 km/h), with a minimum pressure of 975 mbar (28.8 inHg). Around the time of Gil reaching peak intensity, it interacted with nearby Tropical Storm Henriette, and the two storms orbited around each other. Outflow from Henriette caused Gil to weaken as the hurricane accelerated northward, and Gil weakened to tropical storm status on September 8. On the next day, the track shifted to the southwest as Gil absorbed the remnants of Henriette and it fell to tropical depression status. Gil was no longer a tropical cyclone by September 10, although the circulation continued to the northwest over the next few days. On September 19, a cold front north of Hawaii absorbed the remnants of Gil.

Tropical Storm Henriette

A tropical wave crossed Central America into the eastern Pacific by August 29. Moving westward to the south of Mexico, the system's thunderstorms gradually organized. On September 4, Tropical Depression Nine-E developed about 345 mi (555 km) west-southwest of Manzanillo. At the time of its formation, the depression was located about 880 mi (1,415 km) east of Tropical Storm Gil. On September 5, the depression intensified into Tropical Storm Henriette, which continued to organize, developing outflow and rainbands. On September 7, Henriette reached peak winds of 65 mph (100 km/h), with a minimum pressure of 994 mbar (29.4 inHg). Afterward, the storm moved over cooler waters, while also revolving around the northern periphery of Gil. Losing thunderstorms, Henriette weakened to a tropical depression on September 8, and soon after was no longer classifiable as a tropical cyclone. The dissipating circulation was absorbed by Gil on September 9.

Tropical Storm Ivo

A tropical wave exited western Africa on August 26, and continued across the Atlantic and into the eastern Pacific. The circulation began organizing near the southern Mexican coast on September 9. Moving offshore, it developed into Tropical Depression Ten-E on September 10, while located about 115 mi (185 km) southwest of Acapulco. The depression continued to the west-northwest, just offshore the southwest Mexican coast. On September 11, it strengthened into Tropical Storm Ivo, although it was affected by wind shear. A day later, Ivo reached peak winds of 50 mph (85 km/h), while the circulation was on the northern edge of the convection. Around that time, Ivo was located south of the Baja California peninsula, moving into an area of cooler waters. The storm weakened into a tropical depression on September 14, and degenerated into a remnant low early the next day.

Due to its passage near Mexico's southwest coast, the country's government issued tropical storm warnings from Acapulco to Cabo Corrientes, and for the southern Baja California peninsula from Cabo San Lucas to Cabo San Lazaro. Ivo's outer rainbands affected Guerrero, Michoacán, Colima, Jalisco, and Baja California Sur.

Hurricane Juliette

A tropical wave exited western Africa on September 11, which crossed the Atlantic and Caribbean Sea. On September 19, it developed into Atlantic Tropical Depression Nine, which quickly dissipated while crossing Central America. After reaching the eastern Pacific, the remnants redeveloped into a tropical depression on September 21, located about 165 km (105 mi) south of Guatemala. It strengthened into Tropical Storm Juliette and continued to intensify, as it paralleled Mexico's Pacific coast. On September 23, Juliette became a hurricane, and it rapidly intensified into a Category 4 hurricane. The hurricane underwent an eyewall replacement cycle and briefly weakened before re-intensifying. On September 25, Juliette attained peak winds of 145 mph (230 km/h), with a minimum pressure of 923 mbar (27.3 inHg). Cooler waters and stronger wind shear caused it to weaken again. On September 28, Juliette passed just west of Cabo San Lucas as a minimal hurricane, before making landfall near San Carlos as a minimal tropical storm two days later. Juliette crossed the Baja California Peninsula into Gulf of California as a tropical depression and dissipated over the far northern part of the gulf on October 3.

During its path across the Pacific, Juliette affected much of the Pacific coast of Mexico, killing 13 people from Chiapas to the Baja California peninsula. The strongest winds and heaviest rainfall occurred in Baja California Sur, with wind gusts of 174 km/h (108 mph), and a precipitation total of 1,011 mm (39.80 in) recorded at Santiago. Damage in the country was estimated at over US$400 million, of which the worst effects were in the state of Sonora. There, the rains over three days equaled the average annual precipitation, which resulted in flooding and landslides. Thunderstorms extended into the southwestern United States, knocking down power lines near Palm Springs.

Hurricane Kiko

The same tropical wave that produced Atlantic Hurricane Felix later entered the eastern Pacific by September 16. Convection increased as it moved westward, eventually becoming more consolidated. On September 21, the system organized into Tropical Depression Twelve-E, located about 635 mi (1,020 km) southwest of the southern tip of Baja California. Due to easterly wind shear, the system slowly organized, strengthening into Tropical Storm Kay on September 22. Deep convection persisted near the center, and an eye feature developed. On September 23, Kay briefly attained hurricane status, with peak winds of 75 mph (120 km/h) and an estimated minimum pressure of 990 mbar (29 inHg). Soon after peaking in intensity, Kay weakened due to stable air as the thunderstorms dwindled. On September 25, the storm fell to tropical depression status and quickly degenerated into a remnant low. The circulation continued westward for the next few days until it was absorbed by a frontal system northeast of Hawaii on October 1.

Tropical Storm Lorena

A tropical wave exited western Africa on September 13, and crossed Central America two weeks later. Continuing to the west, the thunderstorms and gradually organized. On October 2, Tropical Depression 13-E formed about 370 mi (600 km) south-southwest of Acapulco, Mexico. Within 12 hours of developing, the depression strengthened into Tropical Storm Lorena as it moved to the northwest. On October 3, Lorena attained peak winds of 60 mph (95 km/h), and a minimum pressure of 997 mbar (29.4 inHg). Soon after, the convection began to weaken due to wind shear. The storm fell to tropical depression status on October 4, as the track shifted to the north. By October 5, Lorena was no longer classifiable as a tropical cyclone, and the circulation dissipated just west of Cabo Corrientes, Jalisco.

The storm led to a tropical storm warning and a hurricane watch, from Punta San Telmo northward to Mazatlán. Lorena's outer rainbands affected Jalisco and Nayarit.

Tropical Storm Manuel

On October 4, a tropical wave spawned a tropical depression in the Atlantic, which became Hurricane Iris. The hurricane struck Belize on October 9 and quickly dissipated over eastern Mexico. While Iris was dissipating, new convection was developing along Mexico's Pacific coast. The system continued westward and became Tropical Depression Fifteen-E on October 10, located about 200 mi (325 km) south-southeast of Acapulco. A day later, it strengthened into Tropical Storm Manuel, although it was soon disrupted by wind shear. On October 12, Manuel weakened to a tropical depression. The track shifted to the west-southwest as a ridge weakened to its north, until an upper-level trough turned the depression to the northwest. Manuel regained tropical storm strength on October 15, as convection increased. On the next day, the storm reached peak winds of 60 mph (95 km/h), with a minimum pressure of 997 mbar (29.4 inHg). Cooler waters and a return of wind shear caused the storm to weaken again. On October 17, Manuel weakened to a tropical depression, and it degenerated into a remnant low the next day. The circulation continued slowly westward for a few days until dissipating.

Manuel's outer rainbands affected coastal areas of southwest Mexico from Guerrero to Nayarit.

Hurricane Narda

A tropical wave exited Africa on October 3, and crossed Central America 12 days later. After reaching the eastern Pacific, the wave continued westward, developing banding features and several circulations. The system consolidated into Tropical Depression Sixteen-E on October 20, located about 1,320 mi (2,130 km) southwest of the southern tip of the Baja California peninsula. With warm waters, the depression quickly intensified into Tropical Storm Narda as it moved to the west-northwest. It developed outflow and deep thunderstorms, and after a ragged eye formed, Narda attained hurricane status late on October 21. On the next day, it reached peak winds of 85 mph (140 km/h) and a minimum pressure of 980 mbar (29 inHg). Narda remained a hurricane until October 23, when it weakened due to wind shear. Later that day, the storm crossed into the Central Pacific as it deteriorated further to a tropical depression. The circulation dissipated on October 25, about 575 mi (925 km) east-southeast of the island of Hawaii.

Hurricane Octave

The final storm of the season originated from an area of thunderstorms within the Intertropical Convergence Zone (ITCZ) that increased on October 27. Its origins were likely related to a tropical wave that crossed Central America five days prior. The system moved westward, developing into a tropical depression on October 31, located about 1,180 mi (1,900 km) southwest of the southern tip of Baja California. Moving to the northwest, it quickly strengthened into Tropical Storm Octave, amid low wind shear. A ragged eye developed on November 1, and that day, Octave attained hurricane status. On November 2, the hurricane reached peak winds of 85 mph (140 km/h) and a minimum barometric pressure of 980 mbar (29 inHg). Soon after, increased wind shear weakened Octave, while sea surface temperatures were decreasing, causing the circulation to become displaced from the deep convection. On November 3, Octave fell to tropical depression status as the thunderstorms dwindled and the circulation started dissipating.

Tropical depressions

A tropical wave entered the Pacific by August 13, and continued westward. It began to become better organized on August 21. A day later, it developed into Tropical Depression Six-E about 1,300 mi (2,090 km) southeast of Hawaii. The depression attained peak winds of 35 mph (55 km/h), before being affected by cooler waters and stronger wind shear. Early on August 24, the circulation dissipated.

On September 11, Tropical Depression One-C developed about 415 mi (665 km) southeast of the island of Hawaii. The depression attained peak winds of 35 mph (55 km/h), although it never became well-organized, and the track was erratic. It dissipated about 12 hours after forming.

Tropical Depression Two-C formed on September 22, located southwest of Tropical Storm Kiko, and about 820 mi (1,320 km) southeast of the island of Hawaii. Upon its formation, the depression had peak winds of 35 mph (55 km/h). As it moved westward, strong wind shear prevented strengthening, and the depression dissipated on September 25 to the southwest of Hawaii.

The final undeveloped depression originated from the Intertropical Convergence Zone. Moving westward, its thunderstorms became better organized, developing into Tropical Depression Fourteen-E on October 3. At the time, it was located about 920 mi (1,480 km) southwest of the southern tip of the Baja California peninsula. Affected by wind shear and dry air, the depression dissipated on October 4.

Storm names

The following list of names was used for named storms that formed in the North Pacific east of 140°W during 2001. This is the same list used for the 1995 season except for Ivo, which ultimately replaced Ismael. The season's naming list originally had the name Israel replace Ismael, before being changed during the season. A storm was named Ivo for the first time in 2001.

No named storms formed in the central North Pacific in 2001. Named storms that crossed into the area during the year are noted (*).

Retirement

The name Adolph was retired following its usage in 2001, was replaced with Alvin starting with the 2007 season.

Season effects

This is a table of all of the tropical cyclones that formed in the 2001 Pacific hurricane season. It includes their name, duration (within the basin), 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 2001 USD.