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2006 Pacific hurricane season
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The 2006 Pacific hurricane season was an event in the annual cycle of tropical cyclone formation. It officially began May 15, 2006 in the eastern Pacific, designated as the area east of 140°W, and began on June 1, 2006 in the central Pacific, which is between the International Date Line and 140°W. Both seasons officially ended on November 30, 2006. These dates conventionally delimit the period of each year when most tropical cyclones form in the eastern Pacific basin.
Seasonal forecasts
Predictions of tropical activity in the 2006 season
for the Eastern North Pacific
| Source |
Date |
Named
storms |
Hurricanes |
Major
hurricanes |
| NOAA |
Average[1] |
15.3 |
8.8 |
4.2 |
| NOAA |
22 May 2006 |
12 – 16 |
6 – 8 |
1 – 3 |
|
Actual activity |
18 |
10 |
5 |
On May 22, 2006, NOAA released their forecasts for the 2006 Atlantic, East Pacific, and Central Pacific hurricane seasons. They predicted a below-normal level of activity in the Eastern Pacific, with 12 to 16 named storms, of which 6 to 8 were expected to become hurricanes, and 1 to 3 expected to become major hurricanes.[2] The Central Pacific basin was also expected to be below average, with only two to three tropical cyclones expected to form or cross into the area.[3] They expected that neither El Niño nor La Niña would affect conditions significantly.[2]
Storms
- See also: Timeline of the 2006 Pacific hurricane season
Tropical Storm Aletta
An area of disturbed weather located south-southwest of the Mexican port of Acapulco, Guerrero, was first detected on May 23, just eight days into the season. It gradually gained organized convection and was classified as a tropical depression early on May 27. It became a tropical storm later that morning, the first of 2006 in the Western Hemisphere. While named tropical cyclones in May are infrequent events, Aletta marked the seventh consecutive year to have a named cyclone form in May.[4]
That same day, Aletta strengthened to a tropical storm with 45 mph (75 km/h) sustained winds, while moving towards the Guerrero coast in southwestern Mexico, which forced the Mexican government to issue tropical storm watches between Punta Maldonado and Zihuatanejo.[5] Aletta then became stationary over the Guerrero and Oaxaca coastlines, but it later turned to the west and weakened on May 29. Aletta continued to weaken until it dissipated on May 30.
Aletta produced moderate rainfall across Mexico, including a 24-hour rainfall total of 100.2 mm (3.94 inches) in Jacatepec, Oaxaca on May 30, and 96.0 mm (3.78 inches) in La Calera, Guerrero, the next day.[5] There were, however, no reports of damage, flooding, or casualties.[4][6]
Tropical Depression Two-E
On June 1, an area of disturbed weather developed near the same area in which Aletta formed. High shear slowed the development of the system. However, it gained enough convection and organization to be classified as a tropical depression on June 3. The depression strengthened to near tropical storm status as it approached the coast of southwestern Mexico; however, shear persisted over the system and it weakened before dissipating on June 4.
Despite never becoming a named storm, heavy rain occurred, with Acapulco receiving between 10-12 inches (250-300 mm) of rain as a result of the depression. Mudslides and flooding occurred in association with 2-E.[7][8]The maximum rainfall estimated to have been produced by Tropical Depression Two-E was 26.0 inches on June 4.[9]
Hurricane Bud
After over a month of inactivity, a disturbance in the Eastern Pacific off the Peninsula of Baja California began to intensify, and it was designated as Tropical Depression Three-E on July 10 local time (July 11 UTC), while about 750 miles (1200 km) south of the tip of Baja California, and began to move away from the Mexican coast. On July 11, just six hours after the first advisory, it strengthened into Tropical Storm Bud. After that, Bud rapidly intensified under favorable conditions. It developed an eye on the afternoon of July 11 and was designated a hurricane in a special advisory in the late afternoon. It continued to intensify and eventually became a major hurricane late on July 12. On July 13, Bud reached a peak of maximum sustained winds of 125 mph (205 km/h)[10] and a minimum pressure of 953 mbar as a strong Category 3 hurricane. It then weakened rapidly as it moved over much colder waters, losing almost all its convection and weakening to a tropical storm on July 14 and later weakening to tropical depression status on July 15. The depression continued losing convection and degenerated into a remnant low later that day, without ever threatening land.[10]
Hurricane Carlotta
Late on July 11, a new tropical depression formed about 250 miles (400 km) southwest of the Mexican state of Guerrero. The depression intensified quickly, and six hours later it was upgraded to tropical storm status, receiving the name Carlotta.[11] The storm continued to strengthen, and became a hurricane 24 hours later.[12] However, the system encountered unfavorable conditions and cooler waters and weakened into a tropical storm during the afternoon of July 14.[13] However, Carlotta managed to regain some convection and restrengthened into a hurricane late that evening, only to weaken back into a tropical storm again the following morning. The system continued to weaken and was downgraded to tropical depression status on the morning of July 16. Carlotta degenerated into a non-convective remnant low later that night.
Hurricane Daniel
- Main article: Hurricane Daniel (2006)
On July 16, a tropical disturbance formed far to the south of the Baja California Peninsula and quickly increased in convective activity and organization. The NHC designated it as a tropical depression that night (July 17 UTC). The depression continued to organize and was designated as a tropical storm the next day. The storm continued to intensify and was declared a hurricane on July 18. Early on July 20, Hurricane Daniel underwent rapid intensification and reached major hurricane status (Category 3) and was later upgraded further to Category 4 status. After several repeated eyewall replacement cycles, Daniel later became an annular hurricane, allowing it to maintain Category 4 status for longer than it otherwise would have.
It crossed over into the Central North Pacific basin early on July 24 and was predicted to affect Hawaii as a tropical storm. However, Daniel encountered weak steering currents in the open ocean, causing it to slow down considerably. It rapidly degenerated to a tropical depression on July 25 and the CPHC issued its last advisory on July 26 while the storm was still well to the east of Hawaii.
Tropical Storm Emilia
- Main article: Tropical Storm Emilia (2006)
A tropical depression formed on July 21 from an area of disturbed weather 380 miles (610 km) south-southwest of Acapulco, and became Tropical Storm Emilia on July 22. Tropical storm watches were issued on the Mexican coast soon afterwards due to uncertainties in its track, but were discontinued after the storm turned northwestwards away from the coast. It later approached the Baja California Peninsula and brought tropical storm-force winds to the southern tip and western coast of the peninsula before it turned northwestwards and rapidly weakened.
Emilia was expected to peak as a Category 1 or 2 hurricane on July 24 or July 25, but due to hostile conditions it did not gain hurricane strength. However, it did reach a peak of 65 mph (100 km/h) and was beginning to form an eyewall when it peaked in intensity.
Tropical Storm Fabio
An area of low pressure tracked westward over the open Pacific in the last week of July. It gradually developed better organization and became a tropical depression on the afternoon of July 31. It continued to organize and was designated Tropical Storm Fabio six hours later. The storm moved westward over open waters and did not strengthen significantly due to strong wind shear. Fabio weakened into a tropical depression on August 2 and degenerated into a remnant low on August 3.
Tropical Storm Gilma
Tropical Depression Eight-E formed off the coast of Central America late on July 31, and slowly strengthened into a tropical storm by August 1. It encountered shearing winds and dry air, weakened to a depression the next day, and dissipated on August 3.
Hurricane Hector
Hurricane Hector originated from a tropical wave that emerged from the western coast of Africa on July 31.[14] The wave was ill-defined, while traversing the Atlantic Ocean, but became more active as it entered the Caribbean Sea. On August 10, the wave crossed Central America an entered the Eastern Pacific basin. The shower and thunderstorm activity within the wave began to increase, strengthening the wave into a low-pressure system on August 13. Dvorak classifications were initiated on August 15 as the system became more convective. The low-pressure system was designated Tropical Depression Nine-E on August 15.
Tropical Depression Nine-E moved west-northwestward to the south of a mid-level ridge, the depression quickly intensified into Tropical Storm Hector on August 16.[14] Shear was moderate in the area, but was able to strengthen into a hurricane on August 17. As Hector continued west-northwest, it was able to intensify further. Hector reached its peak intensity of 110 mph on August 18 at 600 UTC. Hector maintained Category 2 status for 24 hours, encountering cooler sea temperatures soon after. Along with wind shear, the cooler temperatures caused Hector to weaken. Hector fell below hurricane strength on August 20, as convection became limited to the northeast corner of the storm.
The wind shear was not strong enough to weaken the cyclone totally, as Hector remained a 50 mph (80 km/h) storm for 24 hours.[14] Hector weakened into a tropical depression on August 23 and degenerated into a remnant low six hours later. Hector continued westward, crossing into the Central Pacific, and dissipating on August 24 near the Hawaiian Islands.
Hurricane Ioke
- Main article: Hurricane Ioke
A persistent tropical disturbance embedded in a trough gained convection and developed into a tropical depression about 775 miles south of Honolulu on August 19. It continued to strengthen, and the Central Pacific Hurricane Center upgraded the depression to a tropical storm, just six hours after forming. The Central Pacific Hurricane Center designated the system with the name Ioke (pronounced /iːˈoʊkeɪ/), which is Hawaiian for the name Joyce,[15] becoming the first tropical storm to form in the Central Pacific since 2002. After undergoing rapid development, Ioke strengthened into a hurricane just 24 hours after it had formed; it continued to rapidly intensify and became a major hurricane (Category 3 or greater) on the morning of August 21. Later that day, Ioke intensified even further into a Category 4 hurricane. On August 22, it began to weaken, and was downgraded back to a Category 2. The National Weather Service reported that the eastern eyewall of Ioke passed over the uninhabited Johnston Atoll,[16] buffeting it with hurricane-force winds. The storm began to deepen again late on August 23 as it moved over increasingly warm water, reaching major hurricane status for the second time while moving to the west-northwest.
Twelve people on a United States Air Force vessel in the Pacific were forced to abandon ship and take shelter in a hurricane-proof bunker on the island.[17] They were reported safe the next day, and a reconnaissance flight reported little damage on the island.[18]
Overnight between August 24 and August 25, Ioke strengthened into a Category 5 hurricane, the first system originating from the Central Pacific to reach that intensity while still in the Western hemisphere. Ioke then weakened back to a Category 4 while undergoing an eyewall replacement cycle, regaining Category 5 strength on August 26.[19] It is the most intense hurricane ever to develop in the Central Pacific, with a central pressure of 920 mbar (27.17 inHg). Ioke is only the fifth Category 5 hurricane on record in the Central Pacific, and the first one since Hurricane John in 1994.[20]
Hurricane Ileana
- Main article: Hurricane Ileana (2006)
Hurricane Ileana began as a tropical wave that emerged off the coast of Africa on August 8.[21] It entered the Eastern North Pacific on August 16 and convection increased slightly. The system became a low-pressure area on August 19, warranting Dvorak numbers. As the low continued west-northwestward, the disorganized system gained thunderstorm activity on August 20. Deep convection increased greatly in the low, and it became a tropical depression on August 21 near Acapulco.[22] The depression strengthened into Tropical Storm Ileana six hours after forming. Ileana continued to strengthen, becoming a hurricane in 24 hours, and a major hurricane 24 hours after that. Ileana passed to the south of Socorro Island on August 23 as a Category 3 hurricane. Ileana then reached its peak intensity of 120 mph (195 km/h) on the same day, maintaining it overnight. Ileana then commenced into a slow weakening phase on August 24, when it encountered cooler waters. Ileana became a tropical depression on the morning of August 27, degenerating into a remnant low at 1800 UTC. The remnant low continued for two more days, moving slowly westward with winds of 25 mph. The low dissipated on August 29.
As Ileana was heading north along the Mexican coastline, slight rainfall was recorded along the coast.[23] There were also reports of hurricane force winds on Socorro Island.[21] One fatality was reported when a man died from heavy surf near Cabo San Lucas.[24]
Hurricane John
- Main article: Hurricane John (2006)
On August 28, a persistent area of low pressure southwest of Acapulco, Mexico developed into a tropical depression. Later that day it strengthened into a tropical storm, and it reached hurricane strength 24 hours later on August 29. John underwent rapid intensification and reached Category 3 intensity later that day and Category 4 on August 30. Hours later, the hurricane underwent another eyewall replacement cycle,[25] and subsequently weakened to Category 3 status as it paralleled the Mexican coastline a short distance offshore.[26]
Potentially due to its eyewall replacement cycle of its interaction with land, Hurricane John weakened to a 105 mph hurricane by late on August 31,[27] but restrengthened to a major hurricane shortly after. It made landfall near the southern tip of Baja California as a Category 2 hurricane on September 1.[28]
The hurricane caused flooding along the west coast of Mexico and on Baja California. John caused moderate damage and five deaths, with one person missing.
Hurricane Kristy
On August 30, a tropical wave located about 525 miles south-southwest of Baja California became more organized and was designated as the twelfth tropical depression of the 2006 season. It strengthened into Tropical Storm Kristy before the first regular advisory and became Hurricane Kristy the next day. It did not retain this status for long, partly due to its proximity to Hurricane John. It weakened steadily and looked to be close to dissipating, but on September 3, and again on September 5, convection flared up and it returned to tropical storm strength.
Due to Kristy's close proximity to the larger Hurricane John, there was a possibility of a Fujiwhara interaction between both systems, causing Kristy to weaken or perhaps be absorbed into the circulation of John.[29] However, this did not occur. After oscillating between storm and depression strength, the system degenerated into a remnant low on September 7.
Hurricane Lane
- Main article: Hurricane Lane (2006)
On September 13, a tropical disturbance located about 125 miles west-southwest of Acapulco, Mexico, gradually became better organized and was designated the thirteenth tropical depression of the 2006 season. The depression intensified in a favorable environment, and was upgraded to Tropical Storm Lane later that night.
Tropical Storm Lane produced heavy rainfall and high seas along the west coast of Mexico, including Acapulco where flood waters reached 16 inches (40 cm) in depth. The Acapulco airport also experienced flooding, though service was not interrupted. In addition, officials closed the port in Acapulco to small boats.[30] One person was killed in a landslide triggered by Lane.[31]
As it moved parallel to the Mexican coast it continued to strengthen and became a hurricane on September 15, and a major hurricane early the next day. It made landfall on the coast of Sinaloa state on September 16.
Tropical Storm Miriam
A disturbance associated with a northerly extension of the Intertropical Convergence Zone and a tropical wave developed a closed circulation on September 15 while located to the west of Hurricane Lane. It moved northeastward under the influence of Lane, and organized enough to be declared Tropical Depression Fourteen-E on September 16 while located about 500 miles southwest of Cabo San Lucas, Mexico. It quickly strengthened, and organized into Tropical Storm Miriam later that day. After reaching a peak intensity of 45 mph (70 km/h), vertical wind shear and cooler waters rapidly weakened the storm, and the circulation decoupled from the convection on September 17. After turning more towards the north, Miriam weakened to tropical depression status, and on September 18 it degenerated to a remnant low. The remnant circulation turned to the northwest, then to the east, and dissipated on September 21 a short distance west of Baja California. No deaths are damage are associated with Miriam, and only one ship recorded winds of over tropical storm force near the center.[32]
Tropical Depression Two-C
On September 18, an area of disturbed weather became sufficiently organized and was designated Tropical Depression Two-C. The depression weakened into a remnant low on September 20, never reaching tropical storm status.
Tropical Depression Three-C
On September 26, another area of disturbed weather in the Central Pacific, very near the International Date Line became organized and was designated Tropical Depression Three-C. However, wind shear was not favorable, inhibiting development, and the system dissipated 12 hours later, just as the system was crossing into the Western Pacific.
Tropical Storm Norman
Early in October, a low pressure system began to organize better to the west of the coast of Mexico. Late in the evening of October 8, it became Tropical Depression Fifteen-E as the circulation closed. It strengthened slowly overnight and became a tropical storm the next day, but strong wind shear and low sea-surface temperatures hindered development. It slowly began to weaken and on October 10 lost most convection. The remnant low of Norman combined with a new tropical disturbance while southwest of Manzanillo, and slowly began to reorganize. The system was redesignated a tropical depression on October 15, south-southeast of Manzanillo, Colima. Conventional satellite imagery suggests that Norman may have made landfall east of Manzanillo, but as surface observations do not suggest landfall was made, and microwave satellite imagery could not easily track the disorganised depression, the NHC estimates that Norman dissipated over the Pacific as it neared Manzanillo.[33]
Tropical Storm Olivia
Less than a day after the formation of Fifteen-E a second depression formed even further to the south-west from Baja California and was designated Tropical Depression Sixteen-E. It strengthened into Tropical Storm Olivia on October 10, after persistent deep convection. It encountered shearing winds and marginal temperatures and began to weaken the next day, dissipating on October 12. The remnant low became absorbed by the large area of disturbed weather associated with the remnants of Norman.
Tropical Depression Four-C
An area of thunderstorm activity and convection was first spotted in the ITCZ on October 8. Taking a long time to organise, Tropical Depression Four-C formed about 750 miles (1200 km) SW of Honolulu, Hawaii on October 13. Wind shear caused an exposed low-level circulation and therefore advisories were discontinued on October 14. The remnants of TD-4C fuelled heavy rainfall and flooding on Big Island.[34]
Hurricane Paul
- Main article: Hurricane Paul (2006)
On October 21, a tropical disturbance that had lingered for a few days near the Mexican coast quickly developed more convection, enough to strengthen to a tropical depression. The system quickly strengthened and was designated Tropical Storm Paul six hours later. Easterly shear prevented it from strengthening much in the first two days of its existence, but late on October 22 it began to strengthen steadily and became a hurricane. It reached Category 2 with a peak of 105 mph winds before rapidly weakening as it moved northwards, encountering heavy shear and unsuitable conditions on October 23.
While originally forecast to hit the western Mexican coastline as a hurricane, Paul quickly weakened into a tropical storm while southwest of the Baja California peninsula. It steadily moved across the southern areas of the Gulf of California before weakening into a tropical depression a short distance off the Mexican coast. On October 26 it made landfall near the southern end of Isla Altamura and became a remnant low shortly after.
Tropical Depression Eighteen-E
Tropical Depression Eighteen-E formed from a tropical wave that emerged off the coast of Africa on October 7.[35] A low-pressure system became associated with the wave on October 12, 750 nautical miles southwest from the southernmost Cape Verde Islands.[36] However, strong upper-level winds inhibited development of the low-pressure area as it continued westward. The low-pressure area crossed into the Eastern Pacific basin on October 20.[35]
Convection began to come together on October 24, strengthening into a tropical depression two days later.[35] The depression moved to the southwest, encountering wind shear and dry, stable air. Thunderstorm activity lessened in the depression, degenerating into a remnant low on October 28. The remnants continued, dissipating the next day.
Tropical Storm Rosa
A tropical wave emerged off the western coast of Africa on October 22. As the wave traversed the Atlantic Ocean and Caribbean Sea, it was hard to track.[37] On November 3, the wave crossed over Central America and entered the Eastern Pacific Ocean. Shortly afterwards, activity in the wave increased, strengthening into an area of low-pressure on November 5. Convection remained disorganized on November 6, but began to organize the next day. Just after 600 UTC on November 8, the low-pressure area was designated Tropical Depression Nineteen-E. The formation the tropical depression was the first one in November since 2002's Tropical Depression Sixteen-E.[38]
The depression moved slowly northward, gaining the organization for a tropical storm.[37] However, the satillites showed a degenerated area from southwesterly wind shear. Convection reformed on November 9, despite the shear, causing the depression to strengthen into Tropical Storm Rosa. The shear resulted in a halt in organization, as Rosa lost tropical storm status 18 hours later. Tropical Depression Rosa degenerated into an open trough on November 10. Tropical Storm Rosa was the first tropical storm in the Eastern Pacific in November since 2000.[37]
Tropical Depression Twenty-E
A tropical wave emerged off of the western coast of Africa on October 21, while a low-pressure system formed east of the Lesser Antilles on August 25.[39][40] The low went eastward, crossing through the Windward Islands on August 27.[41] The low-pressure area weakened and became tropical wave on August 28.[42] The wave continued westward, passing through the Caribbean Sea. When the wave entered the southwestern Caribbean, it spawned another low-pressure area.[39] The low-pressure area crossed Central America and entered the Eastern Pacific Ocean on November 1.
Convection remained minimal, and the low-pressure area meandered around in dry, stable air.[39] Convection became organized on November 9 for warranting of Dvorak numbers, but the chances quickly diminished. A curving band appeared in the low on November 10, with the low strengthening into Tropical Depression Twenty-E on November 11. The wave never left the Intertropical Convergence Zone and degenerated into an open trough on the same day. Redevelopment of the depression was not anticipated, and it disappeared by the afternoon of November 12.[43]
Hurricane Sergio
- Main article: Hurricane Sergio (2006)
Just days after Tropical Depression Twenty-E degenerated into an open trough, a tropical wave developed into Tropical Depression Twenty-One-E on November 13 about 460 miles (740 km) south of Manzanillo, Mexico, and steadily intensified as it tracked southeastward. Sergio reached peak winds of 110 mph (175 km/h) on November 15, and subsequently began to weaken due to increased wind shear as it turned to the north. Sergio later turned to the west, remaining well off the coast of Mexico, and dissipated on November 20 about 320 miles (515 km) west-northwest of where it originally formed. |
