With contributions from Lixion Avila, Robbie Berg, Michael Brennan, Dan Brown, John Cangialosi, Todd Kimberlain, Richard Pasch, and Stacy Stewart
The 2010 Atlantic hurricane season featured 19 tropical storms, of which 12 became hurricanes (Figure 1 and Table 1). These numbers make 2010 the second most active season since relatively reliable records began in the late 1960s. Five of the hurricanes became major hurricanes, category 3 or higher on the Saffir-Simpson Hurricane Wind Scale. There were two additional tropical depressions. The accumulated cyclone energy (ACE) index was 190 percent of the long-term median. The active season likely resulted from very warm sea surface temperatures and low vertical wind shear in the tropical Atlantic and the Caribbean Sea between West Africa and Central America, combined with the change in Pacific Ocean conditions from El Niño in 2009 to La Niña in 2010.
Table: Table 1. Summary of Activity of the 2010 Atlantic Hurricane Season
Maximum winds (mph)
Minimum pressure (mb)
U.S. damage ($ million)
June 25–2 July
August 25–September 4
August 30–September 3
October 29–November 7
Caption: MODIS image of Hurricane Earl off the southeastern coast of the United States on September 2, 2010.
Despite the high level of activity, no hurricanes struck the United States during 2010. This was the most active season of record in the Atlantic that did not feature a United States landfalling hurricane. This is attributed to a persistent trough of low pressure near the United States East Coast that diverted most storms originating east and southeast. In addition, cyclones south of the United States were mostly steered into Central America and Mexico by a persistent ridge of high pressure over the northwestern coast of the Gulf of Mexico.
A seasonal highlight was a series of experiments involving research aircraft from NOAA, NASA, and the National Science Foundation that monitored the entire life cycle of several Atlantic storms. The data collected during the experiments were of great value to the National Hurricane Center, both during and after the storms.
In the individual storm descriptions that follow, all dates and times are based on Universal Coordinated Time (UTC). Damage figures, when available, are given in United States dollars.
Alex formed from a disturbance in the Atlantic Intertropical Convergence Zone (ITCZ) that was first noted on June 17. A low pressure area developed on June 24 over the northwestern Caribbean, and a tropical depression formed the next day about 90 miles north-northeast of Puerto Lempira, Honduras. The depression strengthened into a tropical storm with 65-mph winds before making landfall near Belize City, Belize, around 0000 UTC on June 27.
Caption: This home in Roma, Texas, photographed on July 24, 2010, was flooded after Hurricane Alex. Some communities in Roma were flooded with more than three feet of water.
Alex crossed Belize and the southern Yucatan Peninsula of Mexico, and entered the southwestern Gulf of Mexico on June 28. Over the Gulf, the cyclone grew in both strength and size, and it reached hurricane strength on June 30. The hurricane made landfall around 0200 UTC on July 1 near Soto la Marina, Mexico, with sustained winds of 110 mph—category 2 on the Saffir-Simpson Hurricane Wind Scale, making Alex the strongest June hurricane since Alma of 1966. Alex weakened after landfall and dissipated over central Mexico the next day.
There were no official observations from the landfall area in Mexico. Port Isabel, Texas, reported six-minute mean winds of 51 mph and a peak gust of 62 mph. The main impact of Alex was heavy rainfall, with estimates of 20 inches or more over northeastern Mexico and five to ten inches in Texas. These rains caused widespread flooding, especially in the Mexican state of Nuevo León, where the city of Monterrey was hard hit. Severe flooding also occurred along the Rio Grande River. In addition, the hurricane produced nine tornadoes in Texas. In Mexico, Alex directly caused 12 deaths and estimated property damage of $1.5 billion. Two deaths also occurred in Guatemala.
Tropical Depression Two
This short-lived system formed early on July 8 from a tropical wave about 290 miles southeast of Brownsville, Texas, and it made landfall near Port Isabel, Texas, around 1400 UTC that day. Thereafter, the cyclone moved into northeastern Mexico where it dissipated on July 10. The depression caused locally heavy rains over southern Texas and northeastern Mexico, which aggravated ongoing flooding in these areas caused by Hurricane Alex.
Tropical Storm Bonnie
A tropical wave spawned a low pressure area early on July 22 near the southeastern Bahamas, and soon thereafter a tropical depression formed from the low near Acklins Island in the central Bahamas. The cyclone became a tropical storm early the next day, and maximum sustained winds reached 45 mph as the center passed over Andros Island in the northwestern Bahamas. Bonnie made landfall around 1430 UTC on July 23 near Elliot Key, Florida, and weakened to a tropical depression over southern Florida. Unfavorable upper-level winds over the Gulf of Mexico caused Bonnie to degenerate to a remnant low on July 25 over the northern Gulf, with the low dissipating over eastern Louisiana later that day.
Fowey Rocks, Florida, reported 10-minute mean winds of 47 mph and a peak gust of 56 mph, while Mangrove Cay in the Bahamas reported sustained winds of 43 mph. Bonnie caused minor impacts in the Bahamas and southern Florida.
Tropical Storm Colin
Two tropical waves and a surface trough of low pressure interacted to produce Colin. The cyclone formed on August 2 and intensified into a tropical storm early on August 3. Strengthening then stopped, and later that day the storm degenerated to a trough of low pressure, even though it retained tropical-storm force winds. The system passed to the northeast of the Leeward Islands on August 4 and regained tropical-storm status the next day when it redeveloped a closed circulation. Colin reached a peak intensity of 60 mph later that day, after which it gradually weakened. It became a tropical depression early on August 8, and it again degenerated to a trough later that day about 115 miles southwest of Bermuda. Some squally weather occurred on Bermuda before the trough dissipated on August 9.
Caption: Tracks of Atlantic tropical storms and hurricanes during 2010.
Tropical Depression Five
A decaying frontal system spawned a low pressure area over the western Atlantic, which crossed the Florida Peninsula into the eastern Gulf of Mexico. The low was a tropical depression for about 12 hours on August 9 and 10 before degenerating back to a low pressure area. The low then followed a looping track over the northern Gulf of Mexico and the Gulf Coast states before dissipating over southwestern Mississippi on August 18. The system caused locally heavy rains over portions of the northern Gulf coast, with rainfall totals up to 10 inches in parts of eastern Louisiana and southwestern Mississippi.
Danielle had a complex origin over the eastern tropical Atlantic involving a tropical wave and an active ITCZ. The two systems combined to form a large low pressure area on August 20, which in turn spawned a tropical depression the next day about 520 miles west-southwest of the Cape Verde Islands. The depression became a tropical storm about 12 hours later and a hurricane on August 23. After an encounter with an upper-level trough halted its development, Danielle intensified again on August 26, reaching an estimated peak intensity of 135 mph late on August 27. The cyclone recurved into the westerlies during August 28 and 29 and weakened to a tropical storm on August 30. Extratropical transition occurred the next day, and the former hurricane dissipated several hundred miles east-southeast of southern Greenland on September 3.
Danielle did not directly impact land. However, swells from the hurricane reached the east coast of the United States and caused one death.
A strong tropical wave spawned a low pressure system southeast of the Cape Verde Islands on August 24. The low developed into a tropical depression and then a tropical storm on August 25. Gradual strengthening over the next several days led to Earl becoming a hurricane on August 29 as it approached the Leeward Islands. Rapid intensification ensued, and Earl became a major hurricane just north of the northern Leeward Islands on August 30. After undergoing an eyewall replacement cycle, the hurricane reached its peak intensity of 145 mph on September 1.
On September 3, Earl moved northeastward parallel to, but offshore of, the east coast of the United States. The system briefly weakened to a tropical storm, but then strengthened back to a category 1 hurricane before making landfall near Liverpool, Nova Scotia, around 1500 UTC September 4. Earl then crossed Prince Edward Island as a tropical storm and became extratropical over the Gulf of St. Lawrence early on September 5. The extratropical low merged with another low over the Labrador Sea the next day.
Caption: Hurricane Earl as seen from the International Space Station on August 30.
NOAA buoy 41046 reported 10-minute mean winds of 82 mph with a peak gust of 100 mph as the eye of Earl passed over it on September 3. In Nova Scotia, McNabs Island and Osbourne Head reported 10-minute mean winds near 65 mph. Tropical-storm force winds were also reported in the northern Leeward Islands, the Virgin Islands, Puerto Rico, and the Outer Banks of North Carolina. The storm produced locally heavy rains over the Caribbean islands and portions of the United States east coast.
Earl caused five deaths by drowning in dangerous surf conditions—four along the United States East Coast and one in Nova Scotia. The total property damage is estimated at $45 million, with $18 million of that occurring in the United States.
Caption: Hurricane warning flags for Hurricane Earl at a lighthouse in Chatham, Massachusetts on September 3, 2010.
Tropical Storm Fiona
Fiona originated from a large and convectively active tropical wave that slowly developed over the tropical Atlantic. On August 30, a tropical depression formed about 1,035 miles east of the Lesser Antilles, and it became a tropical storm later that day. Fiona's center passed about 65 miles to the northeast of Barbuda in the Leeward Islands on September 1 just before the storm reached an estimated peak intensity of 65 mph. After that, outflow from the much larger Hurricane Earl caused Fiona to weaken. The cyclone degenerated into a post-tropical low about 110 miles south of Bermuda on September 4 and dissipated northeast of Bermuda the next day.
Tropical Storm Gaston
A tropical wave spawned Gaston, which was a minimal tropical storm for only 12 hours over the tropical Atlantic on September 1. The cyclone degenerated to a remnant low the next day, and persisted until dissipating over the Caribbean on September 8. National Science Foundation flight data suggest Gaston's demise may have been due to ingestion of very dry air.
Tropical Storm Hermine
Hermine developed from the remnants of eastern Pacific Tropical Depression Eleven-E, which made landfall on the Pacific coast of Mexico on September 4. The remnants moved into the southern Bay of Campeche and redeveloped into a tropical depression late on September 5. After strengthening to a tropical storm early the next day, Hermine reached an estimated peak intensity of 70 mph at landfall in northeastern Mexico around 0200 UTC on September 7. The storm crossed the Rio Grande into the United States a few hours later and maintained tropical-storm intensity until the center reached central Texas early on September 8. The cyclone then weakened to a depression, and it subsequently degenerated to a remnant low over Oklahoma. The low dissipated over southeastern Kansas early on September 10.
Caption: Wind damage from Tropical Storm Hermine in Kingsville, Texas.
Harlingen, Texas, reported two-minute mean winds of 59 mph and a peak gust of 72 mph. The storm produced locally heavy rains over portions of Texas and Oklahoma, with a storm total of 16.27 inches reported at Georgetown Lake, Texas. In addition, the storm caused two tornadoes in central and northern Texas. Six people died due to Hermine, including one drowning in a coastal rip current and five drowning deaths in freshwater floods. Hermine was the costliest United States tropical cyclone of 2010, with property damage estimated at $240 million.
The monstrous Igor first became a tropical storm on September 8 southeast of the southern Cape Verde Islands. The cyclone briefly weakened to a tropical depression on September 9 before regaining tropical-storm strength the next day. Igor strengthened to a major hurricane on September 12, and it would maintain this status for the next five days with a peak intensity of 155 mph on September 15. The storm also grew in size, with the associated tropical-storm-force winds covering an area about 500 miles in diameter by September 17 and about 850 miles in diameter by September 20. Igor's center passed about 40 miles west of Bermuda early on September 20, at which time it was a Category 1 hurricane. The hurricane accelerated toward Newfoundland on September 20 and 21, and the center passed over the southeastern end of the Avalon Peninsula around 1500 UTC on September 21. Shortly thereafter, Igor became a hurricane-force extratropical low, and it was absorbed into another low pressure system early on September 23 over the Labrador Sea.
Caption: Hurricane Igor from the International Space Station.
St. David's on Bermuda reported 10-minute mean winds of 91 mph and a gust of 117 mph at an elevation of 159 feet. Hurricane conditions also occurred in Newfoundland, where Bonavista reported 10-minute mean winds of 76 mph and Cape Pine reported a gust of 107 mph. Widespread wind and flood damage estimated at $200 million was reported in Newfoundland, and one death was reported there. Minor damage to property was reported on Bermuda. Large swells generated by the hurricane caused two drowning deaths from high surf—one in Puerto Rico and one in St. Croix.
Julia formed from a vigorous tropical wave that developed immediately upon reaching the Atlantic. A tropical depression formed from the wave early on September 12 about 290 miles south-southeast of the southernmost Cape Verde Islands. It became a tropical storm 12 hours later. Julia reached hurricane intensity on September 14, and then rapidly strengthened to an estimated peak intensity of 140 mph the next day. After that, Julia weakened as it encountered an upper-level low and the outflow of the vastly larger Hurricane Igor. Julia recurved to the east of Igor, and by September 17 it weakened to tropical-storm strength. The cyclone degenerated to a convectionless low late on September 20, about 1100 miles west of the Azores Islands. The low slowly weakened for several more days while it turned southward and then westward, degenerating into an open trough on September 24.
Julia is the strongest Atlantic hurricane on record east of 40°W. However, it is unlikely that its peak intensity or its 1.25 day duration as a major hurricane would have been observed for a hurricane in this location before the advent of regular satellite imagery and the Dvorak intensity analysis technique in the 1970s. While there were no reports of tropical-storm-force winds from Julia, it is possible they occurred in the southern Cape Verde islands.
On September 9, a tropical wave interacted with a trough of low pressure extending northeastward from northeastern South America. The resulting low pressure area crossed the Caribbean Sea and became a tropical depression on September 14 about 375 miles east of Chetumal, Mexico. The cyclone became a tropical storm six hours later, and the system's maximum sustained winds increased to 65 mph before Karl made landfall on the Yucatan Peninsula around 1245 UTC on September 15.
Karl remained well organized over land, and rapid intensification started when the center reached the Bay of Campeche in Mexico early on September 16. It became a hurricane later that day, became a major hurricane early on September 17, and reached a peak intensity of 125 mph a few hours after that. This made Karl the first major hurricane on record in the Bay of Campeche. The category 3 hurricane made landfall just northwest of Veracruz, Mexico, around 1645 UTC on September 17. Post-landfall weakening led to Karl dissipating completely over the mountains of central Mexico on September 18.
An automated station in the harbor at Veracruz reported 10-minute mean winds of 66 mph and a gust of 94 mph. Karl was responsible for 14 deaths, and the damage to property is estimated at $206 million.
A broad low pressure area associated with a tropical wave was noted southwest of the Cape Verde Islands on September 18. Slow development followed, and a tropical depression formed on September 20 about 460 miles west of the Cape Verde Islands. The cyclone fluctuated in strength for a couple of days, becoming a tropical storm on September 21 and weakening to a depression the next day. Lisa regained tropical storm strength on September 23, and it became a hurricane the following day with the estimated maximum winds reaching 85 mph. Rapid weakening followed, and Lisa degenerated to a remnant low by the end of September 26. The remnants moved northward and northwestward before dissipating south-southwest of the Azores on September 29.
Tropical Storm Matthew
The southern portion of the tropical wave that spawned Hurricane Julia moved into the Caribbean Sea and spawned another low pressure area on September 22. On September 24, this system became a tropical depression about 565 miles east of Cabo Gracias a Dios on the Nicaragua/Honduras border, and it became a tropical storm shortly thereafter. Matthew reached a peak intensity of 60 mph before making landfall about 25 miles south of Cabo Gracias a Dios near 1900 UTC on September 24. It then crossed northeastern Nicaragua and Honduras and moved into the Gulf of Honduras. A final landfall occurred about 15 miles north-northeast of Monkey River Town, Belize, about 1500 UTC on September 25. Matthew weakened to a remnant low over eastern Mexico on September 26, and the surface circulation dissipated later that day.
Puerto Lempira, Honduras, reported a 10-minute mean wind of 46 mph at 2300 UTC on September 24. The main impact of Matthew was widespread heavy rains that caused floods and mudslides. A storm total of 16.73 inches fell at Acayucan in the Mexican state of Veracruz, and five to 10 inch totals were common elsewhere in eastern Mexico. Storm totals of four to eight inches occurred over portions of Nicaragua and Honduras. Matthew, the deadliest storm of the 2010 season, caused 78 deaths: 65 in Nicaragua, eight in Mexico, four in Honduras, and one in El Salvador.
Tropical Storm Nicole
A broad low pressure area became evident on September 26 in a vigorous ITCZ or monsoon trough over the western Caribbean Sea. On September 28, a tropical depression formed south of western Cuba, and the depression strengthened slightly into a tropical storm later that day. The center of Nicole lost organization as it crossed central Cuba on September 29, and the cyclone degenerated to a low pressure area. The low became extratropical near south Florida and the northwestern Bahamas on September 30 and dissipated later that day.
Caption: Floodwater remains in some areas of New Bern, North Carolina, on October 6, 2010, after rains caused by the remnants of Tropical Storm Nicole.
Nicole more resembled a monsoon cyclone of the Indian Oceaan or western North Pacific Ocean than a typical Atlantic tropical cyclone, with the strongest winds and heaviest rains well removed from the center. Nicole's main impact was widespread heavy rains over southern Florida, central and eastern Cuba, Jamaica, and the Cayman Islands. The associated floods killed 14 people in Jamaica.
Otto originated from a tropical wave interacting with an upper-level trough. A well-defined surface circulation formed under the upper-level trough on October 6 about 265 miles north-northwest of San Juan, Puerto Rico, resulting in the formation of a subtropical depression. The depression subsequently strengthened to a subtropical storm shortly thereafter. Otto evolved from a subtropical to a tropical storm on October 7 and became a hurricane on October 8, reaching an estimated peak intensity of 85 mph later that day. The cyclone weakened to a tropical storm late on October 9 and lost tropical characteristics on October 10 about 1,035 miles east-northeast of Bermuda. The remnants of Otto gradually weakened over the eastern Atlantic for the next several days before dissipating on October 18.
Otto and its precursor disturbance caused widespread heavy rains over the islands of the northeastern Caribbean, with storm totals exceeding 15 inches. The rains caused damaging floods and mudslides in portions of Puerto Rico, the United States Virgin Islands, and the British Virgin Islands.
A complex series of weather systems resulted in the formation of a tropical depression early on October 11 about 115 miles southeast of Cabo Gracias a Dios. The depression strengthened to a tropical storm before the center crossed over Cabo Gracias a Dios at about 1200 UTC that day. Moving into the northwestern Caribbean, Paula became a hurricane on October 12, and it reached a peak intensity of 105 mph later that day. After that, a weakening Paula moved into the Yucatan Channel. The cyclone made landfall as a 65-mph tropical storm in the Pinar del Rio province of Cuba around 1500 UTC on October 14. The system rapidly weakened as it moved through western Cuba and it completely dissipated by late on October 15.
La Palma, Cuba, reported one-minute mean winds of 51 mph and a peak gust of 68 mph, and Bahía Honda in Pinar del Rio reported 7.32 inches of rain. The storm caused one fatality—a drowning in rough surf at Cancun, Mexico. Property damage from Paula was relatively minor.
Even at its peak intensity, Paula was a small hurricane. The eye of Paula passed within 60 miles of NOAA buoy 42056, and the buoy did not report tropical-storm-force winds, even in gusts.
A long-lived area of disturbed weather over the Caribbean and a tropical wave spawned a low pressure area north of Cabo Gracias a Dios on October 19. The next day, the low became a tropical depression about 195 miles north of Cabo Gracias a Dios. While finishing a half-loop, the depression became a tropical storm on October 21. Richard subsequently became a hurricane on October 24 before passing just north of the Bay Islands of Honduras. The hurricane made landfall as a category 2 hurricane with estimated 100 mph winds near Gales Point, Belize, around 0040 UTC on October 25. The cyclone weakened over land and eventually dissipated over the Bay of Campeche on October 26.
An observer near Orange Walk, Belize, reported one-minute mean winds of 52 mph and a gust of 92 mph. Roatan in the Bay Islands reported a storm total rainfall of 7.64 inches. Richard caused one direct death when a boat capsized in the landfall area in Belize. Property and agricultural damage in Belize is estimated at near $80 million.
The interaction of a frontal system and an upper-level trough caused the formation of a broad area of low pressure, which in turn developed into a tropical depression about 520 miles south-southeast of Bermuda on October 28. The depression reached tropical-storm strength a few hours later, and it was a hurricane for a short time on October 30 before merging with a cold front. The system completely dissipated soon thereafter.
A tropical wave first showed signs of organization over the tropical Atlantic on October 27, and it initiated a tropical depression two days later about 500 miles southeast of Barbados. The cyclone rapidly intensified into a hurricane before reaching the Windward Islands late on October 30. Tomas reached an estimated peak intensity of 100 mph over the southeastern Caribbean early on October 31, then it weakened due to increasing shear and dry air entrainment. Tomas weakened to a tropical storm on November 1, and it meandered across the central Caribbean for the next couple of days.
Late on November 4, Tomas re-intensified. It regained hurricane strength on November 5 while the center passed between Jamaica and the southwestern peninsula of Haiti, with the maximum winds reaching 85 mph a few hours later. The center then moved through the Windward Passage between Haiti and Cuba. Tomas weakened to a tropical storm as the center moved through the southeastern Bahamas and the Turks and Caicos Islands early on November 6. After passing the Bahamas, it regained hurricane status for the third time. Tomas again weakened to a tropical storm before merging with a cold front on November 8, and the resulting extratropical low persisted over the western Atlantic until it was absorbed into another low to the south of Newfoundland on November 11.
Hewanorra Airport on St. Lucia reported 10-minute mean winds of 89 mph with a gust to 98 mph, while Desraches on St. Lucia reported a storm-total rainfall of 26.30 inches. Tomas caused significant damage to property on St. Lucia and Barbados, with 1200 homes damaged on Barbados. The cyclone also produced heavy rains in Haiti, which killed an estimated 35 people and complicated the ongoing earthquake relief efforts in that country.
JOHN L. BEVEN II is a senior hurricane specialist at the National Hurricane Center, where he has worked since 1993.
ERIC BLAKE is a hurricane specialist at the National Hurricane Center, where he has worked since 2002. Much of the international data in this report was provided by the various National Meteorological Services of the countries affected by the 2010 Atlantic tropical cyclones.