2010 Atlantic hurricane season

A hyperactive year driven by La Niña and record-warm water

Twenty storms appear in the archive for 2010, from Alex on 25 June to Tomas on 7 November. Eighteen reached tropical storm strength, twelve became hurricanes and five reached major hurricane intensity of at least 96 knots, though none reached Category 5. Hurricane Danielle, Hurricane Earl, Hurricane Igor and Hurricane Julia all peaked at Category 4, and Hurricane Karl at Category 3. The season's accumulated cyclone energy of 163.9 units was the highest since 2005.

The National Hurricane Center's best track, as summarized on Wikipedia, counts 21 tropical depressions, 19 named storms, 12 hurricanes and 5 major hurricanes, with an accumulated cyclone energy of about 165. The one-storm difference is Tropical Storm Hermine, which formed in the Bay of Campeche from the remnants of an eastern Pacific depression and does not appear among the archive's Atlantic storms for 2010. The archive counts one-minute winds only during each storm's tropical stage within the calendar year, which also accounts for the small gap in accumulated cyclone energy. On either count, the 12 hurricanes matched 1969 for the third-highest total on record at the time, behind only 2005 and, later, 2020.

The drivers lined up almost perfectly for an active year. A strong El Niño in 2009 gave way to a strong La Niña by mid-2010, lowering vertical wind shear over the Atlantic. Sea surface temperatures across the basin reached record levels, and the main development region between Africa and the Caribbean set monthly warmth records from February to October, helped by weak trade winds under a strongly negative North Atlantic Oscillation. Forecasters had called for an active season: NOAA's May outlook projected 14 to 23 named storms, and Colorado State University raised its forecast to 18 named storms and 10 hurricanes by June. Dry mid-level air over the tropical Atlantic during the peak months may have kept the season from being busier still.

A slow start, then a relentless peak

The season opened with Hurricane Alex, which formed in the northwestern Caribbean on 25 June, crossed Belize and the Yucatán Peninsula as a tropical storm, and strengthened over the Gulf of Mexico to become the first June hurricane since 1995. July was quiet, with only a tropical depression that came ashore on South Padre Island, Texas, and the small Tropical Storm Bonnie, which crossed the Bahamas and South Florida. Early August added the short-lived Tropical Storm Colin and a depression in the eastern Gulf of Mexico west of Fort Myers.

The season turned in the last third of August. Hurricane Danielle formed west of Cabo Verde on 21 August and was followed four days later by Hurricane Earl, which formed off the African coast; both became Category 4 hurricanes. Tropical Storm Fiona trailed Earl toward the northern Leeward Islands before being torn apart by Earl's outflow, and Tropical Storm Gaston formed on 1 September before dry air smothered it.

September was the busiest month, with eight named storms in the best track, tying 2002 and 2007 for the most on record at the time. Hurricane Igor, Hurricane Julia and Hurricane Karl were hurricanes simultaneously on 16 September, Igor and Julia over the open Atlantic and Karl in the Bay of Campeche. Hurricane Lisa, Tropical Storm Matthew and Tropical Storm Nicole closed out the month. October brought five more hurricanes: Otto, which began as a subtropical storm north of Puerto Rico, Paula, Richard, the small Hurricane Shary near Bermuda, and Tomas, whose final tropical-stage fix on 7 November ended the season.

Four Category 4 hurricanes and a record in the Bay of Campeche

Hurricane Igor was the strongest and longest-lived storm of the year. It formed southeast of Cabo Verde on 8 September, became a hurricane on 12 September and, after rapid intensification and an eyewall replacement, peaked at 135 knots with a central pressure of 924 hPa on 15 September. Igor stayed a Category 4 hurricane for several days over the central Atlantic before shear and dry air weakened it on its way north past Bermuda.

Hurricane Earl peaked at 125 knots and 927 hPa on 2 September after passing just north of the Leeward Islands, then weakened as it paralleled the United States East Coast. Hurricane Julia reached 120 knots on 15 September far out in the eastern Atlantic, becoming the strongest hurricane in the best-track record east of 40 degrees west. Hurricane Danielle peaked at 115 knots on 27 August south-southeast of Bermuda without threatening land.

Hurricane Karl was the season's fifth major hurricane and the most unusual. After crossing the Yucatán Peninsula as a tropical storm, it rapidly intensified over the Bay of Campeche to 110 knots on 17 September, the strongest hurricane and the only major hurricane on record there, and was still a major hurricane when it made landfall northwest of Veracruz later that day.

Floods across Mexico, Central America and the Caribbean

Hurricane Alex made its final landfall at its 95-knot peak near Soto la Marina in Tamaulipas on 1 July, one of the most intense June cyclones in the Atlantic record. Its torrential rain did the most harm, flooding Monterrey and washing out bridges and streets. The National Hurricane Center's report attributes 12 direct deaths in Nuevo León to Alex and gives a rough media-based estimate of 1.5 billion US dollars (2010) in damage in Mexico. Two months later, Tropical Storm Hermine came ashore near Matamoros and dropped up to 16.37 inches of rain in central Texas; the report lists six deaths in Texas and Oklahoma and estimates damage at 240 million US dollars (2010), double the insured losses.

Mexico and Central America were hit again in September. Hurricane Karl's landfall near Veracruz flooded more than 20,000 homes and left more than 40,000 people homeless; media reports cited in the National Hurricane Center's report put the death toll at 22, most of them in Veracruz. Tropical Storm Matthew moved ashore near the Nicaragua and Honduras border on 24 September and later into Belize, and its rains were linked to 78 deaths according to media reports, 65 of them in Nicaragua, with further deaths in Honduras, Mexico and El Salvador.

Tropical Storm Nicole was brief and weak but devastating in Jamaica, where the government reported 13 deaths from flooding and estimated infrastructure repairs at about 235 million US dollars (2010). In October, Hurricane Richard made landfall near Gales Point, Belize, at 85 knots, causing one direct and one indirect death and more than 80 million US dollars (2010) in reported damage, much of it to the citrus crop. Hurricane Paula stayed offshore at its peak and struck western Cuba as a tropical storm, and a swimmer drowned in rough surf off Cancún.

Hurricane Tomas was the deadliest storm of the season in the Caribbean. It crossed Barbados on 30 October and struck St. Lucia as a hurricane, where eight people died and damage reached an estimated 336.15 million US dollars (2010). It later brought floods and mudslides to Haiti, still recovering from the January 2010 earthquake, where 35 people died. The National Hurricane Center's report puts Tomas's total at 44 deaths across the Lesser and Greater Antilles.

Farther north, the Cape Verde hurricanes caused harm mostly through surf and swell. Rough seas from Hurricane Earl claimed five lives along the United States East Coast and in Nova Scotia, where Earl made landfall near Liverpool as a 65-knot hurricane on 4 September; the report estimates Earl's damage at about 45 million US dollars (2010), with the heaviest losses in Antigua and Barbuda and North Carolina. Hurricane Igor made landfall near Cape Race, Newfoundland, on 21 September. The Canadian Hurricane Centre called it Newfoundland's most damaging hurricane in 75 years: floods washed out roads and bridges and cut off whole peninsulas, one man died, and preliminary damage there was put at almost 200 million US dollars (2010). Igor's swells also drowned two people in Puerto Rico and St. Croix.

Records and retired names

Despite 12 hurricanes, none made landfall in the United States; 2010 remains the only year in the Atlantic database with more than 10 hurricanes and no United States hurricane landfall. Hurricane Tomas became the latest hurricane on record in a calendar year to strike the Windward Islands, and Hurricane Shary was a small hurricane that the National Hurricane Center said would probably have gone unnoticed before microwave satellite imagery. The Atlantic also produced more tropical storms than the western Pacific in 2010, only the second time that has happened, after 2005.

In March 2011 the World Meteorological Organization retired the names Igor and Tomas because of the damage and deaths they caused. They were replaced by Ian and Tobias on the list used again in 2016.