Staying true to the spirit of 2020, this year’s Atlantic Hurricane Season has been the busiest on record.
After Tropical Storm Theta became the 29th named storm in the Atlantic this year, the US National Hurricane Center announced that 2020 has broken the single-season record for the most named storms, previously held by the 2005 Hurricane Season with 28 storms.
Tropical Storm Theta sealed the deal after becoming a named storm on the evening of November 10. The storm is currently moving over the eastern Atlantic Ocean with maximum sustained winds of up to 104 kilometers (65 miles) per hour.
Storms are named once they hit a wind speed of 62 kilometers (39 miles) per hour. The name is picked from one of six annually rotating lists of 21 names in alphabetical order (avoiding the letters Q, U, X, Y, and Z) created by the World Meteorological Organization. However, this year they exhausted their list of names and were forced to turn to the Greek alphabet, naming storms Alpha, Beta, Gamma, Delta, Epsilon, Zeta, Eta, and Theta.
The Atlantic hurricane season runs from June 1 to November 30, peaking between late August and September. The National Oceanic and Atmospheric Administration (NOAA) predicted that this was likely to be a busy hurricane season back in May. However, the season has surpassed even their most extreme forecasts. On top of this new record, 2020 has also seen 12 storms make landfall in the mainland US, which is three more than the previous record set in 1916.
The rocky hurricane season is likely to be the result of a cocktail of climate factors that are playing out across the planet. The first factor is linked to the El Niño Southern Oscillation, a climate cycle that describes the fluctuations in temperature between the ocean and atmosphere in the east-central Pacific Ocean, which has profound implications for the whole planet's climate and weather. El Niño typically refers to the warm phase, when the Pacific's warmest surface waters sit offshore of northwestern South America, while La Niña refers to the cold phase when there are below-average sea surface temperatures across the east-central Pacific.
El Niño helps to strengthen hurricane activity in the central and eastern Pacific basins while suppressing it in the Atlantic basin. However, the planet saw an ongoing La Niña this year, meaning hurricane activity in the Atlantic was left unsuppressed.
Secondly, as forecasted, this year saw warmer-than-average sea surface temperatures in the tropical Atlantic Ocean and the Caribbean Sea, weaker tropical Atlantic trade winds, and an enhanced west African monsoon. All of these factors are known to increase the likelihood of hurricanes in the Atlantic.
While it’s unclear how this hurricane season was influenced by the world’s deepening climate crisis, it's now known that rising sea surface temperatures from human-driven climate change can fuel the intensity and destructiveness of tropical storms.