Pre-season forecasts by the NOAA – the official forecasting agency for the northern Atlantic – predicted a generally average season, citing the return of the Pacific Decadal Oscillation and a forecast weak El Niño, which inhibits tropical cyclone activity in the basin. Other prediction consortiums also projected a generally average season. However, an unexpected improvement in cyclogenic conditions in the Atlantic resulted in raised forecasts. Colorado State University projected the least active season, with 12 named storms, 5 hurricanes, and 2 major hurricanes,[nb 1] while the NOAA projected the most active season in their mid-season outlook, with 13–18 named storms, 6–12 hurricanes, and 3–4 major hurricanes. Effects of tropical cyclones on land during the year were widespread, though damage was heavily concentrated on Central America, particularly Belize and Nicaragua. The first storm of the season, Arthur, impacted areas of the Lesser Antilles in mid-June. Hurricane Fay in early August brought severe flooding to areas of the Isthmus of Tehuantepec, resulting in 251 deaths, the most for the region since Hurricane Stan in 2005. The strongest tropical cyclone during the season, Marco, reached Category 5 hurricane intensity before striking Puerto Rico and Hispaniola, causing extensive damage and over a thousand deaths. The costliest and deadliest hurricane of the season was Hurricane Nicholas, which impacted Central America and Florida, causing $16 billion in damage and 2,301 deaths. Collectively, storms during 2020 caused $56.5 billion in damage and 5,702 fatalities,[nb 2] making it the costliest hurricane season since 2012 and the deadliest hurricane season since 1998. Seasonal forecasts[]
In advance of, and during, each hurricane season, several forecasts of hurricane activity are issued by national meteorological services, scientific agencies, and noted hurricane experts. These include forecasters from the United States NOAA's National Hurricane and Climate Prediction Center's, Philip J. Klotzbach, William M. Gray and their associates at CSU, Tropical Storm Risk, and the United Kingdom's Met Office. The forecasts include weekly and monthly changes in significant factors that help determine the number of tropical storms, hurricanes, and major hurricanes within a particular year. As stated by NOAA and CSU, an average Atlantic hurricane season between 1981–2010 contains roughly 12 tropical storms, 6 hurricanes, 3 major hurricanes, and an Accumulated Cyclone Energy (ACE) Index of 66–103 units. NOAA typically categorizes a season as either above-average, average, of below-average based on the cumulative ACE Index; however, the number of tropical storms, hurricanes, and major hurricanes within a hurricane season is considered occasionally as well. Pre-season forecasts[]On December 7, 2019, Tropical Storm Risk (TSR), a public consortium consisting of experts on insurance, risk management, and seasonal climate forecasting at University College London, issued an extended-range forecast predicting an average hurricane season. In its report, TSR noted that tropical cyclone activity could be about 2% above the 1950–2010 average, with 12.2 (±4.4) tropical storms, 6.4 (±3.7) hurricanes, and 1.3 (±0.8) major hurricanes anticipated, and a cumulative ACE index of 102 (±64). Later that month on December 21, Weather Services International (WSI) issued an extended-range forecast predicting a near average hurricane season. In its forecast, WSI noted that an unprecedented return of the Pacific Decadal Oscillation beginning in 2018, combined with a forecast strengthening El Niño, would result in a near-average season with 13 named storms, 7 hurricanes, and 3 major hurricanes. They also predicted an above-average probability of a hurricane landfall, with a heavily elevated chance on the Greater Antilles and a slightly reduced chance along the East Coast of the United States, citing a stronger Bermuda High. On April 4, 2020, Colorado State University (CSU) issued their updated forecast for the season, calling for a below-normal season due to an increased chance for the development of an El Niño during the season. In April 2012, TSR issued their update forecast for the season, slightly raising their forecast due to a large model spread for El Niño projections. On May 24, 2020, the NOAA released their forecast for the season, which echoed the sentiment of prior forecasts. The agency predicted a near-normal season, with eleven to fourteen named storms, four to six hurricanes, and one to two major hurricanes. The NOAA based its forecast on higher wind shear and cooler sea surface temperatures in the Main Development Region of the Eastern Atlantic. Gerry Bell, lead seasonal forecaster at NOAA's Climate Prediction Center, added the main uncertainty in the outlook was how much below or above average the 2020 season would be, and if the neutral El Niño/Southern Oscillation would strengthen or weaken to a La Niña. That same day, the United Kingdom Met Office (UKMO) issued a forecast of a slightly above average season. They predicted 14 named storms with a 70% chance that the number would be between 7 and 16. However, they do not issue forecasts on the number of hurricanes and major hurricanes. They also predicted an ACE index of 112 with a 70% chance that the index would be in the range 35 to 167. On May 30, 2012, the Florida State University for Ocean-Atmospheric Prediction Studies (FSU COAPS) issued its annual Atlantic hurricane season forecast. The organization predicted 15 named storms, including 8 hurricanes, and an ACE index of 124. Mid-season forecasts[] Official NHC track map of the season On June 1, Klotzbach's team issued their updated forecast for the 2020 season, predicting fifteen named storms and seven hurricanes, of which four of the seven would further intensify into major hurricanes. The university stated that there was an unexpected warming of Atlantic sea surface temperatures, and a high amount of uncertainty concerning whether the neutral ENSO conditions would continue to decrease or further develop in time to hinder tropical development in the Atlantic. They also stated there was a generally average chance of a major hurricane impacting the United States coastline in 2020. On June 6, Tropical Storm Risk released their second updated forecast for the season, predicting seventeen named storms, eight hurricanes, and five major hurricanes. In addition, the agency called for an Accumulated Cyclone Energy index of 135. Above average sea surface temperatures and lesser wind shear was cited for increased activity compared to previous seasons. Tropical Storm Risk continued with their forecast of a near-average probability of a United States impact during the season using the 1950–2011 long-term normal, and a near-average chance of a United States landfall by the recent 2002–2011 normal. On August 9, 2020, the NOAA issued their mid-season outlook for the remainder of the 2020 season, drastically upping their final numbers. The agency predicted between thirteen and eighteen named storms, six to twelve hurricanes, and three to four major hurricanes. Gerry Bell cited warmer-than-normal sea surface temperatures and lesser than average wind shear. Season summary[] Storms[]Tropical Storm Arthur[]
As it moved through the Lesser Antilles on June 21, Arthur brought widespread rainfall. Precipitation peaked at 5.12 in (130 mm) at Grantley Adams International Airport in Barbados. Though this precipitation was generally light, the ground was already well saturated by prior tropical waves, resulting in localized flooding which damaged some residences. In Grenada, strong winds, which peaked at 48 mph (77 km/h), caused widespread power outages. Downed utility poles resulted in some localized urban fires. As a weakening tropical cyclone, Arthur passed north of the ABC islands, causing light rainfall. However, damage was minimal. Overall, Arthur caused $80,000 in damage, and no deaths resulted. Tropical Storm Bertha[]
As a precursor disturbance and tropical depression, Bertha brought light to moderate rainfall to areas of the Yucatán Peninsula, benefiting an ongoing drought there. Upon landfall on the Tampa Peninsula, Bertha became the first tropical cyclone of tropical storm intensity to directly strike the peninsula from the west since the fourth storm of 1899. As much of the rain was concentrated to the north of the circulation center, torrential rain fell in northern portions of the state, causing widespread flooding. Overall, the storm caused $200,000 in damage and two deaths, both offshore the western Florida coast. Hurricane Cristobal[]
Tropical Storm Dolly[]
Tropical Storm Edouard[]
Hurricane Fay[]
Hurricane Gonzalo[]
Hurricane Hanna[]
Tropical Depression Nine[]
In mid- to late August, a strong cold front moved off the East Coast of the United States. As it drifted eastward, it eventually became stationary while situated between Bermuda and North Carolina. As the front became diffuse, a small low-pressure area formed in the vicinity of Bermuda. Due to nearby Hurricane Gonzalo, the low-pressure failed to organize. However, on August 20, a burst of convection associated with the low-pressure system once Gonzalo had passed to the north had allowed the National Hurricane Center to classify the system as a tropical depression at 1200 UTC that day. Due to the outflow associated with the nearby hurricane, the center of circulation of Tropical Depression Nine remained exposed throughout its lifetime. The following day, however, an increase of shear caused the main convective cell to separate from the circulation center, and the depression was declared to have dissipated at 1200 UTC on August 21. Tropical Storm Isaias[]
Hurricane Josephine[]
Hurricane Kyle[]
Was considered the worst hurricane to impact the Corpus Christi areas since Hurricane Celia. Tropical Storm Laura[]
First named tropical cyclone to make landfall on Costa Rica. Storm names[]
Retirement[]Season effects[]The following table lists all of the storms that formed in the 2020 Atlantic hurricane season. It includes their duration, names, landfall(s)–denoted by bold location names–damages, 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.
See also[]Notes[]
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2020 Atlantic hurricane season (CobraStrike)
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