The brutal 2020 Atlantic hurricane season has officially ended, after generating an extraordinary 30 named storms (highest on record), 13 hurricanes (second highest on record), and six major hurricanes (tied for second highest on record). But fittingly, the busiest season on record refuses to go out quietly: As of December 1, a low-pressure system with the potential to become Subtropical Storm Kappa was located over the northeastern Atlantic, off the coast of Portugal, with two-day odds of development of 10%.
The 2020 season was notable not only for its record number of named storms (after breaking into the Greek alphabet by the ridiculously early date of September 18), but also for its record number of rapidly intensifying storms (10); and record number of landfalling U.S. named storms (12). Let’s not forget the record-breaking November activity – two catastrophic hurricanes hit Central America in November, including Hurricane Iota, the latest category 5 storm ever recorded in the Atlantic. At least seven hurricanes from 2020 will be worthy of having their names retired: Iota, Eta, Zeta, Delta, Sally, Laura, and Isaias – although there is still no official mechanism for retiring storm names from the Greek alphabet. The record for most names retired in one season was set in 2005, when five hurricanes had their names retired.
(Check out this 76-second animation by Jake Carstens showing the National Hurricane Center (NHC) tropical weather outlooks for the entire season; 42 seconds into the video gets particularly insane, when September starts.)
An unprecedented battering of the U.S.
The U.S. suffered an extraordinary 12 landfalls by named storms in 2020, smashing the previous record of nine in 1916. Six hurricanes made a U.S. landfall, tying 2020 with 1985 and 1886 for most U.S. hurricane landfalls. Every single mile of the mainland U.S. Atlantic coast, from Texas to Maine, was under a watch or warning related to tropical cyclones at some point in 2020. Only five counties along that stretch avoided tropical storm-force winds, according to an analysis by Kyle Noel. Louisiana was hit by five named storms, the most ever to make landfall in one season in the state (old record: four in 2002).
Hurricane Laura was the strongest and most damaging landfalling U.S. hurricane of 2020, hitting southwestern Louisiana as a category 4 storm with 150 mph winds on August 27. Laura was tied as the fifth-strongest hurricane on record to make a continental U.S. landfall, and tied the Last Island Hurricane of 1856 as the strongest landfalling hurricane in Louisiana history. Incredibly, on October 9, Hurricane Delta made landfall as a category 2 hurricane with 100 mph winds just 12 miles to the east of where Laura hit. Insurance broker Aon estimates that Laura caused $16 billion in damage, and Delta $4 billion.
Aon estimates that the total U.S. damage from 2020’s hurricanes and tropical storms was $37 billion, ranking as the eighth highest total on record. Fortunately, three of the six hurricanes that hit the U.S. struck relatively sparsely populated portions of the Louisiana coast, so the 2020 damages could have been far worse. Each of the six hurricanes that hit the U.S., however, caused over $1 billion in losses, breaking the record of four billion-dollar hurricanes in a season (adjusted for inflation), set in 2004 and 2005.
Catastrophic impacts in Central America from Eta and Iota
The most catastrophic Atlantic storm of 2020 was Hurricane Eta, which made landfall in northern Nicaragua on November 3 as a category 4 storm with 140 mph winds. Moving very slowly at landfall, Eta lingered for three days over Central America and the adjacent waters, dropping catastrophic amounts of rainfall in excess of 20 inches in some regions.
Flooding from Eta’s rains killed at least 215 people and left 49 missing, primarily in Guatemala, Honduras, Mexico, and Panama, according to a preliminary tabulation released on November 12 by insurance broker Aon, making Eta the fourth-deadliest Atlantic hurricane to occur in November or December, according to statistics from NHC.
Just two weeks after Hurricane Eta’s devastating impact came Hurricane Iota, which made landfall as a category 4 storm with 155 mph winds in Nicaragua, just 15 miles from where Eta hit. There is no precedent in the Atlantic for two such powerful hurricanes to make landfall so close together in space and time. Iota brought torrential rains that inundated flooded regions still struggling to recover from Eta, with the combined tolls from the two storms exceeding 300 people dead or missing.
The combined impact of the two hurricanes on Nicaragua was estimated at $738 million – about 6% of that nation’s GDP. But the twin category 4 hurricanes left behind a truly extreme catastrophe in Honduras. As explained in a November 22 article in La Prensa, total damages from Hurricane Eta and Hurricane Iota in Honduras may exceed $10 billion – 40% of the poverty-stricken nation’s GDP. According to the Honduras Foreign Debt Forum (Fodesh), a non-governmental organization dedicated to economic affairs, the twin hurricanes will set Honduras back 22 years in economic development.
Eta and Iota severely affected more than four million people in Honduras, destroyed tens of thousands of houses, damaged or destroyed 110 bridges and 267 roads, and wiped out vast areas of productive farmland. Economic activity in northwestern Honduras’ San Pedro Sula Valley, where 60% of Honduras’s GDP comes from, was devastated. The destruction is expected to drive a large migration of destitute people from Honduras to other nations, including to the U.S.: A November 28 article in El Pais reports that the first caravans of migrants have begun to get organized.
A slew of records
The list of single-season and multi-season records established in 2020 is long. Below are the most notable ones, primarily taken from Dr. Phil Klotzbach’s 2020 season summary from November 30.
– Fifth consecutive year with above-average Atlantic hurricane activity (previous record: four years, 1998-2001).
– Fifth consecutive year with a category 5 hurricane in the Atlantic (previous record: three years, 2003-2005).
– Thirty named storms (previous record: 28 in 2005).
– Five category 4 and stronger hurricanes (tied with 2005, 1999, 1961, and 1933).
– Earliest forming ‘C’ named storm and the earliest named storm formation from the ‘E’ storm onwards.
– Ten named storms formed in September (old record: eight in 2002, 2007 and 2010).
– Five named storms formed in the Caribbean after October 1 (Gamma, Delta, Zeta, Eta and Iota), tying the record set in 2005.
– Four major hurricanes formed in the Atlantic basin after October 1 (Delta, Epsilon, Eta and Iota). Old record: two, set in numerous years.
– November produced 20 named storm days, tied with 1932 for most on record in November.
– Three Atlantic named storms formed in November (Eta, Theta and Iota). This ties 2020 with 1931, 1961, 2001 and 2005 for the most November named storm formations on record.
– Twelve Atlantic named storms made landfall in the continental U.S. (previous record: nine in 1916).
– Six Atlantic hurricanes made landfall in the continental U.S. (tied with 1886 and 1985).
– Five named storms made landfall in Louisiana (previous record: four in 2002).
– Hurricane Laura made landfall with maximum sustained winds of 150 mph in Cameron Parish, Louisiana. Laura is tied with the Last Island Hurricane of 1856 for the strongest winds for a Louisiana hurricane landfall on record.
– Hurricane Eta made landfall in Nicaragua with maximum sustained winds of 140 mph, making it the strongest November landfalling hurricane in Nicaragua on record. That record was broken just 13 days later by Iota, which hit with 155 mph winds.
– Hurricane Iota became a category 5 hurricane on November 16 – the latest Atlantic calendar year category 5 hurricane on record (previous record: November 8, by the Cuba hurricane of 1932).
– Nine named storms rapidly intensified by at least 35 mph in 24 hours in 2020: Hanna, Laura, Sally, Teddy, Delta, Epsilon, Zeta, Eta and Iota. This ties 2020 with 1995 and 2010 for the most rapidly intensifying named storms in a single Atlantic hurricane season on record. Tropical Storm Gamma also met the rapid intensification criteria by intensifying 35 mph in 24 hours, but it was a tropical depression at the start of its rapid intensification phase.
– Three named storm underwent 36-hour intensification of at least 100 mph: Delta, Eta, and Iota. According to an analysis by Sam Lillo, only eight other storms in 169 years of record-keeping accomplished this feat.
– Subtropical Storm Alpha made landfall in Portugal on September 18, becoming the first ever named storm to make landfall in the country. Alpha was also the easternmost-forming named storm on record in the Atlantic. Alpha killed one person in Spain and caused several million dollars (USD) in damages to Portugal and Spain.
– The NOAA Hurricane Hunters flew 86 missions into Atlantic named storms and disturbances, beating the previous record from 2005.
Posted on December 1, 2020 (12:33pm EST).