Hurricane Iota

On October 30, a low-latitude tropical wave exited the coast of West Africa over the Atlantic Ocean. Disorganized convection east of the wave axis accompanied the wave as it moved west over open waters. During November 7–8, the wave turned northwest and traversed northern South America, crossing Guyana, Venezuela, and the Windward Islands before emerging over the Caribbean Sea. Largely favorable environmental conditions ahead of the disturbance led to the National Hurricane Center (NHC) issuing outlooks for potential cyclogenesis at this time. Turning back to the west and slowing, interaction with an upper-level trough fostered the development and expansion of convection. Strong wind shear inhibited organization as the system approached Hispaniola on November 10–11; however, the system made an unusual turn southwest in response to a mid-level ridge over the southwestern Atlantic and a surface low developed by 12:00 UTC on November 12. Lessening wind shear in this region enabled convection to concentrate around the center of the low and the system became a tropical depression on November 13, the record-tying thirty-first of the season, approximately northwest of Aruba. The depression strengthened into Tropical Storm Iota six hours later, bolstering the already record-breaking number of named storms during the 2020 season to 30. Large-scale environmental conditions consisting of sea surface temperatures of and ample low- to mid-level moisture favored significant intensification of the cyclone. As Iota moved farther from land on November 14, banding features became more pronounced and deep convection blossomed over a tightening circulation. With Iota becoming more compact and organized within the aforementioned favorable conditions and shear relaxing, the system underwent an exceptional period of explosive intensification from 18:00 UTC on November 14 to 12:00 UTC on November 16. The environment surrounding Iota was ideal for this to occur: wind shear fell below , lower- to mid-level relative humidity values exceeded 70 percent, and sea surface temperatures averaged . A symmetrical central dense overcast with temperatures averaging and broad outflow developed on November 15. Data from the 53rd Weather Reconnaissance Squadron revealed Iota to have become a hurricane by 06:00 UTC that day, Iota's core wobbled northwest at the onset of this intensification as the overall trajectory shifted west in response to a strengthening ridge spanning from the western Atlantic to the Gulf of Mexico. The most rapid phase of intensification occurred early on November 16, during which recorded a six-hour pressure drop of , including a drop of in a single hour, was observed by aircraft reconnaissance. The eye featured six mesovortices, and reached Category 4 intensity by 06:00 UTC. Around 10:45 UTC, the center of Iota passed less than north of Providencia and Santa Catalina and its eyewall struck the islands directly. It was estimated that the islands experienced sustained winds of at least . as well the second-most intense hurricane at Category 4 strength in terms of pressure, behind Hurricane Opal's 916 mbar. Iota's intensification was one of the fastest on record in the Atlantic basin. During a 42-hour period from 18:00 UTC on November 14 to 12:00 UTC on November 16, its central pressure fell by and its maximum sustained winds rose by . The pressure drop in this time span was the fourth-greatest on record, only behind Rita (), Wilma () in 2005, and Milton in 2024 (). After reaching its peak strength on November 16, Iota slowly weakened on approach to Nicaragua. Lower sea surface temperatures and ocean heat content, likely the result of upwelling from Hurricane Eta, caused convection to diminish and its eye structure to deteriorate. In the hours leading up to the hurricane's landfall on November 17, there were no reconnaissance missions and Iota's intensity was uncertain. Furthermore, land-based measurements were nearly non-existent given the devastation wrought by Eta. An unofficial gust of was reported in southern Bilwi two hours prior to landfall while the highest reliable observations at Puerto Cabezas Airport had sustained winds of and peak gusts of . Based on calculations using the SHIPS inland decay model, Iota was estimated to have weakened into a tropical storm by 18:00 UTC near the Nicaragua–Honduras border. By the start of November 18, the remaining deep convection was confined to a rainband well to the northwest of the storm's core. Scatterometer data indicate the system continued producing tropical storm-force winds off the northern coast of Honduras throughout the morning. After weakening to a tropical depression by 12:00 UTC, the surface circulation of Iota dissipated over east-central El Salvador several hours later; The system was last noted the following day well to the southwest of Guatemala. Peak intensity analysis Operationally, Iota was classified as a Category 5 hurricane with maximum sustained winds of based on stepped-frequency microwave radiometer (SFMR) measurements of and aircraft flight-level winds of . This would have made it the latest such storm during a calendar year on record in the basin and the only Category 5 hurricane of the season. However, after post-season analysis, the NHC determined the SFMR values to have a high bias as the highest observations were coupled with lower flight-level winds, a problem that had recently been discovered with other intense hurricanes. The peak SFMR value was co-located with flight-level winds of , which would typically reduce to at the surface using flight-level to surface reductions. NHC meteorologists determined that breaking waves along the west side of Providencia and Santa Catalina interfered with the instrument's measurement quality. Accordingly, the peak intensity was revised downward to , downgrading Iota to a Category 4 hurricane; however, this was within the normal range of uncertainty. Meteorologists noted that research into these errors was ongoing and the peak intensity of Iota could be revised in future analyses. == Preparations ==

Tropical storm warnings were first issued for the Colombian islands of San Andrés and Providencia around midday on November 14. Three hours later, a hurricane watch was issued for Providencia, as well as along the coast of Northern Nicaragua and Eastern Honduras, with a tropical storm watch also issued for Central Honduras. All of the watches were eventually upgraded to warnings, with an additional hurricane watch for San Andrés as well as a tropical storm warning for south central Nicaragua. The rest of the coastline of Honduras, as well as the Bay Islands, were later put under tropical storm warnings on November 16. Oxfam had to temporarily suspend operations across Nicaragua, Honduras, Guatemala, and El Salvador related to Hurricane Eta to protect relief works. Nicaragua With Nicaragua still reeling from Hurricane Eta two weeks prior, many areas remained flooded. Towns around Puerto Cabezas in particular were devastated by Eta and debris remained strewn across the area. The International Federation of Red Cross and Red Crescent Societies emphasized the risk of widespread flooding and landslides as soils were completely saturated. Some residents feared starvation while residing in shelters as Eta largely destroyed the region's crops. Honduras Approximately 80,000 people were evacuated from flood-prone areas. El Salvador The Government of El Salvador opened 1,000 shelters with a capacity for 30,000 people. By November 17 700 people had relocated from their homes. ==Impact==

Total damage from the storm was estimated at US$1.4 billion. Some flooding occurred in the state of Miranda. Colombia Mainland , the capital city of Colombia Heavy rains associated with a tropical wave and Iota caused extensive damage in Colombia. The worst damage took place in the Mohán sector of Dabeiba where landslides killed three people, injured 20, and left eight others missing. Eight people were rescued from the rubble. An estimated 70 percent of Cartagena saw flooding due to the direct effects of Iota, affecting an estimated 155,000 people. Numerous homes were damaged or destroyed by floods and landslides. City officials converted the Coliseo de Combate into a shelter capable of accommodating 200 people. Providencia and San Andrés On November 15–16, Iota passed close to the outlying Archipelago of San Andrés, Providencia and Santa Catalina as a high-end Category 4 hurricane. An estimated 98–99% of structures on the island were damaged or destroyed. Every home on the island suffered damage, with 80 percent being destroyed. Although debris covered runways at El Embrujo Airport, initially preventing aircraft from arriving or leaving, On San Andrés, torrential rains and large swells caused extensive flooding. Seawater rose up to . Powerful winds uprooted numerous trees, some of which fell on homes, and several homes lost their roof. Communications with San Andrés were temporarily lost during the storm and approximately 60 percent of the island lost power. Flooding reached a depth of at Gustavo Rojas Pinilla International Airport, preventing usage of the runways. Central America Nicaragua Nearly 44,000 homes suffered total or partial damage in Nicaragua, said Nicaraguan Finance Minister Iván Acosta, who estimated that the storms have cost the country US$743 million in losses, according to the government media site El 19. , Nicaragua Iota made landfall in Nicaragua as a mid-end Category 4 hurricane near the town of Haulover, just south of Puerto Cabezas, on November 16, only south of where Hurricane Eta made landfall 13 days prior. As Iota was moving ashore, Puerto Cabezas airport reported sustained winds of with gusts to at 02:53 UTC on November 17. Damage reports, however, were extremely limited due to damage the area sustained previously from Hurricane Eta. These reports were also limited due to most communications to Puerto Cabezas being knocked out during the storm. An amateur radio from the Club de Radio-Experimentadores de Nicaragua (CREN) reported winds of and damaged roofs, although it was unclear whether these were sustained winds or wind gusts. The roof was torn off of a makeshift hospital that was serving as a replacement to an older hospital, requiring an evacuation of the patients there. A total of 160,233 homes lost power in Nicaragua and 47,638 families lost water service. The Instituto Nicaragüense de Telecomunicaciones y Correos|es reported loss of telephone service to 35 communities. Torrential rains on already saturated soils led to extensive flooding and landslides. A storm surge of at least occurred near the town of Haulover and further north near the community of Wawa Bar. At least 28 people died in relation to the hurricane while 29 others went missing. On November 23, a passenger truck plunged off a road in a mountainous area that had been devastated by Iota, an accident which caused 17 fatalities and 25 injuries. Total damage was estimated at 12.3 billion córdobas (US$352.5 million). Iota produced heavy rainfall over portions of Honduras, causing a river to overflow in Tocoa. Mudslides and uprooted trees were also reported in portions of the country. La Ceiba, Honduras reported gusts of . At least 16 people have died and one other have gone missing as a result of impacts from Iota in Honduras. Teonela Paisano Wood, the mayor of Brus Laguna, stated concerns that continued rainfall pose a large threat to the town. Various concrete and wooden houses were reduced to rubble. As of the morning of November 18, COPECO reported 366,123 people were directly affected by the hurricane; Elsewhere Officials in Panama said one person was killed in Nole Duima in the Ngäbe-Buglé Comarca. Another person was missing in Soloy, also in the region. In Mexico, the states of Chiapas, Tabasco, and Veracruz all experienced effects from Iota's rainfall. Cumulative total across the three states were nearly 297,000 affected people, as well as almost 59,000 homes being damaged. Blocked roads cut off access to 135 communities. ==Aftermath==

The spread of disease, ranging from colds and skin rashes to gastrointestinal problems, became much more common. Other illnesses, such as dengue fever and COVID-19, had increased infection rates as well. Some refugees refused to be tested for COVID due to fears of being refused shelter due to infection. People in need of medication faced shortages and were often not able to acquire them. Colombia Following restoration of communication with Providencia on November 16, President Duque pledged immediate aid to the island. The relative lack of casualties in Providencia was attributed to residents adhering to warnings and seeking refuge in sturdy structures or interior bathrooms. On November 18, the Government of Colombia pledged 500 billion pesos (US$136 million) for recovery efforts in Bolívar and Cartagena. Nicaragua Nicaragua's power company, Enatrel, dispatched more than 100 crews to the Caribbean Coast to restore electricity. By November 17, nearly half of the outages were restored. Nicaragua's army had sent 100 rescuers to a site where a landslide caused damage. Downed trees blocking the road hampered the effort. About 1,000 food kits would be delivered, as well as recreational activities for sheltered children. The food kits would be available until the government was able to provide adequate food support. 1,000 hygiene kits, which include laundry soap, hand and dish soap, bleach, and toilet paper will be given. Families will also receive purified water, face masks, blankets, buckets, plastic sheets, eggs and beef (the last two for preferred protein sources). Honduras As of November 25, 2.5 million people had limited or no access to health services due to impacts. Officials have reported that more than 4 million people have been affected by Eta and Iota. Project HOPE has given shipments of Personal protective equipment, 50,000 masks, as well as items for the WASH project. Approximately 185,000 people have been displaced. Additionally, ten health facilities reported the complete loss of cold chain equipment, hampering preparations for the distribution of COVID-19 vaccines. ==Retirement==

Due to the extensive damage and loss of life brought by the hurricane in Central America, the Greek letter Iota, from the auxiliary storm name list, was retired by the World Meteorological Organization (WMO) in March 2021, and will never be used again for an Atlantic tropical cyclone. The WMO also decided to discontinue the use of the Greek alphabet auxiliary list, and replaced it with a new 21-name supplemental list for use when a regular naming list is exhausted. ==See also==