Hurricane Iota was a powerful and catastrophic late-season tropical cyclone which caused severe damage to areas of Central America already devastated by Hurricane Eta two weeks prior. The 31st and final tropical cyclone, 30th named storm, 14th hurricane, and record-tying seventh major hurricane of the record-breaking 2020 Atlantic hurricane season, Iota originated as a tropical wave that moved into the Eastern Caribbean on November 10. Over the next few days, the wave began to become better organized and by November 13, it developed into a tropical depression north of Colombia. The depression strengthened into Tropical Storm Iota six hours later. The storm was initially impacted by some wind shear, but a center relocation and relaxed shear allowed Iota to quickly strengthen into a hurricane on November 15, after which it underwent explosive intensification, peaking as a high-end Category 4 hurricane, with wind speeds of 155 mph (249 km/h). After weakening slightly, Iota made landfall in northeastern Nicaragua as a mid-range Category 4 hurricane, becoming the strongest recorded hurricane to make landfall in Nicaragua in November. Iota then rapidly weakened as it moved inland, dissipating on November 18.
Iota's precursor disturbance generated flash flooding on several Caribbean islands. Hurricane watches and warnings were first issued on November 14 in parts of Colombia, Nicaragua, and Honduras, with the latter two countries still recovering from Eta. Heavy rains associated with a tropical wave and Iota brought heavy rainfall to parts of Colombia, leading to flash flooding and mudslides. Heavy rain fell on much of Nicaragua, widening flash flooding caused by the hurricane's high storm surge. Mudslides caused extensive damage and multiple deaths. At least 67 people were killed due to Iota, including at least 28 in Nicaragua and 16 in Honduras, among other countries. As many as 41 people were reported as missing. The preliminary estimate for the damage in Nicaragua was US$564 million. Total damage estimates for the hurricane were set at US$1.4 billion.
Relief efforts soon followed, which included placing tents, opening temporary hospitals, and delivering food and water to those in need. Numerous power outages were restored in the days that followed. Donations worth hundreds of millions of United States dollars were given to affected countries. An estimated total of 5.2 million people were affected by the storm.
Hurricane Iota was a powerful and catastrophic late-season tropical cyclone which caused severe damage to areas of Central America already devastated by Hurricane Eta two weeks prior. The 31st and final tropical cyclone, 30th named storm, 14th hurricane, and record-tying seventh major hurricane of the record-breaking 2020 Atlantic hurricane season, Iota originated as a tropical wave that moved into the Eastern Caribbean on November 10. Over the next few days, the wave began to become better organized and by November 13, it developed into a tropical depression north of Colombia. The depression strengthened into Tropical Storm Iota six hours later. The storm was initially impacted by some wind shear, but a center relocation and relaxed shear allowed Iota to quickly strengthen into a hurricane on November 15, after which it underwent explosive intensification, peaking as a high-end Category 4 hurricane, with wind speeds of 155 mph (249 km/h). After weakening slightly, Iota made landfall in northeastern Nicaragua as a mid-range Category 4 hurricane, becoming the strongest recorded hurricane to make landfall in Nicaragua in November. Iota then rapidly weakened as it moved inland, dissipating on November 18.
Iota's precursor disturbance generated flash flooding on several Caribbean islands. Hurricane watches and warnings were first issued on November 14 in parts of Colombia, Nicaragua, and Honduras, with the latter two countries still recovering from Eta. Heavy rains associated with a tropical wave and Iota brought heavy rainfall to parts of Colombia, leading to flash flooding and mudslides. Heavy rain fell on much of Nicaragua, widening flash flooding caused by the hurricane's high storm surge. Mudslides caused extensive damage and multiple deaths. At least 67 people were killed due to Iota, including at least 28 in Nicaragua and 16 in Honduras, among other countries. As many as 41 people were reported as missing. The preliminary estimate for the damage in Nicaragua was US$564 million. Total damage estimates for the hurricane were set at US$1.4 billion.
Relief efforts soon followed, which included placing tents, opening temporary hospitals, and delivering food and water to those in need. Numerous power outages were restored in the days that followed. Donations worth hundreds of millions of United States dollars were given to affected countries. An estimated total of 5.2 million people were affected by the storm.
Meteorological history
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 185 mi (298 km) 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.
Throughout the day, minimal intensification occurred due to vertical wind shear as Iota remained a broad system with its surface- and mid-level circulations disjointed. Large-scale environmental conditions consisting of sea surface temperatures of 84 °F (29 °C) and ample low- to mid-level moisture favored significant intensification of the cyclone. However, unexpected localized moderate shear and Iota's proximity to Colombia kept the cyclone disorganized. 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 5 mph (8 km/h), lower- to mid-level relative humidity values exceeded 70 percent, and sea surface temperatures averaged 84–86 °F (29–30 °C). A symmetrical central dense overcast with temperatures averaging −112 °F (−80 °C) 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, the 14th such storm of the season. This was the second-highest number of hurricanes in a single season since reliable records began, just shy of the 15 in 2005. 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. A ragged eye formed throughout the latter part of November 15 as the system became co-located with an upper-level anticyclone.
The most rapid phase of intensification occurred early on November 16, during which recorded a six-hour pressure drop of 26 mbar (0.77 inHg), including a drop of 10 mbar (0.30 inHg) in a single hour, was observed by aircraft reconnaissance. The 15-mile-wide (24 km) eye featured six mesovortices, intense eyewall lightning, and hail. Though not fully understood, hypotheses at the time proposed that eyewall mesovortices can create intense hot towers with strong updrafts capable of more efficiently transporting mass out of the eye. This in turn hastens the rate of intensification. The mesovortices later degraded into a single, intense cell that remained in the southern eyewall through Iota's landfall in Nicaragua. Between 00:00 and 06:00 UTC, Iota became a major hurricane, the record-tying seventh instance of the season, and reached Category 4 intensity by 06:00 UTC. Around 10:45 UTC, the center of Iota passed less than 5 miles (8 km) 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 130 mph (210 km/h). The hurricane's exceptional intensification ended at 12:00 UTC on November 16 with it acquiring maximum sustained winds of 155 mph (250 km/h) and a minimum pressure of 917 mbar (27.08 inHg). This made Iota the second-most intense November hurricane on record, only behind the 1932 Cuba hurricane, as well the second-most intense hurricane in terms of pressure to peak at Category 4 strength, 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 80 mbar (2.36 inHg) and its maximum sustained winds rose by 105 mph (170 km/h). The pressure drop in this time span was the fourth-greatest on record, only behind Rita (93 mbar (2.75 inHg)) and Wilma (105 mbar (3.10 inHg)) in 2005 and Milton in 2024 (108 mbar (3.19 inHg)).
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. Around 03:40 UTC on November 17, Iota made landfall near the small village of Haulover, Nicaragua – approximately 25 mi (40 km) south-southwest of Bilwi – with estimated winds of 145 mph (235 km/h). This was only 14 mi (23 km) south of where Hurricane Eta made landfall at a similar intensity two weeks prior. 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 124 mph (200 km/h) was reported in southern Bilwi two hours prior to landfall while the highest reliable observations at Puerto Cabezas Airport had sustained winds of 83 mph (134 km/h) and peak gusts of 113 mph (182 km/h).
Once inland, Iota rapidly weakened over the mountainous terrain of Nicaragua and Honduras. Convection dramatically warmed, though the hurricane maintained a small core several hours after landfall. 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; however, its mid-level remnant continued west and soon connected to a monsoon trough. 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 160 mph (255 km/h) based on stepped-frequency microwave radiometer (SFMR) measurements of 165 mph (266 km/h) and aircraft flight-level winds of 169 mph (272 km/h). 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 148 mph (238 km/h), which would typically reduce to 133 mph (214 km/h) 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 155 mph (250 km/h), 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. The Government of Nicaragua opened 600 shelters and 63,000 people evacuated nationwide. Some residents feared starvation while residing in shelters as Eta largely destroyed the region's crops. The government of Taiwan donated 800 tons of rice to the areas expected to be impacted by the storm.
Honduras
Approximately 80,000 people were evacuated from flood-prone areas. An estimated 100,000 people remained isolated across Honduras in the aftermath of Hurricane Eta as Iota made landfall.
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.
Venezuela
The precursor tropical wave to Iota produced heavy rain across Venezuela's Falcón state, primarily in the Paraguaná Peninsula. In the Silva municipality, flooding affected 288 homes. Damage to homes was reported in El Cayude and El Tranquero. The community of Santa Ana lost electrical service. Civil Protection officials advised residents of possible flooding along the Matícora reservoir in Mauroa, the Barrancas river, and the Quebrada de Uca river. Some flooding occurred in the state of Miranda.