After briefly regaining hurricane strength on November 11, the system weakened back to a tropical storm once more, before making a fourth landfall on Florida on the next day, and proceeding to accelerate northeastward.

[3] The National Hurricane Center (NHC) began monitoring the disturbance for potential development into a tropical cyclone on October 29, as it moved across the Lesser Antilles and into the eastern Caribbean Sea.

By 18:00 UTC on that day, the system's deep convection had consolidated and a low-level circulation had become sufficiently well-defined, marking the formation of Tropical Depression Twenty-Nine centered about 105 mi (169 km) south of Pedernales, Dominican Republic.

[6] Steered westward by a low-to-mid-level ridge that extended from the subtropical Atlantic southwestward to Cuba and The Bahamas, Eta slowly organized throughout the day as a central dense overcast began to form atop its low-level center.

[7] Surrounded by an environment of low vertical shear and high sea surface temperatures, Eta began to explosively intensify on November 2.

Eta's maximum sustained winds peaked at 150 mph (240 km/h) at 00:00 UTC on November 3; at the same time, the storm had a central pressure of 929 mbar (27.4 inHg).

Even so, its maximum sustained winds remained unchanged through 06:00 UTC, during which time its minimum pressure fell to 922 mbar (27.2 inHg), with the storm reaching its peak intensity.

[3] Once inland, the hurricane rapidly weakened as it moved slowly westward over northern Nicaragua, diminishing to Category 2 intensity three hours after landfall,[12] and to a tropical storm by 12:00 UTC on November 4.

[13] Twelve hours later, around 00:00 UTC on November 5, Eta weakened to a tropical depression while its center was located about 80 mi (130 km) east of Tegucigalpa, Honduras.

[3] Despite the effects of southwesterly vertical wind shear and upper-level dry air approaching the inner core from the west,[16] the storm attained an intensity of 65 mph (105 km/h) at 00:00 UTC on November.

This movement took Eta across the southern coast of Cuba, about 30 mi (48 km) south-southeast of Sancti Spíritus, at 09:00 UTC on November 8, with winds of 65 mph (105 km/h).

[3] There, it began to re-strengthen again, and briefly gained a mid-level eye feature, as it turned sharply northwestward around the northeastern side of an upper-level low that had formed over the extreme northwestern Caribbean Sea near the Isle of Youth.

[3] Eta then turned southwestward under the influence of a strong deep-layer ridge across the Gulf of Mexico, Florida, and near the East Coast of the U.S. Its overall appearance in satellite imagery from that morning was fragmented, with inner-core convection having become shallow and broken due to dry air.

[3] The eye feature quickly dissipated, weakening Eta back to a tropical storm six hours later, when its center was located about 115 mi (185 km) south-southwest of Tarpon Springs, Florida.

[19] It then turned north-northeastward and made a final landfall near Cedar Key, Florida at 09:00 UTC on November 12, with sustained winds of 50 mph (80 km/h).

The storm further degraded and weakened over land as it accelerated northeastward, eventually emerging over the waters of the Atlantic near the Florida–Georgia border at 18:00 UTC that same day.

[24][25] Residents in coastal communities were advised to evacuate as supplies, including 88 tons of food, sleeping bags, hygiene kits, and plastic, were delivered to Puerto Cabezas according Nicaragua's National System for the Prevention, Mitigation and Attention of Disaster.

[26] The Nicaraguan Navy helped evacuate more than 3,000 families from offshore islands to Puerto Cabezas as residents in the city waited in long lines to access cash machines while getting supplies.

[27][28] Just before the storm's arrival, the Nicaraguan Army moved its Humanitarian and SAR Unit (Unidad Humanitaria y de Rescate - UHR in Spanish) to Bilwi, Puerto Cabezas, to help in search and rescue efforts that would occur due to Eta.

[39] Costa Rica's National Meteorological Institute forecast widespread rainfall in association with the outer bands of Eta, primarily along the Pacific coastline.

[44] On November 6, the Government of Cuba issued a tropical storm watch for the provinces of Camaguey, Ciego de Avila, Sancti Spiritus, Villa Clara, Cienfuegos, Matanzas, La Habana, Havana, Pinar del Rio, and the Isle of Youth.

[50] Residents of mobile homes and other vulnerable structures in the Florida Keys were told to evacuate ahead of Tropical Storm Eta as a state of emergency was declared in several counties including Monroe and Miami-Dade.

[54][55] Eta's intensity and catastrophic rainfall at the beginning of its lifetime followed by its erratic path afterwards bought widespread impacts across Central America, the Greater Antilles, and Florida.

The worst effects were felt in Cayo District, where the Macal and Mopan rivers rose more than 8.8 metres (29 ft), inundating communities from Arenal (on the border with Guatemala) to Roaring Creek.

[115] A man died in Bradenton Beach when he was electrocuted by an appliance in standing water caused by the storm and a firefighter was injured as he tried to access the home.

[121] Moisture from Eta combined with a cold front moving eastward across the Eastern United States, generating extremely heavy rainfall across Virginia and the Carolinas.

[127] The relief effort was severely hampered just two weeks later by the stronger Hurricane Iota, which made landfall approximately 15 miles (24 km) south of where Eta moved ashore.

[127] Soon after Eta made landfall, NASA's Earth Applied Sciences Disasters program began working with various regional authorities in Central America to use satellite images and data to help teams on the ground analyze the storm's impact as they rescued people in its path.

[133][134] With extensive damage across the country, Honduras's Secretary of Infrastructure and Public Services and Institute for Community Development and Water and Sanitation divided relief operations into three zones.

[136] With assistance from CONRED (Coordinadora Nacional para la Reducción de Desastres), the Government of Guatemala focused relief efforts in the departments of Izabal, Petén, and Alta Verapaz.