The 1981 season was high in activity with eighteen tropical depressions and twelve storms forming that year. The season began early, as Tropical Storm Arlene formed on May 6. Arlene made landfall in Cuba, being absorbed by a low later. Tropical Depression Two moved out of the Gulf of Mexico into eastern Texas on June 5, producing localized rainfall amounts of 12 inches (300 mm) and numerous tornadoes over Louisiana before recurving across the Southeast United States. Tropical Storm Bret formed as a subtropical low in the open Atlantic Ocean, and made landfall in the Delmarva Peninsula.
Tropical Depression Four formed in the Gulf of Mexico on July 25, moving into Mexico the next day, and causing heavy rains in west Texas, Oklahoma, and Arkansas when its remnants moved into the United States. Tropical Storm Cindy formed on August 2 in the open Atlantic and became an extratropical cyclone on August 5. Hurricane Dennis formed on August 7 near South America. Dennis degenerated into a depression while making landfall in the Leeward Islands, but regained storm strength while over Cuba. Dennis moved near the southeast United States coastline from Florida to Virginia, briefly becoming a hurricane. Dennis weakened into a tropical storm and was declared an extratropical cyclone on August 22.
Tropical Depression Seven formed in mid-August and tracked through the Windward Islands before dissipating in the eastern Caribbean Sea. Tropical Depression Eight led to a significant flooding event between San Antonio and Houston on August 30 and August 31 while recurving through Texas into Louisiana. Hurricane Emily formed on September 1 southeast of Bermuda. Emily made a cyclonic loop as a tropical storm. Emily strengthened into a hurricane out in the North Atlantic Ocean and by September 12, was no longer identifiable. Hurricane Floyd was a Category 3 hurricane that grazed Bermuda, but no damage was reported. Hurricane Gert formed September 8, strengthened into a Category 2 hurricane, and followed the same track as Floyd, dissipating near the Azores. Hurricane Harvey became the strongest storm of the season, reaching Category 4 strength. Harvey never affected land, but ships reported tropical storm-force winds. Tropical Depression Thirteen brought gusts of tropical storm force to Bermuda in mid-to-late September. Hurricane Irene also stayed out at sea, reaching Category 3 strength and was extratropical in early October. The extratropical Irene made landfall in France.
Tropical Depression Fifteen was small and well-organized as it crossed the tropical Atlantic before weakening as it moved through the northeast Caribbean and southwest North Atlantic during late September and early October. Tropical Storm Jose was a short-lived storm forming out in the open Atlantic in late October. Jose never affected land and dissipated on November 1 near the Azores. Hurricane Katrina formed in the Caribbean Sea, and made landfall in Cuba after reaching hurricane strength. Katrina was the only named storm with fatalities. The final storm of the season, Subtropical Storm Three, formed in the Atlantic Ocean on November 12 and moved north, making landfall in Nova Scotia and becoming extratropical soon after.
The season's activity was reflected with a cumulative accumulated cyclone energy (ACE) rating of 100, which is classified as "near normal". ACE is, broadly speaking, a measure of the power of the hurricane multiplied by the length of time it existed, so storms that last a long time, as well as particularly strong hurricanes, have high ACEs. ACE is only calculated for full advisories on tropical systems at or exceeding 34 knots (39 mph, 63 km/h) or tropical storm strength. Although officially, subtropical cyclones are excluded from the total, the figure above includes periods when storms were in a subtropical phase.
Arlene was a very unusual tropical storm in 1981. It formed on May 6, well before the beginning of the normal hurricane season. It developed out of a disturbance that moved from the Pacific Ocean across Central America into the Caribbean Sea. As the disturbance tracked northeast across the western Caribbean, it became a tropical depression, then on May 7 reached tropical storm strength near the Cayman Islands. Arlene struck eastern Cuba on the night of May 7, and the passage over land weakened it to a depression. It restrengthened briefly over the southeastern Bahamas, but weakened again and was absorbed by another system. Reported damage was minimal.
A tropical depression formed in the Bay of Campeche near Veracruz, Mexico, on June 3. The system moved north-northwest, lured by a cyclone over the southern Plains. Tropical Depression Two made landfall along the upper Texas coast on June 5, spreading up to 15 inches (380 mm) of rainfall northeast of the point of landfall. A total of nine tornadoes stuck the western Gulf coast, with eight touching down in Louisiana. Three people died; two due to flooding and one from an associated tornado. The depression quickly recurved through the Mississippi Valley, and deepened as it moved off the coast of the Mid-Atlantic states into the western subtropical Atlantic on June 7. At least US$4 million in damage was caused by this depression.
Bret formed out of a subtropical low roughly 150 miles (240 km) off the coast of North Carolina. The storm moved west-northwest, striking land in southern Maryland on July 1. Bret weakened significantly just before landfall, and reported winds were below gale force. Rainfall amounts were light, with a narrow area of over one inch of rain reported near its track and within the central Appalachians. The highest rainfall amount reported was 4.48 inches (114 mm) at Big Meadows, Virginia. No significant damage was reported, but one fatality was reported at Nags Head, North Carolina due to riptides.
A tropical disturbance moved across the Caribbean sea between July 20 and July 24 before moving across the Yucatán peninsula. After emerging into the south-central Gulf of Mexico, the disturbance organized into a tropical depression early on July 25. The depression moved west-northwest into northeast Mexico on July 26 before its surface circulation dissipated. Heavy rains fell across western Texas, Oklahoma, and Arkansas when the remains of this system interacted with a stationary front across the southern Plains between July 28 and July 30.
A subtropical depression that developed along a cold front organized into Tropical Storm Cindy on August 2, in the open Atlantic midway between Bermuda and Nova Scotia. Cindy tracked east-northeast until it became extratropical on August 5 as it moved over colder water. The storm never affected land and caused no known damage.
Dennis began as Cape Verde-type hurricanes typically do. A tropical wave leaving the coast of Africa on August 5 developed into Tropical Storm Dennis on August 7 near Cape Verde. Unlike most such storms, Dennis degenerated to a tropical wave before reaching the Windward Islands on August 12. This wave crossed the Caribbean, passing over Jamaica before reaching the southwestern coast of Cuba on August 15.
Once near Cuba, the wave began rapid organization, restrengthening into a tropical storm. It crossed Cuba, then moved into southern Florida. Over Florida, steering currents weakened and the storm stalled. On August 19, Tropical Storm Dennis reemerged over water, skimming the coasts of the Carolinas before accelerating out to sea. Dennis reached hurricane strength before becoming extratropical on August 22.
Most damage associated with Dennis was from the heavy rainfall caused by its slow passage over Florida, although two tornadoes were also reported within Florida. The highest amount registered was near Homestead, Florida, where 25.56 inches (649 mm) of rain was measured. Agriculture damage in Dade County, Florida was estimated at $15 million (1981 USD). Coastal areas of the Carolinas were also affected by heavy rainfall, with spots seeing over 10 inches (250 mm), as well as minor beach erosion.
This system developed across the tropical Atlantic Ocean on August 18, moving westward through the Windward islands into the eastern Caribbean Sea before dissipating on August 21.
This tropical depression formed in the Bay of Campeche on August 26 and moved slowly northwest, moving ashore northeast Mexico on August 29 and into the United States on August 30. As an ill-defined surface low, a large thunderstorm complex formed near its center that day, unleashing heavy rainfall in a band 50 miles (80 km) wide which stretched along a path 200 miles (320 km) long from Seguin, Texas to north of Houston, Texas. The highest rainfall amount reported was from Pine Springs in Fayette County, Texas, where 21 inches (530 mm) fell in the 24‑hour period ending on the morning of August 31. Five died in the town of Shiner, Texas due to the flood. Downtown Halletsville flooded to a depth of 5 feet (1.5 m). Significant flooding occurred along the Lavaca, Guadalupe, and Colorado rivers in Texas. The cyclone spawned 14 tornadoes as well, including one at Scholes Field in Galveston, Texas which produced winds as high as 92 miles per hour (148 km/h) at 7:15 pm on August 31.
Its surface circulation remained ill-defined as it produced another round of heavy rainfall across northwest Louisiana on September 1. A large mesoscale convective system moved in from Oklahoma and northeast Texas, dissipating what was left of this tropical depression by September 2. Paid losses by the Federal Emergency Management Agency (FEMA) totaled nearly US$21 million (1981 dollars), with total damages exceeding US$26 million (1981 dollars).
On September 1, a subtropical storm became Tropical Storm Emily southwest of Bermuda. Emily moved northeast, crossing the island the next day, but measured winds were below tropical storm force. The storm continued generally northeast and strengthened into a hurricane. Hurricane Emily weakened over the north Atlantic and was no longer identifiable as a weather system by September 12. Hurricane Emily caused beach erosion across the East Coast of the United States, but no other damage was reported.
Floyd was first tracked as a tropical depression on September 3 when it organized east of the Leeward Islands. As the depression moved northwest, it caused heavy rain. The highest rainfall reported was 5.7 inches (140 mm) at Antigua. It strengthened into a tropical storm, then reached hurricane strength on September 7.
Floyd turned to the northeast, and passed just southeast of Bermuda as a weakening hurricane. As a tropical storm, Floyd moved east across the Atlantic until losing its identity on September 12.
No damages are associated with Floyd. Although Bermuda was directly affected, the island experienced the weaker half of the storm.
A tropical wave exited western Africa on September 1, gradually developing a concentrated area of convection. Early on September 7, it was estimated that Tropical Depression Eleven about 400 mi (640 km) east of the Leeward Islands, based on satellite imagery. The next day, data from the Hurricane Hunters indicated the depression intensified into Tropical Storm Gert. The newly upgraded storm passed between the islands of Dominica and Guadeloupe and continued to intensify, making landfall on southeastern Puerto Rico with winds of 60 mph (95 km/h) late September 8. After emerging into the Atlantic, Gert weakened while passing off the north coast of the Dominican Republic. It restrengthened while turning northward near the Bahamas, becoming a hurricane on September 10. Midday on September 11, Gert attained its peak intensity with winds of 105 mph (165 km/h) and a minimum pressure of 988 mbar (hPa; 29.18 inHg). The hurricane turned northeastward and weakened over cooler waters, passing about 100 mi (160 km) north of Bermuda on September 12 as a tropical storm. On September 14, Gert weakened further to tropical depression status, dissipating the next day.
While passing through the Leeward Islands, Gert dropped moderate rainfall of 5.85 inches (148.5 mm) on St. Thomas. Winds gusted to 50 mph (85 km/h) on the island. In Puerto Rico, rainfall peaked at 6.02 inches (153 mm) in the Puerto Rican municipality of Maricao. Gale warnings were issued for the Turks and Caicos Islands and later the southeastern Bahamas, and light rainfall occurred in the region, reaching 3.20 inches (81.28 mm) on the island of San Salvador. Winds were light in Bermuda.
Harvey formed in the central Atlantic, reaching hurricane strength only a few hours after first becoming a named system on September 12. From its initial position several hundred miles east of the Leeward Islands, Harvey moved northwest. Its path began curving more to the north, and was considered a threat to Bermuda until the continuing curve took Harvey away from the island. Harvey's track became more easterly, and the storm weakened and became extratropical as it approached the Azores. Harvey caused no reported damage, although several ships reported experiencing tropical storm force winds.
The thirteenth tropical depression developed 275 mi (443 km) southwest of Bermuda on September 22, and was initially expected to intensify into a tropical storm. Although it failed to further intensify, Tropical Depression Thirteen brought squalls to Bermuda with winds gusts of tropical storm force as it passed west of the island on September 23. Moving northward, the system merged with a developing extratropical cyclone south of Nova Scotia on September 24.
Irene became a named storm midway between the Windward Islands and Cape Verde on September 23, and its track mimicked that of Hurricane Harvey. The storm tracked northwest, becoming a hurricane on September 25. Its track then began curving to the east, eventually resulting in motion to the northeast.
The storm weakened and became extratropical in early October. The remaining extratropical storm moved over France on October 3.
This tropical depression formed southwest of the Cape Verde Islands on September 27, and tracked through the deep tropics before weakening as it moved over the Leeward Islands late on September 30. Heavy rains occurred at Guadeloupe as the system passed by the island. The depression then recurved to the south and east of Bermuda late on October 3.
Jose was a weak and short-lived tropical storm that formed far from land on October 29. It moved generally northeast before becoming subtropical and then dissipating on November 1 near the Azores.
A tropical depression formed on November 3 in the western Caribbean Sea about 150 miles (240 km) south of the Cayman Islands. The depression moved north, reaching tropical storm strength as it moved through the Caymans. Katrina continued to strengthen, reaching hurricane strength half a day before landfall in Cuba. A weakening Katrina moved across eastern Cuba on November 6. After emerging over water, the storm accelerated northeast through the Bahamas. Katrina's circulation fell apart, and the storm merged with a front on November 8.
Hurricane Katrina is reported to have killed two and caused widespread flood damage in Cuba's Camagüey province. Katrina was the only named storm responsible for fatalities in 1981.
A frontal low over the warm waters of the Gulf Stream organized into an subtropical storm on November 12 while 400 miles (640 km) east of Jacksonville, Florida. After moving northeastward, it turned to the northwest, threatening the northeastern United States as an intensifying subtropical storm that was gradually developing tropical characteristics. A high pressure system turned it to the northeast, and after peaking at 70 mph (110 km/h) it became extratropical near Nova Scotia on November 17. The storm produced significant beach erosion and coastal flooding.
The following names were used for named storms that formed in the north Atlantic in 1981. No names were retired, so it was used again in the 1987 season. It was the first use for all of these names since the post-1978 naming change, except for Arlene, Cindy and Irene which had been previously used in 1959, 1963, 1967, and 1971. Names that were not assigned are marked in gray.
Due to lack of major damage from the storms, the WMO did not retire any names in 1981. They were used again in 1987.