1971 Atlantic hurricane season

The 1971 Atlantic hurricane season was an active Atlantic hurricane season overall, producing 13 named storms (including a nameable system that went unnamed), of which 6 strengthened into hurricanes. The season officially began on June 1, 1971, and lasted until November 30, 1971. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. This season, the first storm, Arlene, developed on July 4, while the last, Laura, dissipated on November 22.

Activity was steady through most of the season. Hurricane Edith was its strongest system, reaching Category 5 on the Saffir–Simpson scale. It struck Nicaragua at peak intensity, killing dozens, and later hit southern Louisiana. Hurricane Ginger was its longest-lived system, lasting 27 days from early September to early October, setting a record for the longest known duration of a North Atlantic tropical cyclone (not surpassed until 2003). Ginger moved ashore in North Carolina, producing heavy rains and damaging winds. An unnamed storm in August attained hurricane status further north than any other Atlantic hurricane on record. On September 11–12, there were five active Atlantic tropical cyclones at one time. Despite the activity, damage in the United States totaled about $235 million (1971 USD$,  USD), which National Hurricane Center forecaster Paul Hebert noted was "pretty small considering we had five storms in a row strike the U.S." The depression tracked northeastward due to a ridge over New England, and the cyclone passed just southeast of the Outer Banks. After a Hurricane Hunters plane observed gale-force winds, the depression was upgraded to Tropical Storm Arlene late on July 5; in the post-season summary, meteorologist Neil Frank noted, "the surprising element in the development of Arlene was the rapidity of the transformation process."

Unnamed hurricane

A hybrid-type depression formed east of Bermuda on July 29. It moved rapidly southwestward before turning to a northwest drift. On August 3, it was classified as a tropical depression, and the next day the system passed near Bermuda. The depression accelerated to the northeast, strengthening into a tropical storm on August 5. It intensified further due to baroclinity, or enhanced instability through different levels of the atmosphere caused by temperature and moisture gradients. On August 6, a drilling rig about southeast of Newfoundland recorded sustained winds of with gusts to 126 mph (204 km/h) at an altitude of ; this suggested the storm attained hurricane status at 46° North, which is the northernmost location for a tropical storm to intensify into a hurricane. Halifax International Airport reported 10.49 in (266 mm) of rainfall in a 30‑hour span, which caused widespread flooding. Several bridges in the region were washed out, while railways were covered by water, forcing trains to suspend their operation. Overall monetary damage from Beth is estimated up to $5.1 million (1971 USD$,  USD).

The depression emerged into the Gulf of Mexico on August 15 near Tampa, and later turned to the northeast ahead of an upper-level low. On August 16, it intensified as it moved ashore near Cedar Key, where hurricane-force wind gusts were briefly observed. The depression dissipated on August 17 over South Carolina, although in that state it produced its heaviest rainfall, totaling in Sullivan's Island. The remnants continued northeastward through the Mid-Atlantic States and New England, crossing into Canada on August 20.

Tropical Storm Chloe

A tropical wave moved off the coast of Africa on August 13, moving westward for several days before organizing into a tropical depression on August 18 about east of Barbados. It quickly moved through the Lesser Antilles, where it produced wind gusts up to . The cyclone also dropped heavy rainfall up to on Barbados and Martinique. After entering the eastern Caribbean Sea, the depression intensified into Tropical Storm Chloe on August 20. About 18 hours after attaining tropical storm status, Chloe quickly strengthened to peak winds of about 215 mi (345 km) south of the Mona Passage, as reported by reconnaissance aircraft. On August 25, Chloe moved ashore in Belize as a weak tropical depression, and dissipated shortly thereafter without ever having caused significant damage or deaths. The remnants of Chloe later spawned Hurricane Lily in the eastern Pacific Ocean. The storm spawned a tornado near Norfolk, Virginia, damaging twelve houses and downing hundreds of trees. Tropical Storm Doria dropped heavy precipitation in New Jersey, peaking at 10.29 in (261 mm) in Little Falls. The rainfall led to record-breaking river levels and flooding in several houses, resulting in damage to dozens of houses across the state. Moderate damage and rainfall continued along its path into New England and southeastern Canada. In all, Tropical Storm Doria caused seven deaths and $147.6 million (1971 USD$,  USD).

Hurricane Edith

Hurricane Edith, the strongest storm of the season, developed from a tropical wave on September 5 to the east of the southern Lesser Antilles. It moved quickly across the southern Caribbean Sea, intensifying into a hurricane just off the north coast of South America. Edith rapidly intensified on September 9 and made landfall on Cape Gracias a Dios as a Category 5 hurricane on the Saffir-Simpson Hurricane Scale. It quickly lost intensity over Central America and after briefly entering the Gulf of Honduras it crossed the Yucatán Peninsula in Mexico. After moving across the Gulf of Mexico, a trough turned the storm to the northeast and Edith, after having restrengthened while accelerating towards the coast, made landfall on Louisiana with winds of 105 mph (170 km/h) on September 16. Edith steadily weakened over land and dissipated over Georgia on September 18. In Texas high tides caused coastal flooding but little damage. Edith caused moderate to heavy damage in portions of Louisiana due to flooding and a tornado outbreak from the storm. One tornado, rated F3 on the Fujita Scale, damaged several homes and injured multiple people in Baton Rouge. The tornado outbreak extended eastward into Florida. Damage in the United States totaled $25 million (1971 USD$,  USD). there, the hurricane produced gusty winds and high waves, but no damage.

While over the western Atlantic Ocean, Ginger became the last target of Project Stormfury, which sought to weaken hurricanes by depositing silver iodide into tropical cyclone rainbands. Ginger ultimately struck North Carolina on September 30 as a minimal hurricane, Heavy rainfall flooded towns and left heavy crop damage, with 3 million bushels of corn and 1 million bushels of soybean lost. Damage in the state was estimated at $10 million (1971 USD$,  USD). Further north, moderate rainfall and winds spread through the Mid-Atlantic states, although no significant damage was reported outside of North Carolina. The heavy rains triggered extensive flooding that caused over a dozen fatalities and left thousands of residents homeless in Pennsylvania and New Jersey. In Chester, Pennsylvania a stone dam collapsed, forcing hundreds of families to evacuate and damaging homes, businesses, roads, and bridges. Governor Milton Shapp declared a state of emergency in several Pennsylvania counties following the floods.

Hurricane Irene

A tropical wave spawned a tropical depression on September 11 about 800 mi (1300 km) east of the Windward Islands. The cyclone tracked nearly due westward at a low latitude, passing through the southern Windward Islands and later over northern South America. In the southwest Caribbean Sea, it intensified to a tropical storm and later a hurricane. Irene made landfall on southeastern Nicaragua on September 19, and maintained its circulation as it crossed the low-lying terrain of the country. Restrengthening after reaching the Pacific, Irene was renamed Hurricane Olivia, which ultimately attained peak winds of 115 mph (185 km/h) before weakening and dissipating over northwestern Mexico.

In the Atlantic, Irene produced moderate rainfall and winds along its path, although impact was greatest in Nicaragua where it moved ashore as a hurricane. and 1,200 people were left homeless. The rainfall resulted in widespread flooding, killing three people in Rivas. In neighboring Costa Rica, Hurricane Irene caused more than $1 million (1971 USD$,  USD) in damage to the banana crop. The hurricane was the first actively tracked tropical cyclone that moved into the eastern Pacific Ocean from the Atlantic Ocean.

Tropical Storm Janice

The origins of Janice were from a tropical wave that moved off the coast of Africa on September 18. It developed into a tropical depression on September 21 about 1050 mi (1700 km) west-southwest of Cape Verde, which was the easternmost formation of the named storms this season. The next day, the depression intensified into Tropical Storm Janice, and quickly reached peak winds of . The storm never became well-organized, with its peak winds located east of the broad center. Despite being in a climatologically favored region for further development, Janice weakened due to increased wind shear from Hurricane Ginger. The circulation became elongated and separated from the convection, and on September 24 the storm weakened to a tropical depression. Later that day Janice dissipated just northeast of the Lesser Antilles as it was absorbed by Ginger. Around that time, it produced rainfall in the northeastern Caribbean, reaching on Saint Kitts; no damage or fatalities were reported. As it was slowly moving off of the coast of Cuba, Laura dropped heavy rainfall, including nearly across most of the Isle of Youth. On the Isle of Youth, Laura produced winds of , with gusts to . The storm's passage was believed to have diverted a flock of great black-backed gulls toward Central America and north-coastal South America; the species is usually found in the Mid-Atlantic states, and were migrating to the Gulf Coast or Cuba when they were affected by the storm. Heavy rainfall was reported across Central America. Laura was one of only four November storms to affect Belize. On Glover's Reef offshore, the storm stranded a group of about 20 scientists affiliated with the Smithsonian Institution who required rescue. The storm damaged several buildings on the Belize mainland.

Other systems

thumb|right|300px|Tracks of all depressions during 1971

In addition to the named storms and otherwise notable cyclones, there were several weak depressions during the season. After a June devoid of activity, three tropical depressions developed within the first ten days of July. The first became Tropical Storm Arlene on July 4, and the second formed off the coast of Louisiana on July 6. Just two days later, another tropical depression formed in the northwestern Gulf of Mexico, quickly moving ashore in southern Texas before dissipating on July 11; it dropped light rainfall along its path.

In August, there were two tropical depressions, in addition to the named storms and the notable Tropical Depression Seven. The first, Tropical Depression Five, developed in the central Gulf of Mexico on August 6. It made landfall in Louisiana three days later, eventually dissipating over Mississippi. The other, designated Tropical Depression Ten, formed over the Bahamas on August 28. It moved westward, crossing Florida and the Gulf of Mexico before dissipating over southeastern Louisiana on September 1. The depression dropped moderate rainfall along the Gulf Coast, peaking at at Gulf Shores, Alabama.

There were three non-developing tropical depressions in September, the first of which just off the coast of Africa on September 3. It moved west-northwestward, passing near Cape Verde before dissipating on September 8. The next, Tropical Depression Fifteen, originated on September 8 east of Florida from the same trough that also spawned Fern, Ginger, and Heidi. It initially moved northward before curving to the west, making landfall near the Georgia-South Carolina border on September 11 before dissipating the following day. The other, Tropical Depression Sixteen, developed off the coast of Africa on September 10, moving westward before dissipating on September 14.

Storm names

The following list of names was used for named tropical storms that formed in the North Atlantic in 1971. This is the same list used in the 1967 season, with the exception of Beth, which replaced Beulah. Storms were named Beth, Kristy, and Laura for the first time in 1971. No names were retired following the season; however, an overhaul of the naming system in 1979 to include male names resulted in this list being discarded.

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Arlene
Beth
Chloe
Doria
Edith
Fern
Ginger

Heidi
Irene
Janice
Kristy
Laura

Season effects

This is a table of all of the storms that formed in the 1971 Atlantic hurricane season. It includes their name, duration, peak classification and intensities, areas affected, damage, and death totals. Deaths in parentheses are additional and indirect (an example of an indirect death would be a traffic accident), but were still related to that storm. Damage and deaths include totals while the storm was extratropical, a wave, or a low, and all of the damage figures are in 1971 USD.