1991 Atlantic hurricane season

1991 Atlantic hurricane season
Basin	Atlantic
Year	1991
First storm formed	May 26, 1991
Last storm dissipated	November 30, 1991
Strongest storm name	Bob
Strongest storm pressure	950
Strongest storm winds	100
Total dep	12
Fatalities	21
Damages	1500000000
Seasonal summary	Active season with notable impacts in the United States, The Bahamas, and Bermuda

1991 Atlantic hurricane season

Season summary

The 1991 Atlantic hurricane season produced multiple tropical cyclones affecting Florida, North Carolina, New England, Cuba, and The Bahamas, beginning with pre-season development near Cuba and ending with late-November dissipation near the Azores. Forecasters at the National Hurricane Center and analysis teams at the National Oceanic and Atmospheric Administration tracked cyclogenesis across the Caribbean Sea, the Gulf of Mexico, and the western North Atlantic Ocean, noting influences from the El Niño–Southern Oscillation, the Madden–Julian Oscillation, and basin-wide sea surface temperature anomalies. The season featured notable systems including Bob, which produced impacts from North Carolina through New England and prompted responses by the Federal Emergency Management Agency and state emergency agencies. Operational meteorology during the season incorporated satellite reconnaissance from the Geostationary Operational Environmental Satellite series and aircraft reconnaissance from the US Air Force Reserve and NOAA Hurricane Hunters.

Storms

Several named storms originated from easterly waves emerging off the coast of West Africa and propagated across the tropical Atlantic toward the Caribbean Sea, while other systems developed from frontal boundaries near the Southeastern United States. Early-season activity included a May formation that affected Cuba and the Florida Keys, and mid-season tropical cyclones tracked near Hispaniola, Puerto Rico, and The Bahamas. The season's most intense cyclone, Bob, followed a northwestward recurvature that brought hurricane-force winds to North Carolina before accelerating northeast and impacting Massachusetts, Rhode Island, and Maine. Other tropical storms and hurricanes of the year caused coastal flooding, erosion, and wind damage across Jamaica, Cayman Islands, and portions of the Lesser Antilles. The basin also featured a subtropical system tracked near the central Atlantic Ocean and short-lived depressions monitored by the National Hurricane Center and the Meteo-France liaison for the Azores.

Accumulated Cyclone Energy and records

Seasonal activity measured by Accumulated Cyclone Energy (ACE) reflected contributions from the long-lived hurricanes and multiple tropical storms, with ACE driven largely by the duration of Bob and a few persistent tropical storms that maintained gale-force winds across the western Atlantic Ocean. Climatological comparisons placed the season near the long-term average in terms of ACE when referenced against the datasets curated by National Oceanic and Atmospheric Administration and historical reanalysis projects coordinated by NOAA Atlantic Oceanographic and Meteorological Laboratory. Records for the year included early-season formation and an unusual late-November dissipation near the Azores, prompting retrospective analyses published in meteorological journals and summarized in annual reports by the National Hurricane Center.

Preparations and impacts

Federal, state, and local officials issued hurricane watches and warnings that prompted evacuations along barrier islands of North Carolina and coastal communities in Massachusetts and Rhode Island, with coordination between the Federal Emergency Management Agency and state emergency management offices. Bob produced storm surge, damaging winds, and torrential rainfall that led to widespread power outages, property damage, and maritime losses; insurance claims processed by firms headquartered in New York City and regional utilities documented economic impacts. Caribbean nations including Jamaica and Cuba experienced heavy rains and localized flooding from precursor disturbances, while shipping and offshore operations adjusted schedules in the Gulf of Mexico and the western Atlantic under advisories issued by the National Hurricane Center and the United States Coast Guard. Humanitarian responses involved shelters organized by the American Red Cross and state relief agencies, and Congress later considered disaster assistance legislation for affected districts.

Meteorological history and climatology

The 1991 season's genesis loci reflected the influence of easterly waves propagating from the Sahel, interactions with the subtropical ridge over the central Atlantic Ocean, and transient troughs originating near the Mid-Atlantic States that steered systems northward. Sea surface temperature anomalies in the tropical and subtropical Atlantic modulated convective organization, while upper-level shear associated with the North Atlantic Oscillation influenced storm intensification and extratropical transition. The extratropical conversion of several systems contributed to strong pressure gradients that affected the western Atlantic and produced gale conditions affecting transatlantic shipping lanes and the coastal zones of the Northeastern United States and Atlantic Canada. Post-season reanalysis by the National Hurricane Center revised track and intensity estimates using data from Hurricane Hunter sorties, scatterometer retrievals, and archived GOES imagery.

Aftermath and retirement of names

Following the season, damage assessments and fatality tallies guided decisions by the World Meteorological Organization and the National Hurricane Center regarding nomenclature for subsequent seasons; the retirement process considered the societal impacts in New England and the Caribbean. Recovery efforts led to coastal restoration projects funded through congressional appropriations and administered by agencies including the Federal Emergency Management Agency and the United States Army Corps of Engineers. Academic studies in journals produced by organizations such as the American Meteorological Society and presentations at conferences by the American Geophysical Union evaluated the season's storms to inform forecasting improvements, emergency planning, and revisions to observational strategies for future Atlantic hurricane seasons.

Category:Atlantic hurricane seasons