1983 Atlantic hurricane season

Seasonal forecasts and activity

Forecasts of hurricane activity are issued before each hurricane season by noted hurricane experts like Dr. William M. Gray, and his associates at Colorado State University. A normal season, as defined by NOAA, has six to fourteen named storms, with four to eight of those reaching hurricane strength, and one to three major hurricanes. The July 23, 1983, forecast predicted that after the slow start to the season, that a total of eight storms would form, and five of the storms would reach hurricane status. The forecast did not specify how many of the hurricanes would reach major hurricane status. However, the predictions proved to be too high, with only four named storms forming by the end of the season and three of those reaching hurricane status.

The season, which began on June 1 and ended on November 30, was very inactive because of strong upper-level wind shear. The wind shear was unusually strong throughout the Caribbean and open Atlantic, and disrupted convection in areas of disturbed weather so they could not develop. Over sixty African systems had formed and made it westward, but when they reached the Lesser Antilles, they were dissolved easily. The only area where the shear was minimal—a region encompassing the Gulf of Mexico and the Atlantic north of the Bahamas and east of Florida—was where the four named storms developed. This makes the 1983 season the least active season since the 1930 Atlantic hurricane season which had only two storms. 1983 and the prior season became the first example of two consecutive years to have no storms form in the Caribbean Sea since 1871, when reliable record began. 1983 also proved to be the first season since 1871 that a storm did not form south of 25°N latitude.

1983 was the first season for which the National Hurricane Center issued numeric landfall probabilities. Probabilities had been calculated for prior storms for use in the issuing of hurricane watches and warnings, but this was the first time the raw numeric probabilities were released to the public. The probabilities issued were accurate during Alicia, indicating that Galveston and surrounding portions of the upper Texas coast were the most likely area to be struck.

The season's activity was reflected with a low cumulative accumulated cyclone energy (ACE) rating of 17, which is classified as "below 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. Subtropical cyclones are excluded from the total.

Tropical Depression One

Tropical Depression One formed from a tropical disturbance near the Lesser Antilles on July 29. The National Hurricane Center indicated the possibility of the depression strengthening into a tropical storm in media reports but upper-level wind shear inhibited any development. The depression dissipated the next day.

Tropical Depression Two

An area of disturbed weather in the central Atlantic managed to gain enough organization to be designated Tropical Depression Two on July 31. The depression moved across the Atlantic without strengthening due to high upper-level wind shear, and dissipated near the Lesser Antilles on August 3.

Hurricane Alicia

The system that would become Hurricane Alicia originated from the western end of a frontal trough that stretched from New England to the Gulf of Mexico. Satellite pictures showed a meso-scale low pressure area that had moved off the Alabama and Mississippi coasts near the trough and was possibly the precursor system to Alicia. Pressures in the Gulf of Mexico were high and stayed high during the early development stages. On August 15, a ship recorded a minimal pressure of 1015 millibars (29.99 inHg), when the system was upgraded into Tropical Storm Alicia. With high environmental pressures around it, Alicia remained a small system.

Steering currents above Alicia remained weak during the storm's lifetime. However, a ridge was well formed to the north of the developing storms. With fluctuations in the pressures, Alicia began to drift to west on August 16. This was short-lived, as Alicia turned to the northwest towards Texas. During the period of August 16 to August 18, an anticyclone had formed over Alicia and along with slow movement over warm waters, caused Alicia to intensify rapidly. The pressure in Alicia decreased one millibar an hour in the 40 hours before landfall. Alicia peaked at 115 mph (185 km/h) in winds and 962 millibars (28.39 inHg) in pressure on August 18. Alicia made landfall near Galveston, Texas, on August 18 as a Category 3 hurricane. Alicia weakened quickly over land and accelerated over the Midwest, before dissipating over Nebraska on August 21.

As Alicia moved northward, the remnants caused moderate to heavy rainfall in several states. Houston suffered heavy damage, including thousands of shattered glass panes from downtown skyscrapers. In the end, Alicia killed 22 people and caused $2 billion (1983 US$) in damage ($4.1 billion, 2007 USD).

Hurricane Barry

Hurricane Barry originated from a tropical disturbance that left the Northwestern African coast on August 13. Most of the season, the northwestern tropical Atlantic Ocean had upper-level wind shear, which had inhibited development of systems. Due to these conditions, the disturbance was unable to strengthen until August 22 as it was approaching the Bahamas. A weak trough moved the disturbance into an area of low wind shear, and the disturbance intensified into Tropical Depression Four on the evening of August 23. The depression was just to the northeast of the northern Bahamian Islands where it strengthened into Tropical Storm Barry on the morning of August 24.

Tropical Storm Barry turned to the west and with returning wind shear, weakened into a tropical depression. The depression made landfall near Melbourne, Florida, on the morning of August 25. After Tropical Depression Barry emerged from central Florida, it was still under pressure from high-level winds. The depression entered the central Gulf of Mexico and returned to tropical storm strength. Barry rapidly intensified, becoming a hurricane on August 28, making landfall near Brownsville, Texas, that afternoon. Before landfall, Barry peaked with 80 mph (130 km/h) winds and a pressure of 986 millibars (29.11 inHg). The remnants dissipated over the northern Mexican mountains on August 29.

Hurricane Chantal

The area of disturbed weather that would soon become Chantal began in a large envelope of low pressure on the morning of September 10. The disturbed weather, nested off the coast of Bermuda, was one of the remnants of an old frontal trough that had extended from Hispaniola to the central north Atlantic Ocean. This particular area of disturbed weather become part of the northeast portion of a low-pressure system. On September 10, a reconnaissance aircraft found sustained winds of 30 mph (50 km/h) and a 1010 millibar (29.83 inHg) pressure reading. This reading indicated the system developed into the fifth tropical depression of the 1983 season.

The depression moved to within 100 miles (160 kilometers) of Bermuda and slowly intensified. Late that afternoon, Tropical Depression Five had intensified into a 40 mph (60 km/h) storm and was named Chantal. Chantal intensified rapidly, intensifying to hurricane status late on September 11. Chantal turned to the east and gained a weak outflow with cirrus clouds. The structure changed little over the next 24 hours, until becoming disorganized on the night of the 12th. Chantal was downgraded to a tropical storm around the same time.

Overnight, all convection in Chantal dissipated, and its forward speed decreased as it headed to the north. A weak wave caused Chantal to speed up and the system was absorbed in the frontal system by the night of September 14. Effects on Bermuda were minimal, with the island getting winds of up to 20 mph (25 km/h) and few thundershowers. Chantal generated swells of 30–40 ft (9–12 m) offshore.

Tropical Depression Six

Tropical Depression Six formed on September 19. The depression caused heavy rainfall in the Lesser Antilles before degenerating into a tropical wave on September 21 near the Dominican Republic.

Tropical Storm Dean

Tropical Storm Dean originated from inside a frontal cloud band, which had moved off the Eastern Coast of the United States on September 22. During the next few days, the band became stationary from The Bahamas to beyond Bermuda. During this period, a 1035 millibar (30.56 inHg) high pressure cell had become settled over the northeastern United States. This resulted in a strong pressure gradient and winds near gale force along the eastern coast.

A low-level circulation formed from the frontal cloud band on September 26 about 460  miles (740 km) east of central Florida. Dean was first identified on the afternoon of September 26 as a subtropical storm. An Air Force reconnaissance flight was sent to Dean on September 27 and only reported winds of 35 mph (55 km/h) at 23 miles (37 kilometres) from the center. A pressure of 999 millibars (29.50 inHg) indicated that Dean was strengthening as it headed northward. Additionally, satellite pictures showed that the subtropical cyclone was emerging from the cloud. This data also showed that the storm was gaining tropical characteristics and was given the name Dean on the afternoon of September 27.

Dean's winds peaked at 55 mph (80 km/h) on September 28 as it headed northward. Dean's circulation turned to the northwest on September 29 then made landfall in the Delmarva Peninsula and dissipated over land on September 30. Gale warnings were from North Carolina to Rhode Island in association with Dean. Dean produced rainfall spreading from the North Carolina/Virginia border all the way to New England. Virginia reported rains of 1 inch (25.4 mm) with 3 inches (76.2 mm) at the border. Rains peaked at 4.62 inches (117 mm) at Cockaponset Ranger Station in Connecticut. Damage was limited to minor beach erosion and flooding along the portion of Mid-Atlantic coast states.

Storm names

The following names were used for named storms that formed in the North Atlantic in 1983. The names not retired from this list were used again in the 1989 season. It was the first time these names had been used since the post-1978 change in the National Hurricane Center's naming policy.

Retirement

The World Meteorological Organization retired one name in the spring of 1984: Alicia. It was replaced in the 1989 season by Allison.