The 1992 Atlantic hurricane season was a significantly below average season for overall tropical or subtropical cyclones as only ten formed; however, it became one of the most destructive hurricane seasons ever recorded at the time, mostly due to Hurricane Andrew. Six of them became named tropical storms, and four of those became hurricanes; one hurricane became a major hurricane (Category 3 to 5 strength on the Saffir–Simpson scale). The season was, however, near-average in terms of accumulated cyclone energy. The season officially started on June 1 and officially ended on November 30. However, tropical cyclogenesis is possible at any time of the year, as demonstrated by formation in April of an unnamed subtropical storm in the central Atlantic.
In June, Tropical Depression One caused flooding in Cuba and in Florida, where two people were killed. In August, Hurricane Andrew, the season's only major hurricane, struck the Bahamas, Florida, and Louisiana. It was the costliest Atlantic hurricane on record at the time, caused $27.3 billion (1992 USD) in damage; it also caused as 65 fatalities. Its greatest impact was in South Florida, where the storm made landfall with 1-minute sustained winds of .
One month later, Hurricanes Bonnie and Charley produced tropical storm-force winds in the Azores, and the former caused one fatality. Tropical Storm Danielle was one of few tropical cyclones known to make landfall on the Delmarva Peninsula. The storm caused minor damage and two fatalities in the Mid-Atlantic and New England regions of the United States. One other hurricane in the season, Frances, did not significantly affect land. It developed in the central Atlantic, and tracked well away from land, and brought only light rainfall to Newfoundland. Collectively, the storms in the 1992 Atlantic hurricane season caused $27.3 billion in losses and 73 fatalities.
Seasonal forecasts +Predictions of tropical activity in the 1992 seasonSourceDateNamedstormsHurricanesMajorhurricanesRefRecord high activity 30 15 7 (Tie) Record low activity 1 0 (tie) 0 CSU December 1991 8 4 1 WRC Early 1992 6 3 N/A CSU April 1992 8 4 1 CSU June 1992 8 4 1 CSU August 1992 8 4 1 Actual activity 7 4 1 Forecasts of hurricane activity are issued before each hurricane season by Dr. William M. Gray and his associates at Colorado State University (CSU) and the Weather Research Center (WRC). A normal season as defined by the National Oceanic and Atmospheric Administration (NOAA) has 12.1 named storms, of which 6.4 reach hurricane strength, and 2.7 become major hurricanes. In December 1991, CSU issued its first forecast for the year and predicted that 1992 would see eight named storms, four hurricanes, and one major hurricane. CSU also issued a forecast in April, June and August; however, no revisions were made to the numbers of named storms, hurricanes, and major hurricane predicted in 1992. Prior to the season starting, the WRC predicted that the season would see six named storms, with three of those becoming a hurricane while no forecast was made on the numbers of major hurricanes.
Season summary
The Atlantic hurricane season officially began on June 1, but activity in 1992 began more than a month earlier with the formation of Subtropical Storm One on April 21. It was a below average season in which 10 tropical or subtropical depressions formed. Seven of the depressions attained tropical storm status, and four of these attained hurricane status. In addition, one tropical cyclone eventually attained major hurricane status, which is below the 1981–2010 average of 2.7 per season. The low amount of activity is partially attributed to weaker than normal tropical waves, the source for most North Atlantic tropical cyclones. Only two hurricanes and one tropical storm made landfall during the season. However, damage from Hurricane Andrew was exorbitant, causing most of the season's 73 deaths and $27.3 billion (1992 USD) damage toll.
Tropical cyclogenesis in the 1992 Atlantic hurricane season began with the development of Subtropical Storm One on April 21. However, over the next three months, minimal activity occurred, with only two depressions developing, one in June and the other in July. Although wind shear was relatively weak in August, only one tropical cyclone occurred in that month. However, that one tropical cyclone, Hurricane Andrew, was the strongest and costliest of the season. Though September is the climatological peak of hurricane season, an increase in wind shear prevented tropical cyclogenesis in the first half of the month. After September 16, however, five tropical cyclones developed in a span of nine days, from September 17 to 26. Thereafter, activity abruptly halted, and only one tropical cyclone developed in October, Hurricane Frances. By October 27, Frances became extratropical, ending season activity.
The season's activity was reflected with an accumulated cyclone energy (ACE) rating of 76, 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. It is only calculated for full advisories on tropical systems at or exceeding 39 mph (63 km/h), which is the threshold for tropical storm strength.
Systems
Subtropical Storm One
On April 21, a low-pressure area separated from the prevailing westerlies about southeast of Bermuda, and developed into a subtropical depression at 1200 UTC. The system maintained a large comma-shaped cloud pattern around the low-level circulation. Operationally, it was not classified until 27 hours later. Isolated from strong steering currents, the depression tracked northwestward at , and intensified into a subtropical storm early on April 22. It gradually became better organized, with a large convective band in the eastern semicircle. Reports from a nearby ship indicated peak winds of , with swells of .
The National Hurricane Center remarked the potential for the system transitioning into a tropical cyclone. An approaching trough caused the storm to stall and weaken the deep convection. On April 23, the cyclone weakened to depression status due to strong wind shear. A hurricane hunter's flight into the system confirmed the weakening, and also reported a 1.8 °F (1 °C) temperature rise in the center, suggesting a warm core and some tropical characteristics. Early on April 24, the subtropical depression turned eastward, maintaining limited convection. At the time, forecasters anticipated the depression would continue east-northeastward and become an extratropical cyclone. By late on April 24, the system was too weak to classify using the Dvorak technique, and the NHC ceased issuing advisories. Within 24 hours, the circulation dissipated as the system continued eastward through the westerlies.
Tropical Depression One
A tropical wave emerged off the western coast of Africa on June 12, and eventually developed into Tropical Depression One in the southeastern Gulf of Mexico. Operationally, the National Hurricane Center designated this system as Tropical Depression Two, which led to confusion because of Subtropical Storm One in April, and then another Tropical Depression Two in July. Outflow from Hurricane Celia in the Pacific Ocean and a trough in the Gulf of Mexico generated wind shear on the depression, which prevented it from intensifying into a tropical storm. The depression curved north-northeastward and eventually made landfall near Tampa, Florida, on June 26 around 1500 UTC. As it was moving ashore, the National Hurricane Center noted that the depression was too poorly organized to locate the center of circulation, and discontinued advisories on the system.
The depression dropped heavy rainfall in Cuba, peaking at . Large amounts of precipitation resulted in flooding, which damaged or destroyed hundreds of homes and caused two fatalities in provinces of Pinar del Río and La Habana. As the system was only a tropical depression, light winds were reported; however, a peak gust of was reported at MacDill Air Force Base. Heavy rainfall fell on the west coast of Florida, with local amounts exceeded . Precipitation throughout the state peaked at in Arcadia Tower. Heavy rainfall caused flooding in portions of Florida, which in turn, destroyed 70 houses. In addition, five homes destroyed and twelve were damaged by a tornado spawned in Nokomis. Severe crop damage to orange trees was also reported. The depression caused two fatalities in Florida and damage totaled to $2.6 million (1992 USD).
Tropical Depression Two
A squall line which moved offshore New York and southern New England formed a mesoscale convective vortex, which fired new thunderstorm activity each day as it moved within the westerlies across the northern Atlantic. Once it reached mid-ocean, an increasingly northerly steering flow dropped the system down into the subtropics to the east of Bermuda, and it maintained decent organization. By 2100 UTC on July 24, the National Hurricane Center began classifying the system as Tropical Depression Two. In the first advisory on the depression, it was noted that the previous tropical depression was erroneously classified as Tropical Depression Two.
Due to northeasterly wind shear, the depression failed to intensified or organize further, as predicted. Instead, the depression weakened by late on July 25, with satellite imagery indicating that much of the deep convection was removed from the surface circulation. By July 26, the National Hurricane Center issued its final advisory, noting that it was "too weak to classify and is rapidly losing its identity". The depression dissipated about three hours later.
Hurricane Andrew
A tropical wave moved off the coast of Africa on August 14, and organized into Tropical Depression Three on August 16 while located about halfway between the Windward Islands and the coast of Africa. It moved to the west-northwest, and strengthened into Tropical Storm Andrew on August 17. After reaching winds of , strong southwesterly shear weakened the storm, and by August 20 it weakened to a minimal storm with a pressure of . It bypassed the Lesser Antilles completely, and turned to the west in response to a building high pressure system to the north. Upon turning to the west, a trough of low pressure positioned to the southwest of Andrew created an environment with little vertical shear and well-defined outflow. The storm quickly intensified due to its small size, and became a hurricane on August 22. Andrew rapidly intensified under ideal conditions for development, and on August 23 the hurricane peaked with winds of . It crossed the Bahamas at that intensity, weakened slightly, and re-intensified to a Category 5 hurricane before making landfall near Homestead, Florida. It weakened slightly over the state to a hurricane, but restrengthened to a hurricane over the Gulf of Mexico. A strong mid-latitude trough turned Andrew northward, where it greatly weakened before hitting west of Morgan City, Louisiana on August 26 as a Category 3 hurricane. It turned northeastward, and lost its tropical identity over Tennessee on August 28, before merging with the remnants of Hurricane Lester and another frontal system over Pennsylvania on August 29.