1973 Atlantic hurricane season

The 1973 Atlantic hurricane season was a below average tropical cyclone season overall. Of the 24 tropical or subtropical cyclones which developed, only 8 became named storms, and of those, only 4 became hurricanes, with 1 reaching major hurricane status (Category 3 or higher) on the newly implemented Saffir–Simpson hurricane wind scale.

The season officially began on June 1 and ended on November 30. These dates, adopted by convention, historically describe the period in each year when most tropical cyclones form in the North Atlantic. However, the formation of subtropical or tropical cyclones is possible at any time of the year, as demonstrated this season by the formation of multiple pre-season systems, none of which attained storm strength. The first named storm of the year, Hurricane Alice, did not form until July 1.

Two of the season's landfalling storms had severe impacts. In August, Hurricane Brenda struck the eastern coast of the Bay of Campeche, killing 10 people in Campeche, and causing the worst flooding there in decades. Then, early in September, Tropical Storm Delia hit the northwestern Gulf of Mexico coast, inundating parts of Texas and Louisiana with significant rainfall, which resulted in 5 fatalities and $6 million (1973 USD) in damage. The most intense cyclone of the season was Hurricane Ellen, which reached Category 3 strength during its trek over open water. Also, the season's final named storm, Tropical Storm Gilda, was meteorologically significant in that it became the first documented tropical cyclone on record to transition into a subtropical cyclone.

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Season summary

The first storm of the 1973 hurricane season, forming in mid-April, developed more than a month before the official start of the season. Several other short-lived, weak depressions formed before and during June; however, none reached storm intensity. The first named storm, Alice, formed on July 1. Tracking generally to the north, Alice also became the first hurricane of the season as well as the first known cyclone to impact Bermuda during July. Shortly after Alice dissipated over Atlantic Canada, another depression formed. By the end of July, two more non-developing depressions formed and the first subtropical cyclone, given the name Alfa, developed off the east coast of the United States. This storm was short-lived and dissipated on August 2 just offshore southern Maine. The first half August was relatively quiet, with only one depression forming. However, later in the month, the season's second hurricane, Brenda, formed in the northwestern Caribbean. Peaking just below Category 2 status on the newly introduced Saffir–Simpson hurricane scale, Brenda made the first recorded landfall in the Mexican State of Campeche. No major damage was recorded on the island, though the winds blew down a few trees and powerlines. The heavy rainfall, peaking at , ended a three-month drought in Bermuda.

Subtropical Storm Alfa

During late July, an upper-level low, with a non-tropical cold core, formed near Cape Hatteras, North Carolina and tracked southward. Gradually, the circulation lowered to the surface and developed subtropical characteristics. On July 31, the system attained gale-force winds off the Mid-Atlantic coast and was named Alfa, the first name from the list of subtropical storm names for the 1973 season. Tracking north-northeast, the system intensified very little as it paralleled the coastline. By August 1, the system weakened below subtropical storm intensity as it neared New England. The following day, Alfa dissipated just off the southern coast of Maine. with a maximum of in Saco.

Hurricane Brenda

Hurricane Brenda originated from a tropical wave that moved off the western coast of Africa on August 9; however, the initial wave quickly weakened upon entering the Atlantic Ocean. By August 13, the wave began to regenerate as it passed through the Lesser Antilles. Several days later, convection associated with the system consolidated into a central, organized mass The storm killed at least 10 people in the country. Winds on land gusted up to 112 mph (180 km/h), leading to severe wind damage. Two of the fatalities occurred in Campeche after 80% of the city was flooded. They were safely rescued several days later once the storm had dissipated. These rains led to flooding on several islands. One person was killed during the storm after being electrocuted by a downed power line on a flooded road.

Tropical Storm Delia

On August 27, a tropical wave formed over the central Caribbean and tracked towards the west-northwest. The system gradually developed organized shower and thunderstorm activity. By September 1, a tropical depression developed from the wave. By September 3, the depression had intensified into a tropical storm, receiving the name Delia, and began tracking more towards the west. A complex steering pattern began to take place later on that day, resulting in the creation of a more hostile environment for tropical cyclones in the Gulf of Mexico.

Along the coasts of Texas and Louisiana, the depression produced significant amounts of rainfall, peaking at near Freeport. Significant rainfall was also recorded in the Carolinas and Georgia, with numerous areas recording over .

Hurricane Ellen

The strongest storm of the season, Hurricane Ellen, began as a tropical wave that moved off the western coast of Africa on September 13. Shortly after peaking, Ellen transitioned into an extratropical cyclone before merging with a frontal system several hundred miles east of Newfoundland on September 23. Later that day, the subtropical depression organized into a tropical depression. Upon doing so, the NHC issued small craft advisories for coastal areas between North Carolina and St. Augustine, Florida. Tracking north-northwestward in response to a break in a subtropical ridge to the north, the depression eventually made landfall near Marineland, Florida and quickly weakened, dissipating before reaching the Gulf of Mexico.

Heavy rain fell in association with the depression in parts of Florida and Georgia. A maximum of fell in Orlando while several other areas recorded over of rain. Offshore, swells produced by the system reached , impacting several vessels in the region. In parts of coastal Georgia, high water resulted in several road closures and flooded a few homes. Police officers in Savannah reported that wave were topping the local seawall; however, no damage was reported.

Hurricane Fran (Bravo)

Hurricane Fran originated from a tropical wave associated with an area of convection north of Hispaniola on October 1. Late on October 8, the cyclone had become sufficiently organized to be classified a subtropical depression, and a day later the system was upgraded to Subtropical Storm Bravo. By October 10, Bravo had intensified substantially, as hurricane hunters recorded hurricane-force winds roughly from the center of the storm. Following this finding, the National Hurricane Center reclassified the system as Hurricane Fran, dropping its previous designation of Bravo. Additionally, the storm had developed a wide eye. Steered quickly eastward by a deep surface low in the westerlies, Fran accelerated towards the Azores Islands. and around that time, Fran attained its peak winds of . Later that day, the central pressure of Fran decreased to 978 mbar (hPa; ), the lowest recorded in relation to the hurricane. Shortly after reaching this intensity, the hurricane transitioned into an extratropical cyclone and quickly merged with a cold front off the coast of France. On October 12, a French ship encountered the storm, recording sustained winds of and an air pressure of 981 mbar (hPa; ). Ships near the English and French coastlines recorded winds up to as the extratropical remnants of Fran passed through the region. and killing six people. In Cuba, Gilda dropped over of rain, while 60 mph (95 km/h) winds were reported in the northern part of the country. In the Bahamas, Gilda caused significant crop damage from heavy rainfall and high tides. The storm's persistent strong currents and easterly winds caused moderate beach erosion on the East Coast of the United States, mostly along the Florida coast. The extratropical remnants of the storm produced hurricane-force wind gusts over parts of Atlantic Canada, peaking at 75 mph (120 km/h); however, no damage was reported. Storms were named Christine, Delia, Ellen and Fran for the first time in 1973. 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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Alice
Brenda
Christine
Delia
Ellen
Fran
Gilda

The NATO phonetic alphabet (below) was used to designates subtropical cyclones that formed in the north Atlantic in 1973.

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Alfa
Bravo

Season effects

This is a table of all of the storms that formed in the 1973 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 1973 USD.

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References

External links

HPC rainfall pages for 1973 Tropical Cyclones
Easy-to-read HURDAT (Atlantic Hurricane Database) tracks for 1851–2008