Storms of 1979

Bob | Claudette | David | Frederic | Subtrop 1

A depression formed in the southwest Gulf of Mexico on July 9, 1979, and began moving northeastward. The depression was reportedly developing into a tropical storm while centered 740 kilometres south of the Louisiana coast on the morning of the 10^th. Bob was upgraded to a hurricane later that same day. Bob had become the first July hurricane in the Gulf of Mexico since 1959. Bob turned more to the north and accelerated as it crossed the Louisiana coast near Grand Isle on July 11. After moving inland, the centre passed just west of New Orleans later that morning. Hurricane Bob weakened rapidly after crossing Lake Pontchartrain. The remnants of Bob brought heavy rainfall to southern Indiana, causing significant flooding.

There was one death in Louisiana and more then $20 million in estimated damages associated with Hurricane Bob.

Claudette was a tropical storm for two brief periods separated by a 5-day interval during which it weakened to a disorganized tropical wave. Claudette left the African coast as the strongest wave of the year.

On July 16, 1979, a surface circulation first became evident about 830 kilometres east of the Leeward Islands. The following morning, the depression was upgraded to Tropical Storm Claudette. Strong upper level westerly winds caused Claudette to weaken to a depression over Puerto Rico and to a tropical wave over Hispaniola. There was one death by drowning in Puerto Rico and damage was estimated at $750,000 because of river floods.

Phase two of Tropical Storm Claudette began as the tropical wave remnants moved into the southeastern Gulf of Mexico on the morning of July 21. A depression formed later that day, and reached tropical storm strength during the morning of the 23^rd. The centre crossed the coast near the Texas-Louisiana border on July 24. It was expected to continue northward and spread heavy rains through the lower Mississippi Valley. However, the development of a small high-pressure system aloft to the north of the centre blocked the northward movement of Claudette, and caused it to turn slowly to the west, describing a tight loop over extreme southeast Texas during the next 24 hours before finally moving to the north.

There was one death in Texas by drowning. The damage from the flooding produced by Claudette’s heavy rains is estimated at $400 million.

David was a typical Cape Verde-type hurricane. The Atlantic subtropical ridge extended westward to the vicinity of the United Stated east coast during most of David’s history, causing David to move steadily across the Atlantic and into the Caribbean Sea. Intensification also proceeded at a steady pace from the depression, which developed 2400 kilometres east of the Lesser Antilles on August 25, to a severe hurricane, centered south of Puerto Rico.

David took the first of two significant jogs in its track while centered just south of the eastern tip of the Dominican Republic. A sudden turn to the north-northwest brought the centre inland just west of Santo Domingo on August 31, causing the full effects of the hurricane to lash that city. The hurricane turned toward the west and weakened briefly to tropical storm strength while crossing Hispaniola, and emerged over the water near the northwest tip of Haiti.

The second significant jog occurred as the re-strengthening David approached the southeast Florida coast on a northwesterly course. As the centre crossed Andros Island in the western Bahamas, it appeared to be heading toward the Miami area, but a turn to the north-northwest brought a landfall just north of Palm Beach.

After moving back over the water north of Cape Canaveral, David moved inland again near Savannah, Georgia, with little change in intensity from its earlier landfall. Even though the centre of David stayed inland after moving into Georgia, it remained close enough to the coast to produce gale force winds well out to sea along the Atlantic seaboard. The storm weakened only slowly before losing tropical characteristics over New York State and the extratropical low continued to bring strong winds all the way to the Canadian Maritime Provinces.

On August 29, 1979, a tropical depression had formed from a tropical wave off the west African coast. The depression gradually strengthened while moving westward and reached tropical storm strength on August 30^th. When an eye became visible on September 1^st, Frederic was upgraded to a hurricane.

About this time, the outflow from Hurricane David began to spread over Frederic and the newborn hurricane weakened, once again, to a tropical storm on the 2^nd. Frederic gradually turned more toward the west and decelerated. Frederic passed over Puerto Rico and the Dominican Republic and then suddenly changed course toward the northwest during the afternoon of the 5^th, passing just west of Santo Domingo on the 6^th. The weakening trend continued until winds finally dropped below storm strength while Frederic was centered just north of Haiti on September 6^th. Frederic continued slowly westward over or just to the south of the Cuban coast for the next three days. Frederic proceeded to strengthen beginning about midday on the 7^th, and regained tropical storm strength, while located 160 kilometres east of the Isle of Pines, Cuba on the 9^th of September. Frederic turned toward the northwest during the next 48 hours, and regained hurricane intensity over the western end of Cuba on the 10^th.

Frederic moved steadily northwest and turned to the north-northwest with a slow increase in forward speed for the next 60 hours, the eye passing across Dauphin Island, Alabama on September 13 and the coastline near the Mississippi-Alabama border about an hour later on the same day.

Frederic turned north and northeast and increased its forward speed during the next 24 hours, losing hurricane intensity near Meridian, Mississippi on the 13^th, and becoming part of a frontal low-pressure area near the south-west corner of Pennsylvania on the 14^th. The extratropical remnants of Frederic moved very rapidly northeastward through Pennsylvania, New York and western New England during the day, and exited from northern Maine that evening.

A frontal wave formed 320 kilometres south-southwest of Bermuda on October 23. A rather classical development of a subtropical storm began during the afternoon of the 23^rd as the low moved toward the north-northeast and gradually accelerated. The storm accelerated during the afternoon of the 24^th while continuing toward the north-northeast, passing through the North Atlantic shipping lanes south of Nova Scotia.

The storm began to lose its tropical characteristics after crossing the Gulf Stream, becoming extratropical as it approached Newfoundland, and merged with a larger extratropical low moving eastward over eastern Canada.

The lowest pressure was estimated to be 980 millibars near Sable Island and the maximum sustained wind was 120 kilometres per hour (65 knots). No effects on marine interests were reported.