Hurricane Irene–Olivia

Hurricane Irene-Olivia

Category 3 major hurricane (SSHWS/NWS)
Satellite image of Hurricane Olivia near peak intensity on September 25
Formed	September 11, 1971
Dissipated	September 30, 1971
Highest winds	1-minute sustained: 115 mph (185 km/h)
Lowest pressure	948 mbar (hPa); 27.99 inHg
Fatalities	3 direct
Damage	> $1 million (1971 USD)
Areas affected	Lesser Antilles, Leeward Antilles, Central America (Nicaragua landfall), Mexico, Southwest United States
Part of the 1971 Atlantic hurricane season 1971 Pacific hurricane season

Hurricane Irene–Olivia was the first actively tracked tropical cyclone to move into the eastern Pacific Ocean from the Atlantic basin. It originated as a tropical depression on September 11, 1971, in the tropical Atlantic. The cyclone tracked nearly due westward at a low latitude, passing through the southern Windward Islands and later over northern South America. In the southwest Caribbean Sea, it intensified to a tropical storm and later a hurricane. Irene made landfall on southeastern Nicaragua on September 19, and maintained its circulation as it crossed the low-lying terrain of the country. Restrengthening after reaching the Pacific, Irene was renamed Hurricane Olivia, which ultimately attained peak winds of 115 mph (185 km/h). Olivia weakened significantly before moving ashore on the Baja California Peninsula on September 30; the next day it dissipated.

In the Atlantic, Irene produced moderate rainfall and winds along its path, although impact was greatest in Nicaragua where it moved ashore as a hurricane. A total of 96 homes were destroyed, and 1,200 people were left homeless. The rainfall resulted in widespread flooding, killing three people in Rivas. In neighboring Costa Rica, Hurricane Irene caused more than $1 million (USD) in damage to the banana crop. Later, the remnants of Hurricane Olivia produced rainfall in the southwest United States. Flooding was reported near Yuma, Arizona, which closed a major highway, and the moisture produced snowfall in higher elevations in the Rocky Mountains.

The origins of the hurricane were from a tropical wave that exited the west African coast on September 7. It moved rapidly westward, developing into a tropical depression on September 11 about 800 miles (1300 km) east of the Windward Islands. It was one of seven active tropical cyclones in the Atlantic basin that day, one of the most active single days on record. It existed at a fairly low latitude and failed to intensify due to the unfavorable combination of Hurricane Ginger and a long trough to its northwest. On September 13, the depression passed just south of Barbados and subsequently entered the Caribbean Sea. Interacting with the terrain of South America, the center became broad and ill-defined, although Curaçao reported winds of near tropical storm force as it crossed the island on September 16. It later moved near or over northern Venezuela and Colombia. As it approached the western Caribbean, the depression was able to organize more, with less influence from landmass or the trough to its north. At 0000 UTC on September 17, it is estimated the depression attained tropical storm status; that day, it was named Irene about 350 miles (560 km) east of San Andrés. Initially, the storm was expected to track west-northwestward toward the northwest Caribbean, similar to the track taken by the destructive Hurricane Edith two weeks prior.