Hurricane Allen was a rare and extremely powerful Cape Verde hurricane that affected the Caribbean, eastern and northern Mexico, and southern Texas in August 1980. The first named storm and second tropical cyclone of the 1980 Atlantic hurricane season, it was the fifth most intense Atlantic hurricane on record in terms of barometric pressure, behind Hurricane Rita, the 1935 Labor Day hurricane, Hurricane Gilbert, and Hurricane Wilma. It was one of the few hurricanes to reach Category 5 status on the Saffir–Simpson Hurricane Scale on three occasions, and spent more time as a Category 5 than all but two other Atlantic hurricanes. Allen is the only hurricane in the recorded history of the Atlantic basin to achieve sustained winds of , thus making it the strongest Atlantic hurricane by wind speed. Until Hurricane Patricia in 2015, these were also the highest sustained winds in the Western Hemisphere. Hurricane Allen was also the second strongest tropical cyclone to hit the Gulf of Mexico, with the strongest being Hurricane Rita.
Throughout its life, Allen moved through the deep tropics on a westerly to northwesterly course through the tropical Atlantic Ocean, Caribbean Sea, and Gulf of Mexico before making its final landfall near the United States–Mexico border. At peak strength, it passed near Haiti, causing hundreds of deaths and heavy damage. After crossing the Gulf of Mexico, Allen weakened as it struck the lower Texas coast, causing high winds, a significant storm surge, and heavy rainfall, which caused damage to southern Texas. Overall, Allen killed at least 269 people and left $1.57 billion in damages (1980 US dollars), mostly within the United States and Haiti. Because of its impact, the name Allen was retired from the six-year revolving list of Atlantic tropical cyclone names in 1981 and the name was replaced by Andrew. The name Andrew, though, was subsequently retired after the 1992 season's Hurricane Andrew. The remnants of the storm caused a brief lapse in the heat wave of 1980 in places like Dallas/Fort Worth, Texas, which had recorded 69 days of heat.
Meteorological history
Allen was an early Cape Verde-type hurricane which originated from a tropical wave that previously moved off the African coastline on July 30. The system developed as it moved westward, becoming a tropical depression on August 1. However, the National Hurricane Center did not initiate advisories on Allen until almost 24 hours later, when it was centered east of the Windward Islands. Early on August 2, as the depression moved towards the Caribbean, it had intensified and became the first named storm of the season. The National Hurricane Center noted that conditions appeared favorable for further intensification. However, it was also noted that a large cold-low north of Puerto Rico was producing strong westerly wind shear, which would cause Allen to possibly encounter unfavorable conditions within 72 hours. Although slower forward movement was anticipated, Allen remained at generally the same westward pace, between . By August 3, the National Hurricane Center retracted predictions of less favorable conditions from the cold-low north of Puerto Rico, since that weather system was weakening and moving westward.
At 1600 UTC on August 3, the National Hurricane Center upgraded Allen to hurricane status, as an Air Force plane recorded winds of . However, in post-analysis, it was discovered that Allen had been a hurricane since 0000 UTC on August 3. Shortly after the upgrade, Allen began a period of rapid deepening, and intensified into a major hurricane at 0000 UTC August 4, while roughly northwest of Bridgetown, Barbados. Six hours later, Allen passed only south of St. Lucia at 0600 UTC. Although the National Hurricane Center noted that conditions favored slow strengthening, Allen continued to rapidly intensify, and became a Category 4 hurricane only two hours after that advisory. Later on August 4, the National Hurricane Center noted a barometric pressure of , and that it would not drop significantly within 24 hours. Shortly before 0000 UTC on August 5, the minimum pressure decreased to , which was noted as equivalent to Hurricane David in the previous season.