Hurricane Harvey was a powerful and catastrophic tropical cyclone that made landfall in Texas and Louisiana in August 2017, causing widespread flooding and more than 100 deaths. It is tied with 2005's Hurricane Katrina as the costliest tropical cyclone on record, inflicting $125 billion (2017 USD) in damage, primarily from catastrophic rainfall-triggered flooding in Greater Houston and Southeast Texas; this made the storm the costliest natural disaster recorded in Texas at the time. It was the first major hurricane to make landfall in the United States since Wilma in 2005, ending a record 12-year span. In a four-day period, many areas received more than 40 inches (1,000 mm) of rain as the system slowly meandered over eastern Texas and adjacent waters, causing unprecedented flooding. With peak accumulations of 60.58 in (1,539 mm) in Nederland, Texas, Harvey was the wettest tropical cyclone on record in the United States. The resulting floods inundated hundreds of thousands of homes, which displaced more than 30,000 people and prompted more than 17,000 rescues.
The eighth named storm, third hurricane, and first major hurricane of the extremely active 2017 Atlantic hurricane season, Harvey developed from a tropical wave to the east of the Lesser Antilles, reaching tropical storm status on August 17. The storm crossed through the Windward Islands on the following day, making landfall on the southern end of Barbados and a second landfall on Saint Vincent. Upon entering the Caribbean, Harvey began to weaken due to moderate wind shear, and degenerated into a tropical wave north of Colombia, late on August 19. The remnants were monitored for regeneration as it continued west-northwestward across the Caribbean and the Yucatán Peninsula, before redeveloping over the Bay of Campeche on August 23. Harvey then began to rapidly intensify on August 24, regaining tropical storm status and becoming a hurricane later that day.
While the storm moved generally northwest, Harvey's intensification phase stalled slightly overnight from August 24–25; however, Harvey soon resumed strengthening and quickly became a Category 4 hurricane later that day with peak 1-minute sustained winds of 130 mph. Hours later, Harvey made landfall at San José Island, Texas, at peak intensity, followed by another landfall at Holiday Beach at Category 3 intensity. Rapid weakening then ensued, and Harvey had downgraded to a tropical storm as it stalled near the coastline, dropping torrential and unprecedented amounts of rainfall over Texas. On August 28, the storm emerged back over the Gulf of Mexico, strengthening slightly before making a fifth and final landfall in Louisiana on August 29. As Harvey drifted inland, it quickly weakened again as it became an extratropical cyclone on September 1, before dissipating two days afterwards.
In addition to the huge cost and extent of the damage it caused, Harvey caused at least 107 confirmed deaths: 106 in the United States plus 1 in Guyana. Due to the extensive damage, the name Harvey was retired in April 2018 and will not be used for another Atlantic tropical cyclone.
A westward-moving tropical wave emerged from Africa over the eastern Atlantic Ocean on August 12. A surface circulation slowly developed and convection consolidated around the low over the subsequent days; the system became a tropical depression on August 17. Maintaining its brisk westward motion, the system strengthened slightly and became a tropical storm later that day, at which time it was assigned the name Harvey. With maximum sustained winds of 45 mph (70 km/h), Harvey made landfalls in Barbados and St. Vincent on August 18 before entering the Caribbean. Hostile environmental conditions, namely wind shear, imparted weakening and caused Harvey to degenerate into a tropical wave by August 19. Though it lacked an organized surface low, the remnants of Harvey continued to produce significant convection as it traversed the Caribbean Sea and Yucatán Peninsula. The system reached the Bay of Campeche in the Gulf of Mexico on August 23 and soon consolidated around a new surface low.
Late on August 23, the remnants of Harvey regenerated into a tropical cyclone and re-attained tropical storm intensity by 18:00 UTC. Initial reorganization was slow; however, within a highly favorable environment, the system soon underwent rapid intensification as an eye developed and its central pressure quickly fell. After becoming a hurricane on August 24, Harvey continued to quickly strengthen over the next day, ultimately reaching peak intensity as a Category 4 hurricane. Around 03:00 UTC on August 26, the hurricane made landfall at peak intensity on San Jose Island, just east of Rockport, with winds of 130 mph (210 km/h) and an atmospheric pressure of 937 mbar (27.7 inHg). It made a second landfall on the Texas mainland, at Rockport, three hours later in a slightly weakened state. Harvey became the first major hurricane to make landfall in the United States since Wilma in 2005.
Once Harvey moved inland, it began to weaken rapidly as its speed slowed dramatically to a crawl, and Harvey weakened to a tropical storm on August 26. For about two days the storm stalled just inland, dropping very heavy rainfall and causing catastrophic flash flooding. Harvey's center drifted back towards the southeast, ultimately re-emerging into the Gulf of Mexico on August 28. Once offshore, the poorly organized system struggled against strong wind shear. Deep convection persisted north of the cyclone's center near the Houston metropolitan area along a stationary front, resulting in several days of record-breaking rain. Early on August 30, the former hurricane made its fifth and final landfall just west of Cameron, Louisiana, with winds of 45 mph (70 km/h). Associated convection with Harvey became focused north of the center and along a warm front on September 1 as it moved further inland, indicating that the system transitioned into a post-tropical cyclone by 06:00 UTC that day. The remnants continued northeastwards before being absorbed into another extratropical system on September 3.
Tropical cyclone warnings and watches for the Windward Islands were issued starting at 15:00 UTC on August 17, about six hours before Harvey developed. At that time, a tropical storm watch was posted for Dominica, while a tropical storm warning became in effect in Barbados, Martinique, Saint Lucia, and Saint Vincent and the Grenadines. All watches and warnings were discontinued by late on August 18, as the storm continued westward into the Caribbean.
In Honduras, a green alert was issued for the Atlántida, Islas de la Bahía, Colón, Cortés, Gracias a Dios, Olancho, and Yoro departments. About 8 inches (200 mm) of precipitation was expected along the coast, while inland areas were forecast to receive 2.76 to 3.15 in (70 to 80 mm) of rain. As the remnants of Harvey approached Mexico, the Civil Protection Secretary of the state of Campeche issued a blue alert, indicating minimal danger. When Harvey redeveloped at 15:00 UTC on August 23, the Government of Mexico issued a tropical storm watch in Tamaulipas from Boca de Catan to the mouth of the Rio Grande. The watch remained in effect until 21:00 UTC on August 25, after it became evident that the storm no longer posed a significant threat to that area.
FEMA worked with the Coast Guard, Customs and Border Protection, and Immigration and Customs Enforcement to prepare for the storm and its aftermath. The agency placed disaster response teams on standby at emergency posts in Austin, Texas, and Baton Rouge, Louisiana.
Upon the NHC resuming advisories for Harvey at 15:00 UTC on August 23, a hurricane watch was issued in Texas from Port Mansfield to San Luis Pass, while a tropical storm watch was posted from Port Mansfield south to the mouth of the Rio Grande and from San Luis Pass to High Island. Additionally, a storm surge watch became in effect from Port Mansfield to High Island. Additional watches and warnings were posted in these areas at 09:00 UTC on August 24, with a hurricane warning from Port Mansfield to Matagorda; a tropical storm warning from Matagorda to High Island; a hurricane watch and tropical storm warning from Port Mansfield to the Rio Grande; a storm surge warning from Port Mansfield to San Luis Pass; and a storm surge watch from Port Mansfield to the Rio Grande. As the hurricane neared landfall on August 24, an extreme wind warning—indicating an immediate threat of 115–145 mph (185–235 km/h) winds—was issued for areas expected to be impacted by the eyewall; this included parts of Aransas, Calhoun, Nueces, Refugio, and San Patricio counties. The watches and warnings were adjusted accordingly after Harvey moved inland and began weakening, with the warning discontinued at 15:00 UTC on August 26. By 09:00 UTC on the following day, only a tropical storm warning and a storm surge warning remained in effect from Port O'Connor to Sargent. However, watches and warnings were re-issued as Harvey began to re-emerge into the Gulf of Mexico, and beginning at 15:00 UTC on August 28, a tropical storm warning was in effect for the entire Gulf Coast of Texas from High Island northward.