The 2017 Atlantic hurricane season was an event in the annual tropical cyclone season in the north Atlantic Ocean. This Atlantic hurricane season saw above-normal activity; it was the seventh most active season on record and the most active since 2005. The season officially began on June 1, 2017 and ended on November 30, 2017. These dates, adopted by convention, historically describe the period in each year when most tropical systems form. However, storm formation is possible at any time of the year, as demonstrated in 2017 by the formation of the season's first named storm, Tropical Storm Arlene, on April 19. The final storm of the season, Tropical Storm Rina degenerated to a remnant area of low pressure on November 9.

The 2017 season produced 17 named storms, of which 10 became hurricanes including six of which intensified into major hurricanes (Category 3, 4 or 5). Of those six, Harvey and Irma, became the first major hurricanes to make landfall on the continental United States in 12 years; a third hurricane, Nate, did so as well. September was both the most active month in the season and the most active month for Atlantic hurricanes ever recorded. Four long-lived major hurricanes—Irma, Jose, Lee and Maria—moved through the Atlantic Basin, as did the short-lived Hurricane Katia. Overall, more accumulated cyclone energy was generated during September 2017 than during the entire 2016 season. In April 2018, the World Meteorological Organization retired the names Harvey, Irma, Maria, and Nate from its rotating naming lists due to the number of deaths and amount of damage they caused, and they will not be used again for another Atlantic hurricane.

This timeline documents tropical cyclone formations, strengthening, weakening, landfalls, extratropical transitions, and dissipations during the season. It includes information that was not released throughout the season, meaning that data from post-storm reviews by the National Hurricane Center, such as a storm that was not initially warned upon, has been included.

The time stamp for each event is first stated using Coordinated Universal Time (UTC), the 24-hour clock where 00:00 = midnight UTC. The NHC uses both UTC and the time zone where the center of the tropical cyclone is currently located. The time zones utilized (east to west) prior to 2020 were: Atlantic, Eastern, and Central. In this timeline, the respective area time is included in parentheses. Additionally, figures for maximum sustained winds and position estimates are rounded to the nearest 5 units (miles, or kilometers), following National Hurricane Center practice. Direct wind observations are rounded to the nearest whole number. Atmospheric pressures are listed to the nearest millibar and nearest hundredth of an inch of mercury. __TOC__

Timeline

April

April 19 00:00 UTC (8:00 p.m. AST, April 18) at Subtropical Depression One develops from an area of low pressure about southwest of the Azores.

April 20 00:00 UTC (8:00 p.m. AST April 19) at Subtropical Depression One transitions into Tropical Depression One roughly southwest of the Azores. 06:00 UTC (2:00 a.m. AST) at Tropical Depression One intensifies into Tropical Storm Arlene approximately southwest of the Azores.

April 21 00:00 UTC (8:00 p.m. AST April 20) at Tropical Storm Arlene attains its peak intensity with maximum sustained winds of and a minimum barometric pressure of , about west of the Azores. 12:00 UTC (8:00 a.m. AST) at Tropical Storm Arlene transitions into an extratropical cyclone roughly west of the Azores, and subsequently dissipates.

May No tropical cyclones form in the Atlantic Ocean during the month of May.

June

June 1 The 2017 Atlantic hurricane season officially begins.

June 19 18:00 UTC (2:00 p.m. AST) at Tropical Storm Bret forms from a tropical wave about east-southeast of Trinidad, with a minimum barometric pressure of .

June 20 02:00 UTC (10:00 p.m. AST) at Tropical Storm Bret attains peak winds of and makes landfall in southwestern Trinidad. 09:00 UTC (5:00 a.m. AST) at Tropical Storm Bret makes landfall on the Paria Peninsula of Venezuela, with winds of , and rapidly degenerates into a remnant low, which later dissipates. 18:00 UTC (1:00 p.m. CDT) at Tropical Storm Cindy forms from a tropical wave about south-southwest of the mouth of the Mississippi River.

June 21 00:00 UTC (7:00 p.m. CDT, June 20) at Tropical Storm Cindy attains peak sustained winds of , about southeast of Cameron, Louisiana.

June 22 06:00 UTC (1:00 a.m. CDT) at Tropical Storm Cindy attains a minimum barometric pressure of , about west-southwest of Cameron. 07:00 UTC (2:00 a.m. CDT) at Tropical Storm Cindy makes landfall about west of Cameron, just east of the Sabine Pass, with sustained winds of .

June 23 00:00 UTC (7:00 p.m. CDT, June 22) at Tropical Storm Cindy weakens to a tropical depression about north-northeast of Shreveport, Louisiana. 18:00 UTC (1:00 p.m. CDT) at Tropical Depression Cindy degenerates to a remnant low about west of Hopkinsville, Kentucky, and subsequently dissipates.

July

July 5 18:00 UTC (2:00 p.m. AST) at Tropical Depression Four develops from a tropical wave about east of the Lesser Antilles.

July 6 12:00 UTC (8:00 a.m. AST) at Tropical Depression Four attains its peak intensity with sustained winds of and a minimum barometric pressure of , about east of the Lesser Antilles.

July 7 12:00 UTC (8:00 a.m. AST) at Tropical Depression Four degenerates into a tropical wave roughly east of the Lesser Antilles, and subsequently dissipates.

July 17 06:00 UTC (2:00 a.m. AST) at A tropical depression develops from a tropical wave about east-southeast of Barbados. 12:00 UTC (8:00 a.m. AST) at The tropical depression intensifies into Tropical Storm Don about east-southeast of Barbados.

July 18 00:00 UTC (8:00 p.m. AST, July 17) at Tropical Storm Don attains its peak intensity with sustained winds of and a minimum barometric pressure of , about east-southeast of Barbados. 18:00 UTC (2:00 p.m. AST) at Tropical Storm Don opens up into a tropical wave about southeast of Barbados and subsequently dissipates.

July 30 18:00 UTC (2:00 p.m. EDT) at Tropical Depression Six forms from an area of low pressure about west-northwest of St. Petersburg, Florida.

July 31 00:00 UTC (8:00 p.m. EDT, July 30) at Tropical Depression Six intensifies to become Tropical Storm Emily about west of St. Petersburg. 14:45 UTC (10:45 a.m. EDT) at Tropical Storm Emily reaches its peak intensity with sustained winds of and a minimum pressure of while simultaneously making landfall about north of Longboat Key, Florida.

August

August 1 00:00 UTC (8:00 p.m. EDT, July 31) at Tropical Storm Emily weakens to a tropical depression inland, about east of Longboat Key.

August 2 00:00 UTC (8:00 p.m. EDT, August 1) at Tropical Depression Emily degenerates to a post-tropical cyclone over the Atlantic Ocean, roughly northeast of Cape Canaveral, Florida, and later dissipates.

August 7 00:00 UTC (8:00 p.m. EDT, August 6) at Tropical Storm Franklin develops from a tropical wave about north-northeast of Cabo Gracias a Dios on the Honduras–Nicaragua border.

August 8 03:45 UTC (10:45 p.m. EDT, August 7) at Tropical Storm Franklin makes landfall near Pulticub, Quintana Roo, with winds of .

August 9 00:00 UTC (7:00 p.m. CDT, August 8) at Tropical Storm Franklin emerges over the Bay of Campeche, northwest of Campeche City, Campeche. 18:00 UTC (1:00 p.m. CDT) at Tropical Storm Franklin intensifies into a Category 1 hurricane, about east-northeast of Veracruz City, Veracruz.

August 10 00:00 UTC (7:00 p.m. CDT, August 9) at Hurricane Franklin attains its peak intensity with sustained winds of and a minimum pressure of , about north-northeast of Veracruz City. 05:00 UTC (12:00 a.m. CDT) at Hurricane Franklin makes landfall near Vega de Alatorre, Veracruz, with sustained winds of near . 06:00 UTC (1:00 a.m. CDT) at Hurricane Franklin weakens to a tropical storm inland, about west-southwest of Vega de Alatorre. 12:00 UTC (7:00 a.m. CDT) at Tropical Storm Franklin weakens to a tropical depression about east-northeast of Mexico City, and later dissipates.

August 12 18::00 UTC (2:00 p.m. EDT) at Tropical Depression Eight forms from a tropical wave about northeast of the Turks and Caicos Islands.

August 13 00:00 UTC (8:00 p.m. EDT, August 12) at Tropical Depression Eight intensifies into Tropical Storm Gert about northeast of the southeastern Bahamas.

August 15 06:00 UTC (2:00 a.m. EDT) at Tropical Storm Gert intensifies into a Category 1 hurricane, about west of Bermuda.

August 16 12:00 UTC (8:00 a.m. AST) at Hurricane Gert intensifies into a Category 2 hurricane, about west-northwest of Bermuda. 18:00 UTC (2:00 p.m. AST) at Hurricane Gert attains its peak intensity with maximum sustained winds of and a minimum pressure of , about south-southeast of Halifax, Nova Scotia.

August 17 06:00 UTC (2:00 a.m. AST) at Hurricane Gert weakens to Category 1 strength, about south of St. John's, Newfoundland and Labrador. 06:00 UTC (2:00 a.m. AST) at The ninth tropical depression of the season develops from a tropical wave about east of Barbados. 12:00 UTC (8:00 a.m. AST) at Hurricane Gert weakens to a tropical storm, about south of St. John's. 18:00 UTC (2:00 p.m. AST) at Hurricane Gert transitions into an extratropical cyclone, about southeast of St. John's, and subsequently merges with another extratropical cyclone. 18:00 UTC (2:00 p.m. AST) at The ninth tropical depression intensifies into Tropical Storm Harvey about east of Barbados.

August 18 00:00 UTC (8:00 p.m. AST, August 17) at Tropical Storm Harvey attains its initial peak windspeed of , about east of Barbados. 10:00 UTC (6:00 a.m. AST) at Tropical Storm Harvey makes landfall on Barbados, with sustained winds of . 15:00 UTC (11:00 a.m. AST) at Tropical Storm Harvey makes landfall on St. Vincent, with sustained winds of .

August 19 12:00 UTC (8:00 a.m. AST) at Tropical Storm Harvey weakens to a tropical depression about west of Saint Vincent. 18:00 UTC (2:00 p.m. AST) at Tropical Depression Harvey degenerates to a tropical wave about west of St. Vincent.

August 23 12:00 UTC (7:00 a.m. CDT) at The remnants of Harvey regenerate into a tropical depression in the Bay of Campeche, about west of Progreso, Yucatán. 18:00 UTC (1:00 p.m. CDT) at Tropical Depression Harvey re-strengthens into a tropical storm about west of Progreso.

August 24 18:00 UTC (1:00 p.m. CDT) at Tropical Storm Harvey intensifies into a Category 1 hurricane, about south-southeast of Port O'Connor, Texas.

August 25 06:00 UTC (1:00 a.m. CDT) at Hurricane Harvey intensifies into a Category 2 hurricane, about south-southeast of Port O'Connor. 18:00 UTC (1:00 p.m. CDT) at Hurricane Harvey intensifies into a Category 3 hurricane, about south of Port O'Connor.

August 26 00:00 UTC (7:00 p.m. CDT, August 25) at Hurricane Harvey intensifies into a Category 4 hurricane, about south-southwest of Port O'Connor. 03:00 UTC (10:00 p.m. CDT, August 25) at Hurricane Harvey attains its peak intensity with sustained winds of and a minimum barometric pressure of , and simultaneously makes landfall on San Jose Island, Texas. 06:00 UTC (1:00 a.m. CDT) at Hurricane Harvey weakens to Category 3 intensity as it makes landfall on the northeast end of Copano Bay, near Holiday Beach, Texas. 12:00 UTC (7:00 a.m. CDT) at Hurricane Harvey weakens to Category 1 strength inland, about north-northwest of Holiday Beach. 18:00 UTC (1:00 p.m. CDT) at Hurricane Harvey weakens to tropical storm strength, about north-northwest of Holiday Beach.

August 29 18:00 UTC (1:00 p.m. CDT) at Tropical Storm Harvey attains a secondary peak windspeed of in the Gulf of Mexico, about south-southwest of Cameron, Louisiana.

August 30