page_title: Meteorological history of Hurricane Dorian
section_title: Origins and track through the Lesser Antilles
hierarchical_section_title: Meteorological history of Hurricane Dorian / Origins and track through the Lesser Antilles
caption_attribution_description: English: Hurricane Dorian on August 28, 2019
context_page_description: Hurricane Dorian was the strongest hurricane to affect the Bahamas on record, causing catastrophic damage in the Abaco Islands and Grand Bahama in early September 2019. The cyclone's intensity as well as its slow forward motion near the Bahamas broke numerous records. The fifth tropical cyclone, fourth named storm, second hurricane, and first major hurricane of the 2019 Atlantic hurricane season, Dorian originated from a westward-traveling tropical wave that departed from the western coast of Africa on August 19. The system organized into a tropical depression and later a tropical storm, both on August 24.
  The newly formed Dorian strengthened only gradually over the next few days because of dry air and vertical wind shear. On August 27, Dorian made landfalls on Barbados and St. Lucia before entering the Caribbean Sea. Dorian's structure was seriously disrupted after encountering the mountains of St. Lucia, causing the system's center to reform north of its previous location. Moving farther north and east than anticipated, Dorian passed east of Puerto Rico on August 28.
context_section_description: Hurricane Dorian originated from a large tropical wave –  an elongated trough of low air pressure –  that departed from the western coast of Africa on August 19, 2019. Around that time, much of the wave's convection or thunderstorm activity was located inland near Guinea and Senegal rather than close to its center. Thunderstorms in the northern portion of the wave were limited by an abundance of Saharan dust in the region. While the wave traveled westward across the low latitudes of the Atlantic, it lost most of its convection before a low-pressure area developed on August 22. Despite being located in an area of moderate vertical wind shear, the system continued to increase in organization. The National Hurricane Center (NHC) initially predicted slow development on August 23 as the system continued westward, however, the system organized into a tropical depression at 06:00 UTC on August 24, while approximately 805 mi (1,295 km) east-southeast of the island of Barbados. 
  Early in the depression's existence, its southeastern outflow was restricted due to moderate easterly wind shear. The system was upgraded into Tropical Storm Dorian at 18:00 UTC after developing a 10-mile (15 km) wide eye-like feature at its mid-levels and banding features that wrapped around it. Dorian initially intensified while it was located in an environment of warm sea surface temperatures. This trend all but ceased over the next few days as a result of wind shear as well as abundant mid-level dry air. With little change in intensity, Dorian made landfall over Barbados around 01:30 UTC on August 27 with maximum sustained winds of 50 mph (85 km/h), entering the Caribbean Sea. At that time, composite radar showed that the system lacked a strong inner core. The tropical storm made its second landfall on St. Lucia around 11:00 UTC at the same intensity; the mountainous terrain of the island disrupted the low-level circulation of the system. Soon after, Dorian's center re-developed farther north. Meanwhile, the storm's convection fluctuated as the system continued to be affected by dry air and interacted with the Leeward and Windward islands. Dorian briefly developed a 10-mile (15 km) wide eye on radar on a couple occasions, but it quickly eroded because of mid-level dry air incursions. 
  Dorian soon took on a more northwesterly direction as a result of a weakness in a ridge caused by a mid- to upper-level low (cold-core cyclone) located to the north of the island of Hispaniola. Although Dorian was initially forecast to make landfall on Hispaniola and subsequently weaken or dissipate over the island, the system's track shifted east of Puerto Rico by August 28 as a result of northerly directional change as well as the center reformation. Dorian's structure began to improve on the same day, with banding features becoming more prominent and a partial eyewall forming. As Dorian strengthened into a Category 1 hurricane on the Saffir–Simpson scale, it made landfall over St. Croix and St. Thomas in the United States Virgin Islands at 15:30 UTC and 18:00 UTC, respectively. Meanwhile, the cloud pattern of the tropical cyclone was continuing to increase in organization, with an eye becoming apparent on satellite imagery. The hurricane progressed northwestward under the influence of flow between an upper-level low over the Straits of Florida and the Atlantic subtropical ridge. Additional strengthening was forecast as the storm would remain in a favorable environment with an increasingly moist mid-level, sea temperatures near or over 84 °F (29 °C), and low wind shear. Even though the storm had strengthened and developed a more defined eye, dry air and southwesterly wind shear caused Dorian's intensification to temporarily stagnate before they decreased again. Later on August 29, a NOAA Hurricane Hunter aircraft reported the presence of concentric eyewalls, indicating that an eyewall replacement cycle had commenced. The aircraft also discovered that the central pressure had fallen. The plane did not find any stronger winds as Dorian continued to track towards the nort
caption: Tropical Storm Dorian passing by Puerto Rico and over the Virgin Islands on August 28
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