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.

Simultaneously, relaxing wind shear and warm sea surface temperatures allowed Dorian to become a Category 1 hurricane as it moved over the United States Virgin Islands.

The system reached peak intensity later that day, with winds of 185 mph (295 km/h) and a central pressure of 910 mbar (hPa; 26.87 inHg) while making landfall on Elbow Cay in The Bahamas.

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.

[5] 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.

[3][8] 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.

[9] 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.

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.

[10] Dorian soon took 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.

[11] 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.

The hurricane progressed northwestward under the influence of flow between an upper-level low over the Straits of Florida and the Atlantic subtropical ridge.

[3] Additional strengthening was forecast as the storm would remain in a favorable environment with an increasingly moist mid-level, with 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,[12] dry air and southwesterly wind shear caused Dorian's intensification to temporarily stagnate before decreasing again.

[16][17] A Hurricane Hunter aircraft revealed that Dorian rapidly intensified to Category 4 status at 00:00 UTC on August 31, with surface winds measured to be near 130 mph (215 km/h).

The eye also began to demonstrate a pronounced stadium effect, where the clouds of the eyewall curved outward from the surface with height; this is a feature at times seen in intense tropical cyclones.

[3] Around 12:00 UTC, the NHC estimated the one-minute sustained winds to have reached 180 mph (285 km/h), making Dorian the strongest hurricane to impact The Bahamas on record.

[19] Further deepening occurred over the next couple of hours, with maximum sustained winds reaching 185 mph (295 km/h) and the minimum central pressure dropping to 910 mbar (hPa; 26.87 inHg), representing Dorian's peak intensity.

Creeping slowly westwards, Dorian weakened slightly before making landfall near South Riding Point, Grand Bahama with winds of 180 mph (285 km/h) at 02:15 UTC on September 2.

[22] Dorian slowly weakened over the next day after entering an area of cooler sea surface temperatures and high wind shear.

[31] Soon after, cold air clouds began to entrain on Dorian's southwestern side, as the storm connected with a warm front that was developing to the northeast.

[43] The storm also impacted a single land area as a Category 5 hurricane for the longest duration recorded in the Atlantic basin, with portions of Dorian's eyewall striking Great Abaco Island and Grand Bahama for about 22 hours.