Nat’l Hurricane Center releases detailed timeline on Hurricane Dorian
Strongest hurricane to hit northwest Bahamas on record
JACKSONVILLE, Fla. – The National Hurricane Center released a detailed Tropical Cyclone Report extensively detailing the entire life of Hurricane Dorian, which stretched from Aug. 24 through Sept. 7.
Dorian, well before being named Dorian, began as a large tropical wave moving off the coast of Africa on Aug. 19. Signs of convection began on Aug. 22 with slight organization. Visible satellite imagery showed the beginning signs of circulation within the lower clouds.
The system reached Tropical Depression strength at 0600 UTC on Aug. 24 about 700 nautical miles east-southeast of Barbados and the Windward Islands. The system went on to become better organized- showing curved connection bands wrapping around an eye-like area.
The first fly through on Aug. 27 by an Air Force reconnaissance plane showed poor organization with peak winds around 45 knots. Dry air intrusions kept the system weaker and less organized.
Dorian’s first landfall was over Barbados as a compact cyclone with 45 knot winds. The system passed directly over St Lucia at 1100 UTC on Aug. 27. The mountains of the Windward islands acted as a disruption to the system.
Once the system passed over the islands, it began to show signs of intensification and organization, becoming a hurricane with 65 knot winds while moving near the eastern tip of St Croix at 1530 UTC. Later that day an eye was observed and 70 knot winds by 1800 UTC.
Next came a period of intensification and organization:
As the high pressure to the North of Dorian weakened, the steering currents collapsed, and the hurricane moved slowly westward, pounding the Great Abaco for several hours with it’s greatest fury. The island experienced at least tropical storm forced winds for about 3 days.
The eye made landfall near South Riding Point on Grand Bahama near 0215 UTC on Sept. 2 with 155-kt winds. It exited along the north coast of the island 6 hours later.
News4JAX went to the hardest hit areas of the Bahamas after the storm, and produced a documentary, “96 Hours of Anguish,” showing the devastation and turmoil left behind after the storm.
A large mid-level trough over the eastern United States swung eastward, and contributed to a flow pattern that favored Dorian turning north-northwestward and northward at about 5 to 10 kt. This kept the intense core of the hurricane east of Florida during the period from 3–5 September, saving our area from damage or flooding.
The hurricane then weakened as it moved northward toward an environment of high shear and cooler waters. But, as its core moved over the Gulf Stream, Dorian re-strengthened back to category 3 status offshore of the coasts of Georgia and South Carolina.
Dorian’s large eye passed directly over a NOAA buoy just offshore of the coast of South Carolina around 1600 UTC on Sept. 5 where a pressure of 959.2 mb was recorded
Dorian continued its northeastward motion, its eye passing near the Outer Banks of North Carolina for several hours and making landfall over Cape Hatteras at 1230 UTC on Sept. 6 with 85-kt winds. These category 2 winds occurred mostly over water in the eastern semicircle, and it is analyzed that North Carolina experienced category 1 winds.
After clearing the Outer Banks, the hurricane accelerated northeastward, embedded within the mid-latitude flow. Dorian became a strong post-tropical cyclone at 1800 UTC on Sept. 7 before it reached Nova Scotia, Canada.
The cyclone’s winds increased, and the circulation expanded due to baroclinic effects. The broad central circulation of the post-tropical cyclone moved rapidly across Sambro Creek, Nova Scotia, around 2200 UTC on Sept. 7, bringing hurricane-force wind gusts to a large portion of Atlantic Canada.
Dorian then became fully extratropical over the Gulf of St. Lawrence at 0600 UTC on September 8th and was finally absorbed by a larger extratropical low by 0600 UTC on Sept. 9 over the far northern Atlantic Ocean.
Copyright 2020 by WJXT News4Jax - All rights reserved.