Wednesday, September 4, 2019

Dorian Part 1 - Cluster of Thunderstorms to Tropical Beast

Tonight Hurricane Dorian is affecting the southeastern U.S. coast. The center of the eye is roughly 100 miles off the coast, and it's precipitation shield extends inland 30 miles or less from the northern Florida coast up through Georgia and into South Carolina. We have already been following Dorian for 11 days.

The first advisory for then Tropical Depression #5 was issued during the morning on August 24th. Later that day Tropical Depression #5 became Tropical Storm Dorian.

On Wednesday, August 28 Dorian strengthened into a hurricane near St. Thomas in the U.S. Virgin Islands. Dorian steadily strengthened the next 48 hours, becoming a major category 3 hurricane on Friday morning, August 30. Dorian rapidly strengthened to a Category 4 hurricane by Friday evening. Dorian became a Category 5 hurricane sometime near dawn on Sunday, September 1, just 40 miles or so east of Great Abaco island in the northwest Bahamas.

Track of Hurricane Dorian from August 24 to 5:00 p.m. EDT September 4.

Satellite infrared image of Hurricane Dorian at 6:00 p.m. EDT on August 31. At this time Dorian was a Category 3 hurricane and quickly ramped up to a Category 4 within three hours.
Radar image from the Bahamian Weather Service showing Dorian at 4:00 pm EDT on September 1. At this time the eye was moving over Great Abaco with sustained winds up to 185 mph and gusts to 220 mph

For the next 40 hours the combination of 155 to 185 mph+ winds in Dorian's eyewall and storm surge exceeding 20 feet of water produced catastrophic damage across Great Abaco and Grand Bahama islands as the storm virtually came to a standstill. Buildings not damaged or destroyed by the winds were likely "protected" by the deep water that submerged them.

These two radar images, 12.5 hours apart show how little Dorian moved during the time period while the eye was over Grand Bahama Island. During this time sustained winds were sustained around 155 mph with gusts to 195 mph.

As of this writing the death toll in the Bahamas is 20, and is likely to go higher.

Tonight (September 4) Dorian has re-intensified to a Category 3 hurricane and is likely headed to the Outer Banks of North Carolina. 2.3 million people in the Southeast are under evacuation orders. It will be another several days before Dorian is no longer something to worry about. For the latest information on Dorian visit the National Hurricane Center website.


  1. Buildings not damaged or destroyed by the winds were likely "protected" by the deep water that submerged them.

    Wow, that never occurred to me. Wave action with debris in the water as the surge moved in would have been a problem, but that would have happened before the 200 mph wind gusts arrived.

  2. No storm has ever done the damage to a region this one did. Dorian's stall meant that there were placesin the N Bahamas that spent nearly a day facing 20+ ft surge and over 200 mph gusts. Unprecidented and horrific.

  3. My extended family lost everything - their home, his livelihood (fisherman)and the school she founded for special needs children. Very sad.