02 September 2019

The unimaginable: Category 5 Hurricane Dorian stationary over Bahamas

Since Sunday morning's update, Dorian intensified even further to an incredible 185 mph and a central pressure of 910 mb.  It reached that intensity just as it was making landfall on Great Abaco in the northern Bahamas, tieing the 1935 Labor Day Hurricane for most intense landfall anywhere in the Atlantic. And it gets worse. Dorian is still a Category 5 hurricane with 165 mph sustained winds and gusts to 200 mph, traveled only 105 miles in the past day, and is now stationary over Grand Bahama.

Dorian is centered over Grand Bahama, which is 120 miles east of West Palm Beach FL.  The tropical storm force winds extend an average of 120 miles from the center, and the hurricane force winds extend an average of 35 miles from the center.

Hurricane warnings remain in effect for the northern Bahamas as well as the central Florida coast. A hurricane watch and storm surge warning extends from Boca Raton up the Georgia state line.  As of 8am EDT on Monday, the motion in the NHC advisory is given as west at 1 mph.  A person typically *walks* at 3 mph.
The threat to much of the east coast of Florida is still extreme, and the eastern parts of GA, SC, and NC also need to be preparing for a major impact, including significant storm surge.  The HTI (Hurricane Threats & Impacts) graphics break down the four major hurricane hazards: wind, surge, rain, and tornadoes:

Dorian is expected to remain nearly stationary until Tuesday morning, when a very gradual northward drift should begin. Of course, just how close Dorian gets to the coastline is critical to impacts like wind and storm surge. It is an extremely serious threat and easily within the bounds of normal forecast error. Do not focus on the exact track or the edge of the cone -- neither of them are designed to show impacts. We can monitor the position, eyewall structure, and rainbands from several long, updating radar loops at http://bmcnoldy.rsmas.miami.edu/tropics/radar/.  For example, this one from Miami begins on Sunday morning and as of this post, ends at 9:30am EDT on Monday:

From the latest 50-member European model ensemble, 4 of the members make landfall south of Cape Canaveral, about 6 show a landfall around Cape Canaveral, while the remaining 80% remain either just offshore or well offshore.  The tracks shown here are only plotted out to 4 days.

Other than Dorian, the Atlantic looks like early September: busy. There are three disturbances with >50% odds of becoming at least tropical depressions in the next five days. The next three names on the list are Fernand, Gabrielle, and Humberto.


  1. As always we are thankful for your knowledge and no-nonsense forecasting of the tropics.

  2. Great information Brian, greatly appreciated, especially the wind and rain contour maps so we can see what to expect in our particular location.