Dorian is now just past St. Lucia/St. Vincent. The storm is still hovering around 50mph wind speeds, a middling tropical storm, and from the current (6:30am ET) high resolution satellite image showed some big thunderstorms are passing over Martinique. The dry air in the mid levels of the atmosphere in the Caribbean is keeping the storm suppressed, and development seems to be stalled. The present National Hurricane Center forecast has backed off on forecasting the storm to become a hurricane before it reaches Puerto Rico and the Dominican Republic (the eastern half of the island of Hispaniola), although there are still hurricane watches up for both. Preparations in PR and the eastern DR for a strong tropical storm or minimal hurricane make sense at this point, especially for the inevitable localized flash flooding that accompanies these storms. Wednesday will likely be a wet and blustery, but hopefully not catastrophic day for them.
As to what happens next, it depends on some subtle wobbles and not so subtle mountains. If the storm threads the Mona passage between the islands of Hispaniola and Puerto Rico, it could maintain its circulation enough to rebound in the warm waters of The Bahamas. This is the scenario NHC is showing. Butf it wobbles either left or right of this track, it could well be shredded, and the islands and Florida just get a messy tropical rain system. Hard to tell at this point, but by tomorrow we will have a better handle on this since we will know how much the dry air inhibits (or even decreases) the storm, and if is going to run aground on Hispaniola. The obligatory “spaghetti map” shows the primary dynamic models taking the storm as the NHC has it, mostly towards the Dominican Republic. This map is showing all of the available tracks … for those of you in Georgia/SC/NC, don’t freak out about the lines headed up towards your area. Those are mostly ensemble track members that are low probability outcomes, and often represent tracks where the storm is little more than a big thunderstorm. They are designed to help understand the uncertainty in the forecasts. It is pretty irresponsible to cherry pick from those tracks, as some local weathercasters and amateurs do. The colored lines are the “primary” model tracks that are the ones to examine – but that red line is the Official NHC Track that is the one to care about.