We’re tracking what has the chance of becoming the first tropical cyclone of the 2018 Atlantic hurricane season, which officially begins on June 1st, but as you may know Mother Nature does not like to follow a schedule. This potential tropical cyclone will likely be a subtropical storm, if it develops at all, due to the non-fully tropical characteristics.
A slow-moving, large dome of high pressure off the East Coast of the United States will keep moisture to the south associated with this tropical wave, thus helping to focus the rain and thunderstorms across the Great Antilles. Rounds of rain and thunderstorms moving from east to west will persist from now through at least this coming weekend. This includes the Bahamas, Cuba, Turks and Caicos, Haiti, the Dominican Republic, Puerto Rico, and the Virgin Islands. All of the islands plus more are likely to experience days of rain, which will be heavy at times. Some areas will receive over half a foot of rainfall, which will lead to flooding. Flooding will be the main threat as well as enhanced winds with gusts over 40 mph from this tropical wave.
The odds of this tropical wave developing into a tropical cyclone are low, but not zero. Sea surface temperatures are up to a several degrees above average north of the Caribbean Sea and near the Gulf Stream. That is a positive which may help this disturbance to develop, but the very strong wind shear, another component we look at for tropical forecasting, will likely prevent the development. Wind shear prevents tropical cyclones from developing because it does not allow the thunderstorms to organize and spin around a centralized low pressure. Either way, heavy rain and flooding will be the main threats with this tropical wave no matter whether it develops into a tropical system or not.
This general region will remain stormy into much of next week. Rounds of storms will also work into South and Central Florida beginning this weekend.