Karl passed within about 60 miles of Bermuda in the over night hours bringing tropical storm conditions to the area. The storm is now moving away and will do so with increasing forward speed throughout the weekend. Winds and seas will subside and by sunset this evening, it will be quite gorgeous in Bermuda. There is still a chance that Karl becomes a hurricane over the open Atlantic but it will only be an issue for shipping lanes.
As we say goodbye to Karl, we will need to become more and more vigilant as we monitor a tropical wave and low pressure area moving across the deep tropics. This one has potential for becoming a strong hurricane at some point as all signs point to a change in the conditions that have been preventing the storms this season from reaching their full potential.
The GFS model in particular has been extremely consistent with its run to run depiction of a gradually developing tropical cyclone headed right for the eastern Caribbean Sea. We’re not talking five or seven days out any longer, this looks like it could happen as early as Monday with a possible tropical storm threatening the Windward Islands.
Right now, satellite data indicates a large area of energy associated with a tropical wave that moved off of Africa a couple of days ago. The moisture content is high, also known as precipitable water. There is increasing vorticity meaning spin in the atmosphere and water temperatures are plenty warm. I see no reason to believe that this system won’t develop as it moves steadily west over the coming days. In fact, the NHC is now indicating a 50% chance of development over the next five days and says that a tropical depression could form as it approaches the Lesser Antilles.
For now my concern is for the Lesser Antilles and specifically the Windward Islands. It is impossible to know which area could see the most significant impacts from a system that has not even developed yet. This one looks like the real deal and as such, interests in the Lesser Antilles and eastern Caribbean as a whole need to be paying attention to this feature. Even if it is slower to develop than the GFS is indicating, the threat of heavy rain seems to be almost a certainty at this point. Anything beyond that will be determined by just how quickly it organizes over the next few days.
M. Sudduth 7:30 AM ET Sept 24