Unlike Danny, which was doomed by dry air and shear almost from the get go. Erika’s path is into an area were slow, but steady intensification is likely. If Erika makes it through the dry air and shear of the next 48-72 hrs and gets into the extreme southern Bahamas, then it will be able to intensify much more. There is still a big “If” that happens.
Here’s a look at the 8 am forecast from NHC.
The Mid-Atlantic Ridge is the what’s driving Erika northwest. The real question is where the weakness or trough between the 2 areas of high pressure develops this weekend. There is a narrow corridor for the turn to the north and possible re-curvature off the east coast. The question is how sharp and quickly that turn happens. The longest it takes for that turn the more of a threat Erika could be to the Southeast coastline.
If you notice almost all the guidance keeps Erika around tropical storm strength for the next 72 hours or so, when it will be in an area of drier environmental air and mild wind shear.
Then after 72 hrs:
By early Saturday is when it becomes much more favorable for the storm to develop into a hurricane. This weekend into early next week. Low shear, moist air and very warm water.
High-End Model Possibilities:
The most aggressive models with intensity are the ECMWF, HWRF and the GFDL. These are all single model runs and going out about 5-7 days so take them with a big grain of salt. These are just possibilities right now but what they do show is the highest chance for intensification will be in the Bahamas and off the Southeast coast.
Very warm water, low wind, shear and moist air would all lead to a stronger system by this weekend into early next week.
GFS model is much weaker with the system by next week. Mainly because of interaction with Florida.
What to watch for:
The track is still very uncertain beyond 72 hrs, but all eyes should be on Erika over the next 5 days. If you live on the Southeast coast or are traveling in that direction. You should keep tabs on the storm but don’t change your plans. Still plenty of time and uncertainty, especially in intensity. Which has a very high error rate in the long-range guidance. It’s that time of the year so stay weather aware, prepare but don’t freak out.