From the image to the right, you can see plenty of moisture associated with the system as t-storms surround the center.
The darker reds and oranges give you an idea of where the higher colder cloud tops are, this is where you will find most of the rain.
Outflow can be detected to the Southwest and Northwest sectors.
As of this writing, Katia will continue to move rather rapidly to the West-Northwest at around 20 mph. It will pass over very warm waters and little in the way of shear. Most forecasts place Katia Northeast of Puerto Rico as a Category 3 by Sunday.
Below you will find the latest suite of model runs. They agree that Katia will get pushed almost due west by the Bermuda high for about 5 days. By then, it should be within a few hundred miles of the Leeward islands. Models also indicate strong upper winds will come out of the East Coast and push the Bermuda high east. This will open a gap in the atmosphere for Katia to take.
It sounds simple enough, but a handful of models do not agree on the timing of this path to open, and it may travel farther west. If this happens, the Lesser Antilles may need to follow Katia a bit more carefully.
In the long run, the East Coast and Bermuda may be dealing with it.
This is the official forecast cone from NHC out 5 days.