11 AM EDT 28 September 2016 Update
Matthew has formed over the Windward islands as 60MPH Tropical Storm, and the forecast takes it to hurricane strength in the Eastern Caribbean in 48 hours. Those in Jamaica and the Southern Caribbean islands should watch Matthew closely.
8 AM EDT 27 September 2016 Update
Chances are now up to 90%, so it is likely a depression or storm will form later today from 97L. This system already has a developed appearance and conditions ahead of it are favorable for more development. Those in the central and southern lesser Antilles will likely feel impacts of this tomorrow into Thursday.
Beyond that, those in the southern Caribbean Islands, and Jamaica will want to watch it closely, too soon to tell beyond that, but it's worth keeping tabs on in the Bahamas, Hispaniola, Cuba and the Southeastern United States..

More speculation on 97L can be found in the forecast lounge.
Original Update
Tropical Storm Karl has passed by Bermuda and is now on the way out to sea, the attention now moves to the wave in the central Atlantic being tracked as invest 97L. This system will likely have some impacts in the central to southern leeward islands and Windwards mid week around Wednesday, and beyond that move into the Caribbean. There is an 80% chance this system will develop over the next 5 days. Beyond that it it is too soon to tell, but will likely need to be watched closely by those in the Caribbean, Bahamas, Florida, and the Gulf to see where it ultimately goes.
Any impacts to the US wouldn't be until next week (Oct 6-9), there is a good chance the system stays east, but in that case there would be more impact felt in the Caribbean and Bahamas. It's still a ways out with a undeveloped system so speculation beyond a few days is a bit counterproductive, but the system is worth watching.
More speculation on 97L can be found in the forecast lounge.
Matthew Event Related Links
SFWMD Model Plot (Animated Model Plot) SFWMD Hurricane Page
[https://flhurricane.com/floatanimator.php?year=2016&storm=14 Flhurricane Satellite Floater Animation of Matthew
GOES Floater
Animated Model Plot of Matthew
Clark Evans Track Model Plot of Matthew
(Animated!) Model Plots in Google Earth - In Google Maps
Clark Evans Intensity Model Plot of Matthew (Animated!)
Clark Evans Track Plot of Matthew
Other Model Charts from Clark
Clark Evans Top 10 Analog Storms for Matthew
More model runs on from RAL/Jonathan Vigh's page
NRL Info on Matthew -- RAMMB Info
COD Atlantic Satellite View
TS Karl Event Related Links
SFWMD Model Plot (Animated Model Plot) SFWMD Hurricane Page
[https://flhurricane.com/floatanimator.php?year=2016&storm=12 Flhurricane Satellite Floater Animation of Karl
GOES Floater
Animated Model Plot of Karl
Clark Evans Track Model Plot of Karl
(Animated!) Model Plots in Google Earth - In Google Maps
Clark Evans Intensity Model Plot of Karl (Animated!)
Clark Evans Track Plot of Karl
Other Model Charts from Clark
Clark Evans Top 10 Analog Storms for Karl
More model runs on from RAL/Jonathan Vigh's page
NRL Info on Karl -- RAMMB Info
COD Atlantic Satellite View
StormCarib Reports from the Caribbean Islands
Caribbean Weather Observations
Barbados Brohav Weather Fax
Full Caribbean Radar Composite
Caribbean Broadcast Corporation (TV/Radio from Antilles)
San Juan, PR NWS Page
Various Caribbean Radio Stations
DR1 Dominican Republic Hurricanes