From the National Hurricane Center:
1. Southwestern Atlantic:
A trough of low pressure over the southwestern Atlantic Ocean continues to produce a broad area of disorganized showers and thunderstorms. A surface low pressure system is forecast to emerge along the northern portion of the trough axis later tonight or on Friday, and some subsequent development could occur through Saturday. By late Saturday, upper-level winds are forecast to become less conducive for development, and the low is expected to begin interacting with an approaching frontal system.
Formation chance through 48 hours...low...30 percent
Formation chance through 5 days...low...30 percent
2. Eastern Caribbean:
An area of low pressure is expected to form over the eastern Caribbean Sea this weekend, possibly related to the southern portion of an existing trough of low pressure over the area. Environmental conditions are forecast to be conducive for gradual development, and a tropical depression could form early next week while the disturbance moves generally westward or west-northwestward over the central Caribbean Sea.
Formation chance through 48 hours...low...near 20 percent
Formation chance through 5 days...medium...70 percent