Once the low pressure system forms, it's expected to move northwest through conducive environmental conditions, hurricane forecasters said at 1 p.m. Thursday. The disturbance had no chance of forming into a tropical depression or storm within the next two days Thursday afternoon and a 20% chance of forming in the next week.

Tropical Storm Helene formed in the northwestern Caribbean Sea on Tuesday, but National Hurricane Center forecasters expected the storm to quickly turn into a hurricane by Wednesday as it enters the unusually warm waters of the Gulf of Mexico.