The storm is forecast to weaken soon before undergoing a period of restrengthening and potentially becoming a hurricane on Monday.

Tropical Storms Henriette and Ivo are expected to develop into hurricanes in the Pacific, the National Hurricane Center says.

The four "zones" are expected to spawn storms in the Caribbean, the southeast coast of the U.S., the Gulf Coast of the U.S. and the Lesser Antilles, though most of those storms will just involve downpours. Dexter started forming this week.