The disturbance that has been tracking across the southern Caribbean Sea has intensified into Tropical Storm Bonnie based on an Air Force Reserve Hurricane Hunter finding a well-defined circulation center located about 100 n mi east of the Nicaragua coast. The max winds are still only about 35 knots. Bonnie is moving just south of due west at 260/17 knots and is forecast to emerge over the tropical North Pacific on Saturday.
Bonnie remains in a low-shear and warm SST environment and is forecast to intensify during the next 12 hours prior to landfall. Heavy rainfall is likely across portions of Nicaragua and Costa Rica today into Saturday. Areas of life-threatening flash flooding and mudslides are expected. Tropical storm conditions are expected on San Andres today, along the Caribbean coasts of Costa Rica and Nicaragua within the Tropical Storm Warning areas by this evening, and along the Pacific coasts of Costa Rica and Nicaragua overnight and early Saturday.