Tropical Storm Bonnie formed over the Southwestern Caribbean Sea on Friday morning. At 11:00 a.m. EDT on Friday the center of Tropical Storm Bonnie was located at latitude 11.2°N and longitude 81.9°W which put it about 195 miles (315 km) east-southeast of Bluefields, Nicaragua. Bonnie was moving toward the west at 20 m.p.h. (32 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1005 mb.
A Tropical Storm Warning was in effect for San Andres Island, Colombia. A Tropical Storm Warning was in effect for the portion of the Caribbean coast from Limon, Costa Rica to Sandy Bay Sirpi, Nicaragua. A Tropical Storm Warning was also in effect for the portion of the Pacific coast from Cabo Blanco, Costa Rica to the border between Nicaragua and Honduras.
A U.S. Air Force Reserve Hurricane Hunter reconnaissance aircraft found westerly winds in the southwestern part of former Potential Tropical Cyclone Two on Friday morning. Based on data from the reconnaissance plane, the National Hurricane Center designated the system as Tropical Storm Bonnie. More thunderstorms formed in bands revolving around the center of Tropical Storm Bonnie. Storms near the center of Bonnie generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 100 miles (160 km) in the northern side of Bonnie’s circulation. Winds in the southern side of Tropical Storm Bonnie were blowing at less than tropical storm force.
Tropical Storm Bonnie will move through an environment favorable for intensification during the next 12 hours. Bonnie will move over water where the Sea Surface Temperatures are near 28˚C. It will be under an upper level ridge over the Southwestern Caribbean Sea. The upper level winds are weak in the ridge and there will be little vertical wind shear. Tropical Storm Bonnie will strengthen during the next 12 hours. Bonnie will weaken when it moves over Nicaragua and Costa Rica, but it could strengthen again over the Eastern North Pacific Ocean on Saturday.
Tropical Storm Bonnie will move south of the western part of a high pressure system over the western Atlantic Ocean and the Caribbean Sea. The high pressure system will steer Bonnie toward the west during the next 24 hours. On its anticipated track Tropical Storm Bonnie will hit southern Nicaragua and northern Costa Rica on Friday night. Bonnie will bring gusty winds and locally heavy rain to southern Nicaragua and northern Costa Rica. Heavy rain could cause flash floods and mudslides in some locations.