A risk posed by Tropical Storm Idalia prompted the issuance of a Hurricane Watch for part of the west coast of Florida. At 5:00 p.m. EDT on Sunday the center of Tropical Storm Idalia was located at latitude 20.1°N and longitude 85.5°W which put it about 95 miles (155 km) east-southeast of Cozumel. Idalia was moving toward the northeast at 3 m.p.h. (5 km/h). The maximum sustained wind speed was 40 m.p.h. (60 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 995 mb.

A Hurricane Watch was in effect for the portion of the coast from Englewood to Indian Pass, Florida. The Hurricane Watch included Tampa Bay. A Tropical Storm Warning was in effect for the portion of the coast from Tulum to Rio Lagartos, Mexico. The Tropical Storm Warning included Cozumel. A Tropical Storm Warning was also in effect for the Cuban Province. of Pinar del Rio. A Tropical Storm Watch was in effect for the portion of the coast from Englewood to Chokoloskee, Florida. A Tropical Storm Watch was also in effect for the Dry Tortugas. A Tropical Storm Watch was in effect for the Isle of Youth.

Tropical Storm Idalia did not change a lot on Sunday afternoon. A few more thunderstorms developed near the low level center of circulation. The low level center of circulation was meandering around inside of a larger counterclockwise rotation over the Northwestern Caribbean Sea. There were bands of showers and thunderstorms in the larger counterclockwise circulation. The thunderstorms in the larger circulation generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 70 miles (110 km) from the low level center of circulation.

Tropical Storm Idalia will be in an environment mostly favorable for intensification during the next 24 hours. Idalia will be over water where the Sea Surface Temperatures are near 30°C. It will be under an upper level ridge over the Yucatan Channel. The winds are weak in the upper level ridge and there will be little vertical wind shear. However, much of the air moving around the western side of Tropical Storm Idalia will pass over the northeastern Yucatan Peninsula. Some of the air in the eastern side of the Idalia will pass over western Cuba. The flow of air over land will inhibit intensification, but it probably will not prevent intensification. Tropical Storm Idalia could intensify slowly during the next 12 hours. Idalia could intensify more quickly on Monday when it moves over the eastern Gulf of Mexico. Tropical Storm Idalia is forecast to strengthen to a hurricane by Monday night

.Tropical Storm Idalia will be in a region where the steering currents are weak during the next 12 hours. Idalia may not move much during that time period. A high pressure system over the western Atlantic Ocean will start to steer Idalia toward the north on Monday. On its anticipated track Tropical Storm Idalia will move over the eastern Gulf of Mexico on Monday. An upper level trough over the eastern U.S. could start to turn Idalia toward the northeast later on Tuesday.

Tropical Storm Idalia will drop heavy rain over parts of the northeastern Yucatan Peninsula and western Cuba. Heavy rain could cause flash floods in some locations.

Tropical Storm Idalia is forecast to be a hurricane when it reaches the west coast of Florida. Idalia is likely to make landfall in an area where high storm surges can occur. Idalia could cause a storm surge of up to 11 feet (3.3 meters) near where the center makes landfall. A Storm Surge Watch has been issued for the portion of the coast from Chokoloskee to Indian Pass, Florida. The Storm Surge Watch includes Tampa Bay.

Elsewhere, Hurricane Franklin was over the Atlantic Ocean southwest of Bermuda. At 5:00 p.m. EDT on Sunday the center of Hurricane Franklin was located at latitude 25.9°N and longitude 70.0°W which put it about 535 miles (855 km) southwest of Bermuda. Franklin was moving toward the north-northwest at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h). The minimum surface pressure was 970 mb.