Caribbean Sea: Tropical Storm Helene tracking west-northwestward across the northwestern Caribbean Sea as of late Sept. 24 /update 2

Tropical Storm Helene is tracking west-northwestward across the northwestern Caribbean Sea late Sept. 24. As of 22:00 CDT, the system's center of circulation was approximately 160 km (100 miles) east-southeast of Cozumel, Mexico.

Forecast models indicate that the storm will strengthen into a Category 1 hurricane as it passes through the Yucatan Channel close to the northeastern coast of Quintana Roo State, Mexico, early Sept. 25. Helene is expected to strengthen further into a Category 3 hurricane as it tracks northward and then north-northeastward over the Gulf of Mexico Sept. 25-26, before making landfall over the Big Bend region of Florida late Sept. 26. After landfall, the system is expected to weaken into a tropical storm as it tracks northward over Georgia early Sept. 27, before weakening further and dissipating as it tracks north-west-northwestward over central Tennessee the far western Kentucky Sept. 26-late Sept. 28. Some uncertainty remains in the track and intensity forecast, and significant changes could occur over the coming hours and days.

As of late Sept. 24, authorities have issued the following watches and warnings:

Hurricane Warning

• Anclote River to Mexico Beach, Florida

• Cabo Catoche to Tulum, Mexico, including Cozumel

Hurricane Watch

• Englewood to Anclote River, Florida, including Tampa Bay

• Pinar del Rio Province, Cuba

Tropical Storm Warning

• Rio Lagartos to Cabo Catoche, Mexico

• Artemisa and Pinar del Rio provinces and the Isle of Youth, Cuba

• Dry Tortugas, Florida

• Lower and Middle Florida Keys west of the Channel 5 Bridge, Florida

• Flamingo to Anclote River, Florida, including Tampa Bay

• West of Mexico Beach to the Walton/Bay County Line

• Palm Beach/Martin County Line northward to the Flagler/Volusia County Line

• Lake Okeechobee, Florida

Tropical Storm Watch

• Flagler/Volusia County Line northward to the Savannah River

Storm Surge Warning

• Indian Pass southward to Flamingo, Florida

• Tampa Bay, Florida

• Charlotte Harbor, Florida

Authorities will likely update and extend the coverage of the weather advisories over the coming hours and days as the storm system develops.

Hurricane conditions are expected in the hurricane warning area in Mexico Sept. 25 and expected within the US hurricane warning area late Sept. 26. Tropical storm conditions are expected to begin in the tropical storm warning area in Florida Sept. 25, spread northward through Sept. 26, and are possible within the tropical storm watch area Sept. 26.

The storm is forecast to generate rainfall amounts of 10-20 cm (4-8 inches) with isolated higher totals of around 30 cm (12 inches) across parts of western Cuba, the Cayman Islands, and the northeast Yucatan Peninsula in Mexico. Rainfall amounts of 10-20 cm (4-8 inches) with isolated higher totals around 30 cm (12 inches) are expected over parts of the southeastern US. The heavy downpours could trigger considerable flash and urban flooding and significant riverine flooding. Landslides are possible in areas of steep terrain in the southern Appalachians. Isolated tornadoes are possible over parts of the western Florida peninsula and southern Alabama late Sept. 25 before spreading across Florida and into parts of Georgia and South Carolina Sept. 26.

Storm surge could raise water levels by as much as 0.6-1.2 meters (2-4 feet) above normal tide levels in areas of onshore winds along the southern coast of Pinar del Rio, Cuba, including the Isle of Youth, and along the eastern coast of the Yucatan Peninsula, Mexico. Peak surge could reach up to 3-4.5 meters (10-15 feet) between the Ochlockonee River and Chassahowitzka in Florida and 0.9-3 meters (3-10 feet) along other parts of the western Florida coast. Swells generated by Helene will affect the southern coast of Cuba and the Yucatan Peninsula of Mexico over the coming days and will spread northward toward the west coast of Florida and the northeastern Gulf Coast Sept. 25-26. These swells are likely to cause life-threatening surf and rip current conditions.

Florida Gov. Ron DeSantis has declared a state of emergency across 41 of the state's 67 counties. Mandatory evacuation orders are in place for parts of Citrus, Hillsborough, Manatee, Pinellas, Taylor, and Wakulla counties, as well as for barrier islands, low-lying and flood-prone areas, especially along the coast and rivers, mobile homes, and RV parks in Charlotte, Franklin, and Gulf counties. Authorities will likely issue further mandatory and voluntary evacuation orders across counties along the Panhandle, Tampa Bay area, and west coast of Florida as the storm approaches.

Sir Captain Charles Kirkconnell International Airport (CYB) and Owen Roberts International Airport (GCM) in the Cayman Islands closed late Sept. 23 until further notice. Cruise ship arrivals at ports in Quintana Roo State, Mexico, have been canceled late Sept. 24-25. Oil companies have evacuated personnel from some production platforms in the Gulf of Mexico.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. If weather conditions prove hazardous, localized evacuations, flash flooding, and landslides are possible.

Inclement weather could trigger localized business, transport, and utility disruptions, rendering some bridges or roadways impassable. Flight disruptions at regional airports and temporary port closures are also possible. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a serious health threat.