Gulf of Mexico: Hurricane Helene tracking north-northeastward across the Gulf of Mexico as of Sept. 26 /update 5

Hurricane Helene has strengthened into a Category 2 hurricane and is tracking north-northeastward in the Gulf of Mexico Sept. 26. As of 10:00 CDT, the system's center of circulation was approximately 405 km (255 miles) southwest of Tampa, Florida.

Forecast models indicate that the storm will strengthen further into a Category 3 hurricane as it tracks north-northeastward over the Gulf of Mexico Sept. 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 western Georgia early Sept. 27, before weakening further and transitioning into a post-tropical cyclone as it tracks northwestward over central Tennessee Sept. 27. The remnants of the system are expected to stall over northern Tennessee late Sept. 27-early Sept. 29. Some uncertainty remains in the track and intensity forecast, and significant changes could occur over the coming hours and days.

As of Sept. 26, authorities have issued the following watches and warnings:

Hurricane Warning

• Anclote River to Mexico Beach, Florida

Hurricane Watch

• Englewood to Anclote River, including Tampa Bay, Florida

Tropical Storm Warning

• The Florida Keys, including Dry Tortugas, Florida

• Flamingo to Anclote River, including Tampa Bay, Florida

• West of Mexico Beach to the Okaloosa/Walton County Line, Florida

• Flamingo, Florida, northward to the Little River Inlet, South Carolina

• Lake Okeechobee, Florida

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

Storm Surge Warning

• Mexico Beach eastward and southward to Flamingo, Florida

• Tampa Bay, Florida

• Charlotte Harbor, Florida

The National Weather Services (NWS) has issued multiple tornado warnings, flash flood warnings, and flood warnings, watches, and advisories across the southeastern US and the Tennessee Valley. As the storm system develops, authorities will likely update and extend the coverage of the weather advisories over the coming hours and days.

Hurricane conditions are expected in the hurricane warning area in the US late Sept. 26. Tropical storm conditions have already begun in the Florida Keys and portions of south Florida, and these conditions are expected to spread northward across the tropical storm warning areas in the southeastern US through early Sept. 27. Strong winds will likely penetrate as far inland as the higher terrain of the southern Appalachians.

The storm is forecast to generate rainfall amounts of 10-20 cm (4-8 inches) across parts of western Cuba, bringing a risk of considerable flooding. Rainfall amounts of 15-30 cm (6-12 inches) with isolated higher totals around 50 cm (20 inches) are expected over parts of the southeastern US and into the southern Appalachian mountains. This rainfall will likely result in catastrophic and potentially life-threatening flash and urban flooding and significant riverine flooding. Numerous landslides are likely in the steep terrain across the southern Appalachians. An increasing risk of tornadoes is likely over parts of northern Florida into southeast Georgia, the Midlands and Low Country of South Carolina, and southern North Carolina late Sept. 26-early Sept. 27.

The combination of a life-threatening storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. If peak surge occurs at the time of high tide, waters could reach up to 4.5-6 meters (15-20 feet) above normal levels between Carrabelle and the Suwannee River in Florida, 3-4.5 meters (10-15 feet) from Apalachicola to Carrabelle and from Suwannee River to Chassahowitzka, and 0.9-3.7 meters (3-12 feet) along other parts of Florida's Gulf Coast. Swells generated by Helene will continue to affect the southern coast of Cuba and the Yucatan Peninsula of Mexico through late Sept. 26-early Sept. 27 and will affect much of Florida and the coasts of Georgia and the Carolinas over the coming days. These swells are likely to cause life-threatening surf and rip current conditions.

Florida Gov. Ron DeSantis declared a state of emergency across 41 of the state's 67 counties Sept. 23 before expanding it to 61 counties Sept. 24. President Joe Biden approved a federal emergency declaration for Florida Sept. 24. States of emergency have also been declared in Georgia, South Carolina, North Carolina, and Virginia. Mandatory and voluntary evacuation orders are in place across dozens of counties in Florida; the latest information regarding evacuation areas can be found here. A curfew is also in effect from sunrise to sunset in Taylor County. Voluntary evacuation orders are also in place for Haywood County in North Carolina. Authorities will likely issue further mandatory and voluntary evacuation orders across affected areas of the southeastern US as the storm approaches. Several schools and universities are closed across parts of Florida and Georgia.

Hundreds of flights have been canceled and delayed across the southeastern US Sept. 26. Tampa International (TPA), St. Pete-Clearwater International (PIE), Peter O. Knight (TPF), Tampa Executive (VDF), and Plant City (PCM) airports have suspended operations Sept. 26; services could resume Sept. 27 once it is safe to do so. Cancelations and delays have also been reported at Southwest Florida International (RSW), Sarasota–Bradenton International (SRQ), Hartsfield–Jackson Atlanta International (ATL), Charlotte Douglas International (CLT), Miami International (MIA), Fort Lauderdale–Hollywood International (FLL), and Orlando International (MCO) airports.

Around 230,000 customers are without power across Artemisa and Pinar del Rio provinces in western Cuba following the passing of the storm system. Widespread flooding has been reported in the region and damage assessments are ongoing in the region as of Sept. 26. 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.