Gulf of Mexico: Hurricane Helene tracking north-northeastward across the Gulf of Mexico as of late Sept. 26 /update 6

Hurricane Helene has strengthened into a Category 4 hurricane and is tracking north-northeastward in the Gulf of Mexico late Sept. 26. As of 23:00 EDT, the system's center of circulation was approximately 70 km (40 miles) southeast of Tallahassee, Florida.

Forecast models indicate that the storm will make landfall over the Big Bend region of Florida in the coming hours. 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 south-central 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 late 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

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, as well as 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 occurring within the hurricane warning area. People are reminded not to venture out into the relative calm when the eye passes over, as hazardous winds will increase very quickly when the eye passes. Tropical storm conditions are occurring in southern and central Florida, and these conditions will continue spreading northward across the tropical storm warning areas in the southeastern US through early Sept. 27. Strong, damaging winds will likely penetrate as far inland as the higher terrain of the southern Appalachians.

The storm is forecast to generate rainfall amounts of 15-30 cm (6-12 inches) with isolated higher totals around 50 cm (20 inches) over parts of the southeastern US 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 significant landslides are likely in the steep terrain across the southern Appalachians. The risk for several tornadoes continues through early Sept. 27 over parts of northern and central Florida, Georgia, South Carolina, and southern North Carolina and will persist across the Carolinas and southern Virginia 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 much of Florida, 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 and for Alabama Sept. 26. 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. More than 1,600 people across Leon County have taken shelter. Authorities have warned Tampa residents that it is too late to evacuate; residents should shelter in place. 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. Authorities have confirmed one fatality in Catawba County, North Carolina, due to a vehicular accident caused by adverse weather early Sept. 26. As of late Sept. 26, more than 885,000 people in Florida, 31,000 people in Georgia, and 12,000 people in North Carolina are without power.

Thousands of flights have been canceled and delayed across the southeastern US since Sept. 25, with the worst affected Tampa, Fort Myers, and Atlanta. Tampa International (TPA), St. Pete-Clearwater International (PIE), Tallahassee International (TLH), Peter O. Knight (TPF), Tampa Executive (VDF), and Plant City (PCM) airports have suspended operations late Sept. 26; services are likely to resume after damage assessments. 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. The Palma Sola Causeway connecting the Bradenton area to Ana Maria Island in Florida is closed.

At the height of this storm, hundreds of thousands of customers were without power across Artemisa and Pinar del Rio provinces in western Cuba; some power has since been restored. Widespread flooding has been reported in the region, and damage assessments have been ongoing since late September 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.