Tallahassee shifted into storm mode Monday as a tropical disturbance threatened to intensify rapidly into a possible major hurricane before hitting the north and eastern Gulf Coast as early as Thursday.

The National Hurricane Center in Miami showed Potential Tropical Cyclone Nine strengthening to a tropical storm by Tuesday morning and a hurricane by Wednesday morning. The initial track, issued Monday morning, showed landfall anywhere from the western Florida Panhandle to the Tampa Bay area.

Joe Worster, meteorologist with the National Weather Service in Tallahassee, said the hurricane was expected to strengthen into a high-end Category 2 storm, on the cusp of a Category 3, as it approaches the Gulf Coast on Thursday morning.

The hurricane will feed off unusually warm Gulf of Mexico waters, with temperatures in the upper 80s, as it strengthens. Worster, quoting the Hurricane Center’s guidance, said there was a 95% chance that the storm’s winds would increase by more than 75 mph over the next 72 hours.

“That’s a pretty good amount,” he said. “What this is showing is that the environment is conducive to to a rapidly intensifying storm.”

The Hurricane Center issued its first tracking map for the storm that is expected to become Helene at 11 a.m. Monday – with Florida's capital city in the bullseye. The storm is forecast to strengthen as it moves north over warm Gulf of Mexico waters. NHC forecasters warned that rapid intensification is possible as is the potential for a major hurricane within 72 hours

The storm's track has become a familiar one for North Floridians as the Big Bend has become something of a hurricane alley. In August, Category 1 Hurricane Debby made landfall near Taylor and Dixie counties in the eastern Big Bend. Its 7 a.m. landfall was just 45 minutes and ten miles shy of where and when Hurricane Idalia made landfall as a Category 3 in late August 2023.

The brewing storm also summoned the specter of Category 5 Hurricane Michael, which formed in a similar location in October 2018 before landfall on Mexico Beach.

The Weather Service said once a center forms, the situation “may evolve quickly” and that residents should prepare now for a hurricane and “significant” impacts.

“There is a potential for significant storm surge, heavy rainfall and flooding and strong winds,” NWS in Tallahassee said. “Impacts could begin as early as Wednesday night and last into Friday.”

The city of Tallahassee and Leon County opened sandbag sites in anticipation of possible severe weather. In a news release, the city said it is closely monitoring the tropics and urged residents to get ready.

“Uncertainty remains around the exact location or magnitude of impacts, which could include downed trees, power outages and localized flooding,” the city said. “City departments are prepared to respond as needed, and residents are encouraged to prepare.”

The city said crews were checking known flooding areas to remove obstructions and steps to prepare for the possibility of outages.

"Electric Utility crews are ready to be deployed, with extra staffing on standby as needed," the city said.

The Weather Prediction Center showed much of the North Florida and South Georgia region with a slight (2 out of 4) for excessive rainfall on Thursday. Rainfall estimates ranged from 4-6 inches to as high as 10 inches.

Worster said changing features in the weather setup have led to variability in the forecast. Models earlier suggested a more western track but since moved more to the east.

“That’s due to some features in the upper level pattern right now changing where it could go,” he said. “So while it might look like there could be a solution right now, that certainly could change over the next few days once we start getting a little more data.”

Worster said interests along the northern Florida Gulf Coast and western Peninsula should pay close attention to forecast. He said residents should get final preparations in place, from gassing up the car and getting cash from an ATM to stocking up on water and nonperishable food.

"Make sure that you have all of your hurricane preparations done," he said.

City of Tallahassee and Leon County open sandbag sites

City sandbag locations:

Jack McLean Community Center, 700 Paul Russell Road

Mike Blankenship Skate Park, 2909 Jackson Bluff Road

Northwood parcel, 1940 N. Monroe Street, near El Jalisco

County sandbag locations:

Leon County’s Northeast Branch Library, 5513 Thomasville Road

Apalachee Regional Park (Solid Waste Management Facility), 7550 Apalachee Parkway

Fred George Park, 3043 Capital Circle NW

Intersection of Oak Ridge Road and Ranchero Road

Fort Braden Community Park, 15000 Blountstown Hwy

Contact Jeff Burlew at jburlew@tallahassee.com or 850-599-2180.