TAMPA, Fla. (WFLA) – Hurricane Helene has been upgraded to a Category 2 hurricane as it moves northward in the Gulf of Mexico. The storm is expected to bring "catastrophic" storm surge and wind after making landfall on Florida's northwestern coast, according to the National Hurricane Center. As of the 11 a.m. update from the National Hurricane Center, Helene is located 255 miles southwest of Tampa and 365 south-southwest of Apalachicola. It is moving at 14 mph with maximum sustained winds at 105 mph. Helene is expected to rapidly intensify into a Category 4 storm and make landfall Thursday night, the National Hurricane Center predicts. (WFLA) The storm is expected to bring "unsurvivable" storm surge of up to 20 feet to the Big Bend area, according to the National Weather Service in Tallahassee, which called it a "nightmare surge scenario." LIVE: Hurricane Helene real-time wobble tracker Jeff Berardelli, the chief meteorologist at Nexstar's WFLA, said residents in the Nature Coast and Big Bend should be heeding all safety and evacuation advice from officials. “You cannot survive 20 feet or even 15 feet of storm surge,” Berardelli said. “If you’re near the water and you know you’re going to flood, especially if you’re in a mobile home, too, you’ve got to go. You cannot take your chances. This is not survivable.” The next update from the National Hurricane Center is at 2 p.m. ET. Hurricane Helene is expected to weaken after making landfall, but its “fast forward speed will allow strong, damaging winds, especially in gusts, to penetrate well inland across the southeastern United States,” including in the southern Appalachian Mountains, the hurricane center said.  'I don’t want anybody to die': Sen. Rick Scott encourages residents to evacuate ahead of Hurricane Helene “Regardless of how strong it is, it is a very large storm," Jack Beven, a senior hurricane specialist at the National Hurricane Center in Miami, said. “It’s going to have impacts that cover a large area.” Hurricane warnings and flash flood warnings extended far beyond the coast up into south-central Georgia. The governors of Florida, Georgia, and the Carolinas have all declared emergencies in their states. Along Florida's Gulf Coast, school districts and multiple universities have canceled classes. Georgia emergency officials recommended all schools, public and private, close on Friday. An update on the storm's track will be provided in the coming hours. Spaghetti Models for Hurricane Helene Helene is forecast to be one of the largest storms in breadth in years to hit the region, said Colorado State University hurricane researcher Phil Klotzbach. He said since 1988, only three Gulf hurricanes were bigger than Helene’s predicted size: 2017’s Irma, 2005’s Wilma and 1995’s Opal. ‘It’s a monsoon’: Video shows Helene battering Cancun Meanwhile, Tropical Storm Isaac formed Wednesday in the Atlantic Ocean and was expected to strengthen as it moves eastward, possibly becoming a hurricane by the end of the week, forecasters said. Isaac was about 690 miles northeast of Bermuda with top sustained winds of 50 mph, according to the National Hurricane Center in Miami. It was moving east at about 12 mph. The National Oceanic and Atmospheric Administration has predicted an above-average Atlantic hurricane season this year because of record-warm ocean temperatures. The Associated Press contributed to this report.