MIAMI _ Florida raced to get ready for a major hurricane Monday after Michael rapidly intensified overnight, threatening to slam the northeastern Gulf Coast Wednesday as a powerful Category 3 storm.
Sustained winds had increased to 80 mph as the storm churned past Cuba's west coast, but could build to 120 mph over the next 36 hours, National Hurricane Center forecasters said Monday evening. Michael is likely to continue strengthening Tuesday and could quickly deepen as it enters the southeastern Gulf of Mexico and crosses very warm waters, forecasters said.
As conditions began to look more dire Monday, Florida braced for what could be the worst storm to hit the Panhandle since Hurricane Ivan in 2004.
In a briefing, Florida Gov. Rick Scott urged residents to pay careful attention to weather updates and heed evacuation orders. He asked President Donald Trump to declare an emergency for the state in advance of Michael's arrival and called more than 1,200 members of the National Guard to duty. Another 4,000 were placed on standby.
"Everybody take this seriously," he said. "You always prepare for the worst. This is a massive storm. We've not seen anything like it in the Panhandle."
Mandatory evacuations were ordered along parts of the coast expected to see the fiercest winds and highest storm surge, including Wakulla, Franklin, Gulf and Bay counties. Voluntary evacuations were ordered for Santa Rosa and Citrus counties.
Scott also expanded a state of emergency to include 35 counties in the storm's path. In Bay County, emergency operations officials said bridges are likely to close and visitors should make plans immediately to leave. Florida State University also announced that it would close just after midnight Tuesday. Public schools also began closing across the Panhandle.
Hurricane and tropical storm watches covered much of the Gulf Coast, with forecasters warning that Michael's storm surge could be life-threatening. Waters from Indian Pass to Crystal River could rise eight to 12 feet above normal, they said.
"Some of these rivers can even flow backward," National Hurricane Center Direct Ken Graham said. "Storm surge is taking these areas that normally drain out and pushing the water in."
Unlike the pounding rain that caused Carolina rivers to crest and flood communities during a slow-moving Hurricane Florence last month, Michael's storm surge alone could overwhelm the low-lying coast carved by bays and inlets _ although heavy rain is also forecast. The curve of the coast makes the area particularly vulnerable, acting like a funnel to trap water as Michael plows across the shallow continental shelf.
"It collects the storm surge like a catcher's mitt. It gobbles it up and worsens it," said Jamie Rhome, chief of the hurricane center's storm surge unit.
And unlike the deeper waters off the Atlantic coast, the shallow shelf means water has nowhere to go but onshore.
"There is no storm surge out in the deep ocean because the water can go back down. It has plenty of room to spread out," Rhome said. "But when you have a wide continental shelf, the water's got nowhere to go."
Hurricane force winds extend about 30 miles from the compact storm's center, with tropical storm force winds reaching 175 miles. Michael could also dump up to 8 inches of rain, with 12 inches possible in some areas along the northeastern Gulf Coast, raising the risk of flooding. So far, however, the storm is expected to quickly depart and not linger once it makes landfall.
While Michael is forecast to land far from South Florida, squally weather through Wednesday could still bring gusty winds and rain, the National Weather Service's Miami office said. The Florida Keys could get 2 to 4 inches.
Forecasters say the storm should speed up Tuesday night, but models differ on how fast it moves across the northern Gulf of Mexico. They gave it a 55 percent to 60 percent chance of rapidly intensifying over the next 24 hours, but expect strengthening to slow after that as wind shear picks up. Wind speed should drop slightly just before landfall, although there's a chance part of Michael stays over the Gulf and continues to generate tropical storm conditions, they said.
By midday Monday, hurricane-force wind bands had reached Cuba's sparsely populated Guanahacabibes Peninsula, much of which lies in a protected wildlife area known for pristine beaches, reefs and the second largest green turtle breeding population on the island. Home videos posted on Cuban media showed water washing over streets and a thicket of downed branches and small trees in Pinar del Rio province.
Cuban meteorologist Jose Rubiera said wind gusts of more than 80 miles per hour were reported in Cabo de San Antonio, where 5.8 inches of rain fell in a six-hour period.
Widespread flooding was reported along the coast, with surge washing inland more than 160 feet in parts of the southern coast in the Pinar del Rio province.
In South Florida, a seasonal king tide is expected to worsen flooding on top of the squally weather, the National Weather Service said. Winds could reach between 30 and 45 mph, with a chance of isolated tornadoes. Street flooding is possible and low-lying areas may also see rising water at high tides about 8:40 a.m. and again at 9 p.m.
While October tends to be the worst month for hurricanes in Florida, Michael's sudden transformation surprised even seasoned meteorologists.
"If someone had asked me five days ago, 'Hey I want to go to Tallahassee, am I going to get hit by a hurricane?' I would have said sure, you're good to go," said Colorado State University meteorlogist Phil Klotzbach. "Florence felt like it was out there forever, but this storm came out of nowhere."
