Miami, which was on track for a direct hit from Hurricane Irma, was thrown a lifeline on Saturday as the storm's path veered west.
Irma was downgraded from a Category 4 to a Category 3 storm on Saturday mid-morning as it hovered over Cuba but officials warned that it could regain strength over the course of the weekend.
Irma is expected to move up the southwest coast on Sunday, bringing with it 130mph winds and life threatening rain after battering Cuba on Saturday.
Miami is still under an evacuation order and officials are warning residents not to return to their homes in light of the news that Irma is moving west because it is still at risk of severe storm surge.
Irma is so powerful that no matter where it hits and even before it does, the entire southern section of the state is at risk of storm surge, deadly wind and rain.
More than 5million people have been evacuated in anticipation of it and 50,000 people are in shelters across the state.
On Saturday morning, Governor Rick Scott, who has been pleading with residents for days to leave evacuation zones before Irma hits, said : 'This is a catastrophic storm. We have never seen this before. The storm is bigger than our state.
He said he had called up 7,000 National Guard troops to help deal with the catastrophe. People in Florida are being told to prepare three days worth of food and water to ride out the zone.
In the largest evacuation effort in US history, millions of people in the Sunshine State and in parts of Georgia have been told to leave their home before Irma strikes on Sunday afternoon.
All of the airports in southeast Florida are now closed and anyone who is still there is being told to leave urgently or take refuge in one of the shelters being set up.
In Miami, officials admitted they were 'rewriting the book' as they went along to try to prepare for Irma. Evacuees who have been able to get to a shelter compared the cramped conditions inside to Guantanamo Bay.
Some people are being turned away as high schools and other public spaces reach capacity.
As of Friday night, only 21 of the 42 planned shelters in Miami Dade County, which takes in a huge swathe of the city, had been announced.
The monstrous hurricane has already claimed 24 lives in the Caribbean and wiped out entire small islands.
Cuba and The Bahamas were battered by the storm on Friday night and Saturday during the day. Irma made landfall on the island nation at around 11.10pm on Friday as a Category 5 hurricane. Its eye hovered over the northwest tip on Saturday.
The winds were ferocious, reaching 160mph in parts of The Bahamas and destroying a wind measuring device in Cuba.
The outer bands of the hurricane have already reached the U.S., with south Florida and the Keys experiencing increased rain and wind speeds.
The storm was first downgraded from a Category 5 to a Category 4 earlier on Friday morning. But on Friday night, it was again made a Category 5 storm before being relegated back to 4 early this morning.
CNN's Patrick Oppman live tweeted about the terrifying conditions on Friday night. On Saturday, once the storm had downgraded slightly, he went on the air to try to deliver his broadcast.
It gave a frightening picture of the reality on the island which is still largely made up of 1950s architecture and infrastrucure.
Oppman struggled to keep his rain coat out of his face and had to retreat into a cupboard of the house where he and his team were filming.
Government officials along with the National Hurricane Center have cautioned that Irma is 'extremely dangerous' with maximum sustained winds of 155 mph. That's strong enough to bring down power poles, uproot trees and rip the roofs off of homes.
Tampa's Mayor Bob Buckhorn spoke to CNN after the new forecast was revealed.
Irma will strike Tampa on Monday, bringing heavy rain and wind for several hours. The real concern is the storm surge the rain will trigger.
Buckhorn warned residents in evacuation zones to get out now before the winds grow too strong.
'There will be people who think they can ride this out. We hope they will be OK.
In a sinister sign-off, he added: 'We never expected a storm of this magntitude.
The forecasts show that dangerous storm surges could begin as early as Saturday night before the storm even hits Florida.
It's then expected to track directly up the state, crossing the state line into Georgia early next week.
Virginia's Gov. Terry McAuliffe declared a state of emergency to help the state get ahead of any damage caused by Hurricane Irma.
The declaration also allows Virginia to provide assistance to other states who will be impacted by the storm.
Virginia may face possible flooding, high winds and storm surge as a result of Hurricane Irma.
'It is unfortunate that just as our nation has begun the process to repair the catastrophic damage from Hurricane Harvey, that we are faced with another extreme storm,' McAuliffe said on Friday.
'However, if there is one lesson we can take from the tragic events that occurred in Texas, it is that we must redouble our preparation efforts.
A state of emergency allows the commonwealth to mobilize resources, including the Virginia National Guard, and pre-position people and equipment to assist in storm response and recovery efforts.
All Virginians must prepare in advance for the potential impacts of this historic hurricane.
Miami-Dade County: Mandatory evacuations for all of Zone A, all of Zone B, and portions of Zone C.
Lake Okeechobee: Florida officials want residents to evacuate the area directly south of Lake Okeechobee. A voluntary evacuation was issued for the cities of South Bay, Lake Harbor, Pahokee, Moore Haven, Clewiston, Belle Glade and Canal Point. Mandatory evacuations for these cities will be put into effect Saturday morning.
Glades County: Residents in zone A must evacuate by noon Friday. Everyone living in an RV park, mobile home or a building constructed before 1992 must also evacuate.
Citrus County: Mandatory evacuation for residents west of U.S. Highway 19, those living one and a half miles east of U.S. 19, Crystal River residents, residents living in low-lying areas, and residents living in mobile homes, manufactured homes and all unsafe structures.
Hernando County: Mandatory evacuation for coastal zones A and B and mobile homes countywide.
Hendry County: Mandatory evaciation for Clewiston, Hookers Point, Harlem, Flaghole, Montura Ranch Estates, and communities within the Mid-County MSBU which incudes Ladeca, Pioneer Plantation and Leon-Dennis Subdivision. resiednts in no-slab build homes, mobile homes trailers and RVs are under voluntary evacuation.
Sarasota County: People living in evacuation Zone A are to leave between 2pm Friday and 8pm Saturday.
Pasco County: Mandatory evacuation for residents who live west of U.S. 19, north of Fox Hollow, west of Little Rd and special needs residents throughout the county.
Volusia County: Voluntary evacuations of residents in beachside, low-lying areas and in RV, mobile or manufactured homes.
Hillsborough County: Voluntary evacuations for residents in Zone A who are registered for special needs shelters staring 8am Friday.
Highlands County: Voluntary evacuation for residents who live in low-lying areas and manufactured mobile homes.
Taylor County: Voluntary evacuation for residents who live in low-lying areas and manufactured mobile homes.
Alachua County: Voluntary evacuation for residents who live in low-lying areas and manufactured mobile homes.
Hardee County: Voluntary evacuation for residents who live in low-lying areas and manufactured mobile homes.
Lake County: Voluntary evacuation for residents who live in low-lying areas and manufactured mobile homes.
Georgia ordered the evacuation of the state's coastal areas. It applies to all areas east of Interstate 95, including the city of Savannah.
Hurricane Irma killed at least 24 people in the Caribbean and left thousands homeless as it devastated small islands in its path. And it's already proved deadly in the U.S. A man installing hurricane shutters on his Florida home fell off a ladder and died on Thursday.
The National Hurricane Center issued hurricane warnings for the Keys and parts of South Florida and Lake Okeechobee. It added a storm surge warning and extended watch areas wrapping around much of the peninsula.
For Irma, forecasters predicted a storm surge of 6 to 12 feet above ground level along Florida's southwest coast and in the Keys. As much as a foot of rain could fall across the state, with isolated spots receiving 20 inches.
Scott has been pleading with his citizens all week to evacuate if they are ordered to, and to prepare - no matter the direction of the storm.
Social workers and police officers gave Miami's estimated 1,100 homeless people a stark choice on Friday: Come willingly to a storm shelter, or be held against their will for a mental health evaluation.
Officials - backed by a psychiatrist and observed by an Associated Press team - rolled through chillingly empty downtown streets as dawn broke over Biscayne Bay, searching for reluctant stragglers sleeping in waterfront parks.
'We're going out and every single homeless person who is unwilling to come off the street, we are likely going to involuntarily Baker Act them,' said Ron Book, chairman of the Miami-Dade Homeless Trust.
Invoking the 'Baker Act' - a law that enables authorities to institutionalize patients who present a danger to themselves or others - is not something law enforcement does lightly, but officers detained at least six people by Friday afternoon. Under the law, they can be held up to 72 hours before the state would have to go to court to prolong their detention.
Book's group was working closely with police, who acknowledged that the effort is unusual: Officials said it is the first time Miami has invoked the law for hurricane preparedness.
About 70 people willingly climbed into white vans and police squad cars Friday, joining others who already arrived at shelters.
About 600 others were thought to remain outside somewhere, exposed to the storm, despite mandatory evacuation orders for more than 660,000 people in areas that include downtown Miami and coastal areas throughout the county.
Scott has also ordered all state offices, schools, colleges and universities to close from Friday until Monday to free up space for evacuation shelters and staging. Most school districts and universities had already voluntarily agreed to close due to the looming arrival of Hurricane Irma over the weekend - but many school districts and colleges in north central and northwest Florida had remained open.
'Floridians are strong and resilient. In times like this we band together and help each other. We will continue working around the clock to help you prepare and after the storm we'll be here to lift each other up and recover. We will make it through this together. Florida is an amazing melting pot of loving people,' Scott said.
Gas shortages and gridlock plagued the evacuations, turning normally simple trips into tests of will. Interstates 75 and 95 north were bumper-to-bumper, while very few cars and tractor-trailers drove on the south lanes.
Floridians fleeing Hurricane Irma have turned Atlanta's freeways into a ribbon of red neon brake lights, with traffic in some spots barely moving.
Thousands of the evacuees have been funneled to the city, since so many of them are heading north on Interstate 75 straight to Atlanta.
Some ended up at Atlanta Motor Speedway, which opened its vast camp grounds to anyone trying to escape Irma.
It took 21 hours for Suzanne Pallot of Miami to reach Atlanta Thursday, in an SUV packed with four other people, their luggage and two cats.
After a night at a relative's house, she heard weather forecasts predicting tropical storm force winds for Atlanta on Monday. So the group decided Friday to keep moving, this time to Memphis, Tennessee.
Manny Zuniga left his home in Miami at midnight Thursday, planning to drive through the night to avoid the traffic gridlock that he'd seen on television. It still took him 12 hours to get 230 miles to Orlando - a trip that normally takes four hours. Zuniga is headed for a relative's house in Arkansas with his wife, two children, two dogs and a ferret.
Mari and Neal Michaud loaded their two children and dog into their small sport-utility vehicle and left their home near Cocoa Beach about 10am, bound for an impromptu vacation in Washington, D.C.
Using a phone app and calls to search for fuel along the way, they finally arrived at a convenience store that had gasoline nearly five hours later. They said the 60-mile trip up Interstate 95 should have taken an hour.
Noel Marsden said he, his girlfriend, her son and their dog left Pembroke Pines north of Miami with plans to ride out Irma in Savannah, only to find the city was also shutting down because of Irma. Marsden isn't sure where they'll all end up.
'I've got a buddy in Atlanta and a buddy in Charlotte. We'll wind up one of those two places because there are not hotels, I can tell you that,' he said.
The governor said people fleeing could drive slowly in the shoulder lane on highways. He hasn't reversed the southbound lanes because he said they were needed to deliver gas and supplies.
The Homeland Security Department is temporarily waiving federal restrictions on foreign ships' transportation of cargo in order to help distribute fuel to states and territories affected by hurricanes Harvey and Irma.
In a statement Friday, acting Homeland Security Secretary Elaine Duke said, 'This is a precautionary measure to ensure we have enough fuel to support lifesaving efforts, respond to the storm, and restore critical services and critical infrastructure.' The seven-day waiver specifically affects shipments of refined products, such as gasoline, in hurricane-affected areas.
The Jones Act prohibits such shipments between U.S. points aboard foreign vessels. The last such waiver was in December 2012, for petroleum products delivered after Hurricane Sandy.
Airline seats out of Florida were in short supply as well but American, United and Delta all said Thursday that they were adding extra flights in the next couple days.
Shockingly enough, an armed man caused extra panic and delays at Miami airport on Thursday night after he was shot by police - prompting the evacuation of an entire terminal.
Officials across Florida, meanwhile, opened shelters for people who chose not to leave town. Florida's emergency management division says thousands of people are already huddling in shelters ahead of Hurricane Irma. Most of the evacuees are gathered in shelters in Broward and Miami-Dade counties, where catastrophic Category 4 winds are expected to hit this weekend.
Miami Mayor Carlos Gimenez said 23,000 people are currently in shelters in the county ahead of Hurricane Irma. He added that the county has the capacity to house 100,000 in shelters during this emergency.
Miami-Dade has 43 shelters operating, seven are at capacity or closed, the mayor said tonight at a news conference.
Evacuation orders are multiplying by the hour in Florida. Currently the entire southern tip of Florida is under evacuation, and those orders continue county by county almost all the way up the east coast.
Several small communities around Lake Okeechobee in the south-central part of Florida were added to the evacuation list because the lake may overflow, the governor said - but he added that engineers expect the protective dike around the lake to hold up.
Some residents in downtown Miami were also advised to leave, if they leave near one of the city's two dozen construction cranes.
Construction sites across Irma's potential path in Florida are being locked down to prevent building materials, tools and debris from becoming flying missiles in hurricane winds.
The horizontal arms of the tall tower cranes, however, will remain loose despite the potential danger of collapse. City officials say they cannot be tied down or moved. Miami officials say it would take two weeks to move the cranes.
South Carolina's Gov. Henry McMaster ordered mandatory evacuations of eight barrier islands in Beaufort, Jasper and Colleton counties on Friday.
The evacuations begin at 10am on Saturday, as some of those areas are still recovering from Hurricane Matthew, which skimmed along the South Carolina coast less than a year ago.
The largest barrier island involved in the evacuation is Hilton Head, which has more than 40,000 permanent residents.
On Thursday, the governor of Georgia also ordered the evacuation of the state's coastal areas, including the large city of Savannah - about 540,000 people. However, just where the storm will enter Georgia is to be determined. Forecasts show it could enter the state Monday anywhere from the Atlantic coast to the Alabama state line. The last time Georgia was struck by a hurricane of force Category 3 or higher happened in 1898.
As additional evacuations continue to be announced, Irma could potentially create one of the largest mass exoduses in the country's history.
Forecasters warn the storm could hit anywhere from Florida to North Carolina over the next few days. The most severe impacts will be felt on the eastern side of Florida, including Miami, West Palm Beach, Melbourne, Daytona Beach and Jacksonville.
AccuWeather founder, Dr Joel N Myers, said there was no way the U.S. was going to avoid another catastrophic weather event.
According to Credit Suisse, the storm has the potential to do $125billion worth of damage.
NASA has secured Kennedy Space Center and SpaceX launched an unmanned rocket for an experimental flight. Kennedy closed its doors to all nonessential staff and a crew of about 120 people will ride out the storm on site.
Most of the critical buildings at Kennedy are designed to withstand gusts of up to 135 mph. Irma's wind could exceed that if it reaches Cape Canaveral as a Category 5 storm.
Irma poses a bigger menace to power supplies in Florida than Hurricane Harvey did in Texas because Irma is packing near 200 mile-per-hour winds that could down power lines, close nuclear plants and threats to leave millions of homes and businesses in the dark for weeks.
Florida Power & Light's Turkey Point and St. Lucie plants, which can supply power to almost two million homes, are under threat.
The company, a subsidiary of NextEra Energy Inc, is watching the weather and would adjust any plans as necessary.
It can take more than 24 hours to shut down a reactor, so the decision will have to be made well in advance.
But bosses are confident the power plants can weather the 185mph storm, as they both have a track record of surviving hurricanes.
The last major hurricane - a storm with winds of at least 111 mph - to hit Florida was Wilma in 2005. Its eye cut through the state's southern third as it packed winds of 120 mph; five people died. Andrew slammed into Florida as a Category 5 storm in 1992 and at the time was the costliest hurricane in U.S. history with damages of $26.5 billion.
With winds that peaked at 185 mph, Irma was the most powerful hurricane ever recorded in the Atlantic.
In a video posted to Facebook, the president urged those in Irma's path to be vigilant and heed the recommendations of all government officials.
Trump said his administration is doing all it can to help with disaster preparations, and the U.S. 'stands united' to address the storm.
After struggling to hear the shouted questions from reporters, he said that while the storm is 'a really bad one,' the U.S. is prepared for the dangerous major hurricane heading toward Florida.
Trump's exclusive Mar-a-Lago resort in Palm Beach - the unofficial Southern White House - sits in the path of the storm.
US Air Force Reserve weather officer Maj. Jeremy DeHart flew through the eye of Irma at 10,000 feet Wednesday and through Hurricane Harvey just before it hit Texas last month.
'Spectacular is the word that keeps coming to mind. Pictures don't do it justice. Satellite images can't do it justice,' DeHart said.
The five living former U.S. presidents said Thursday they would team up to create the 'One America Appeal' to raise money for storm recovery as Texas and Louisiana seek to regroup from Harvey and Florida and the East Coast brace for Hurricane Irma.
The hurricane recovery effort was announced by former presidents Barack Obama, George W. Bush, Bill Clinton, George H.W. Bush and Jimmy Carter.
As people along the East Coast anxiously watched the behemoth, Irma battered the northern Caribbean, killing at least 24 people and leaving thousands homeless after destroying buildings and uprooting trees.
Nine deaths were reported in the French Caribbean (St Martin and St Barthelemy), three in Puerto Rico, four in the U.S. Virgin Islands, four in the British Virgin Islands, two on the Dutch side of St. Maarten, one on Barbuda and one on Anguilla.
Waves as high as 20 feet were expected in the Turks and Caicos. Communications went down as the storm slammed into the islands, and the extent of the devastation was unclear.
Irma rolled past the Dominican Republic and Haiti on Thursday and spun along the northern coast of Cuba on Friday morning before it hit the island.
Thousands of tourists were evacuated from low-lying keys off the Cuban coast Thursday in anticipation of 20-foot storm surges. Buses loaded with tourists began streaming out of Santa Maria, Cayo Coco, Cayo Guillermo and other keys dotted with all-inclusive resorts.
All residents of the area were under mandatory evacuation orders from the Cuban government, which was moving tens of thousands of people from vulnerable coastline.
French, British and Dutch military authorities rushed aid to a devastated string of Caribbean islands. Warships and planes were sent with food, water and troops after the hurricane smashed homes, schools and roads, laying waste to some of the world's most beautiful and exclusive tourist destinations.
The first islands hit by the storm were scenes of terrible destruction.
The cafes and clothing shops of the picturesque seaside village of Marigot were submerged in brown floodwaters. The toll could rise because rescue teams had yet to get a complete look at the damage.
Looting was reported in St. Martin. Annick Girardin, minister for France's overseas territories, described on BFM television Friday 'scenes of pillaging' of televisions as well as food and water. She lamented 'how people can take advantage of the distress of others' and said it's essential for police to restore order and ensure urgent care for victims.
The U.S. Consulate General in Curacao said it believes about 6,000 Americans are stranded on St. Martin. It said it was working with the U.S. and other governments to try to figure out how to get the Americans off the island either by air or boat. Frantic Americans were calling home to relatives to try to get them off the island ahead of Hurricane Jose.
The hospital on St. Thomas was destroyed and dozens of patients were being evacuated to St. Croix and Puerto Rico by the U.S. Coast Guard. Local official said a U.S. Navy hospital ship was arriving as early as Friday to care for unknown numbers of injured and two Air Force C-130s transport planes were bringing in food and water.
Power lines and towers were toppled, leaves were stripped off plants and trees, a water and sewage treatment plants was heavily damaged and the harbor was in ruins, along with hundreds of homes and dozens of businesses. Gov. Kenneth Mapp imposed a 6pm curfew.
Irma also slammed the French island of St. Barts, tearing off roofs and knocking out electricity in the high-end tourist destination.
French Interior Minister Gerard Collomb said 100,000 food rations were sent to St. Barts and St. Martin, the equivalent of four days of supplies.
'There is no power, no gasoline, no running water. Houses are under water, cars are floating through the streets, inhabitants are sitting in the dark in ruined houses and are cut off from the outside world,' he said.
Big waves smashed a dozen homes into rubble in the Dominican fishing community of Nagua, but work crews said all the residents had left before the storm. Officials said 11,200 people in all had evacuated vulnerable areas, while 55,000 soldiers had been deployed to help the cleanup.
In Haiti, two people were injured by a falling tree, a national roadway was blocked by debris and roofs were torn from houses along the northern coast but there were no immediate reports of deaths. Officials warned that could change as Irma continued to lash Haiti, where deforested hillsides are prone to devastating mudslides that have wiped out entire neighborhoods of precariously built homes in flood zones.
'We are vulnerable. We don't have any equipment to help the population,' Josue Alusma, mayor of the northern city of Port de Paix, said on Radio Zenith FM.
French President Emmanuel Macron's office said he would go to the islands as soon as the weather permits it.
On Barbuda, nearly every building was damaged when the hurricane's core crossed almost directly over the island early Wednesday. About 60 percent of its roughly 1,400 residents were left homeless, Antigua and Barbuda Prime Minister Gaston Browne said.
Brian McNoldy, a hurricane researcher at the University of Miami, said Irma could easily prove to be the costliest storm in U.S. history.
'Take it seriously, because this is the real deal,' said Maj. Jeremy DeHart, a U.S. Air Force Reserve weather officer who flew through the eye of Irma at 10,000 feet.
Farther out in the Atlantic, Hurricane Jose, a Category 4 storm with 125 mph winds, posed a potential threat for Saturday to some of the same islands ravaged by Irma.