AS Hurricane Irma tore through the Caribbean, a tropical storm in the Atlantic and another in the Gulf of Mexico were upgraded to hurricane status today, the US National Hurricane Centre said.
Hurricane Jose was 1,675km east of the Lesser Antilles in the Atlantic and packing maximum sustained winds of 120km/h, the NHC said.
It was considered a Category One hurricane on the five-level Saffir-Simpson scale.
The NHC said that tropical storm Katia in the southwestern Gulf of Mexico had also become a Category One hurricane.
It said a hurricane watch was in effect for the coast of the Mexican state of Veracruz where heavy rainfall could be expected.
Hurricane Irma, a category five storm further to the west, has roared through Caribbean islands with historic 297km/h winds on its way to a possible devastating hit on Florida.
The strongest Atlantic Ocean hurricane ever measured destroyed homes and flooded streets across a chain of small islands in the northern Caribbean, passing directly over Barbuda and leaving the island of some 1,700 people incommunicado.
This is only the second time since satellites started tracking storms about 40 years ago that one maintained 185 mph winds for more than 24 hours, said Colorado State University meteorology professor Phil Klotzbach.
The other was the massive killer typhoon Haiyan that killed more than 6,000 people in the Philippines in 2013.
"It's a humdinger," he said.
"This thing is a buzzsaw; I'm glad Floridians are taking it very seriously," Klotzbach said. "This is going to be a bad storm. I don't see any way out of it."
Irma has already taken a deadly turn, with at least two people killed and fears of a third.
The French Minister for Overseas Territories confirmed the fatalities as the hurricane charted a course towards Puerto Rico and Florida.
"We're talking about two dead and two seriously injured for now," Annick Girardin told reporters before boarding a plane for the region.
"Obviously the situation can change very quickly."
The dead are two of France's Caribbean territories, St Martin and St Barthelemy.
French President Emmanuel Macron said that while it was too early to come up with a final toll from the rare Category Five storm, it would be "harsh and cruel."
The killer storm is so powerful it has registered as seismic activity on some instruments and packs more power than this year's previous eight storms combined, according to a US scientist.
The NHC warned the "potentially catastrophic" hurricane will bring "life-threatening wind, storm surge and rainfall hazards" to the Virgin Islands and Puerto Rico.
Emergency warnings were in effect across the Bahamas, Dominican Republic, Turks and Caicos with Cuba and Florida likely to be hit later in the week.
IT COMES AS:
• The Governor of the British Virgin Islands ordered a 36-hour curfew for residents.
• Emergency evacuations were ordered for six islands in the Bahamas and are expected in the Florida Keys.
• The White House declared a state of emergency in Florida, the US Virgin Islands and Puerto Rico.
• President Trump said it "looks like it could be something that will be not good. Believe me, not good."
• Billionaire Richard Branson was holed up on his private home on Necker Island.
• Hotels issued warnings to guests who described "apocalyptic" noises.
• Storm surges six metres above normal tide levels are expected.
• Puerto Rico residents prepare to be without electricity for four-six months.
• Colorado State University professor Phil Klotzbach warns "the Leeward Islands are going to get destroyed."
• Tropical storm Jose is expected to become a hurricane in 36-48 hours.
'MAY GOD PROTECT US ALL'
The Red Cross said it is bracing for a "major humanitarian response" to the storm made worse by the severe rainfall and isolation of the islands.
The agency's regional director Walter Cottee said: "We are anticipating major impacts on a number of islands, and we are preparing to respond to needs that may arise."
"One of the main challenges is going to be logistical, given the isolation of some the islands. We need to ensure a reliable channel for relief efforts in the aftermath of the hurricane."
France's minister for overseas territories, Annick Girardin, said the office had likely underestimated the storm's power as it hurtled towards the French-run territory of St Barths. It has already "blown the roofs" off buildings and is expected to hit the larger French islands of Guadeloupe and Martinique.
Antigua resident Kazia phoned a local radio station to say she was "praying to God" while being hunkered down with no power. Visitors to the island were turned away from the closed airport on Tuesday with the words: "May God protect us all."
London PR expert Alex Woolfall, who specialises in crisis management, tweeted that he could hear "thunderous sonic boom noises outside" from his hotel in St Martin.
CARE Australia's emergency teams said they were working to prepare clean drinking water, food supplies and shelter for residents in Haiti which is still recovering from Hurricane Matthew one year ago.
Country director Karl Paul said it could be a "monster" storm when Irma hits on Thursday.
"Irma's biggest threat is flooding and mudslides in addition to damage from the hurricane's heavy winds and rain. We're also concerned the anticipated flooding could contaminate the water supplies," he said.
Video and images posted on social media show the strength of the storm as it moves across the Caribbean and towards the Gulf of Mexico.
BRANSON 'RETREATS TO WINE CELLAR'
Virgin boss Richard Branson wrote from his private Necker Island resort that the atmosphere was "eerie but beautiful" as he waited for the storm to hit.
"All of us slept together in two rooms. I haven't had a sleepover quite like it since I was a kid. Strangely, it's a privilege to experience what is turning into possibly the strongest storm ever with such a great group of young people," he wrote.
"We were listening to the parrots in their boxes in the next room chattering away. Watching the tortoises congregating together, as if they sense what is coming our way."
"We are expecting to get the full force of the hurricane in around five hours' time, when we will retreat to a concrete wine cellar under the Great House. Knowing our wonderful team as I do, I suspect there will be little wine left in the cellar when we all emerge."
'NO REST FOR THE WEARY'
In Florida residents endured eight-hour waits to stock up on bottled water and many bought supplies to reinforce their homes and businesses. Lines at petrol stations were 50 cars long in Fort Lauderdale with workers running out of petrol in some places.
President Trump said his team was watching the Hurricane closely following the destruction from Hurricane Harvey that hit Texas and Louisiana last week.
"No rest for the weary!" he wrote on Twitter as the House of Representatives votes on a US$7.9 billion relief bill for Harvey.
He later said the hurricane "looks like it could be something that will be not good. Believe me, not good."
Florida Governor Rick Scott urged people to stock up on supplies, register to volunteer and not be complacent during the storm.
The Australian government has warned those travelling to the region to follow local media reports and expect high winds and storm surges. For the latest advice, check the SmartTraveller website.
The strength of the hurricane is partly due to the fact that water in the area was 1.8 degrees warmer than normal, according to Jeff Masters, meteorology director of the private forecasting service Weather Underground.
He said hurricanes need water around 26 degrees to form and that was currently about 80 metres deep.