Tropical storm Idalia is crossing into Georgia, bringing powerful winds and potentially life-threatening conditions
President Joe Biden warns Idalia, which hit Florida as a Category 3 hurricane, is "still very dangerous"
More than 440,000 people are without power in Florida and Georgia
There are no confirmed fatalities from the storm – however Florida Highway Patrol has reported the deaths of two drivers in crashes caused by rainy conditions
Some areas of Florida have been flooded, and the National Hurricane Center warns storm surge still threatens coastal areas
The head of the Federal Emergency Management Agency says Idalia is the strongest storm to hit this part of Florida in more than 100 years
You can watch live pictures from around Florida by clicking the play button at the top of this page
Idalia is now a Category 2 hurricane.
The National Hurricane Center has just upgraded the storm classification.
It says a life-threatening storm surge and hurricane conditions are expected along portions of the Gulf Coast of Florida tonight and Wednesday.
A Category 2 hurricane travels with winds of up to 110 mph (177 km/h) that can cause extensive damage.
Franz Strasser
Reporting from Washington DC
Taking a look at all hurricanes making landfall in the US since 1911, you can see that the number has gone from 12 in the 1970s to 19 in the 2000s and 2010s.
But it has not been dramatically higher recently than the 20th century average of roughly 17 per decade.
What is happening more, experts say, is that warming waters are leading to more hurricanes over the Atlantic strengthening to major hurricanes, those Category 3 and higher. And not all of them have to make landfall to have an impact on US residents living in coastal areas.
Image source, .
Image source, ReutersMost of Florida's 21 million residents, along with tens of millions of others in Georgia and South Carolina, are under warnings of some kind in anticipation of Hurricane Idalia.
These are pretty sizeable figures to comprehend. But, while we wait for the storm to hit, the majority of information we have is based on just that: numbers.
And while some are certain and others approximate, it is important to get our heads round those key figures. Let's break them down:
Image source, EPAAt the White House, President Biden has said he assured Florida Governor Ron DeSantis in a phone call last night that his state will get whatever help it needs.
“We’re worried about the ocean surge,” Biden told reporters ahead of a bilateral meeting with Costa Rica's president.
He said that his team was monitoring Idalia's path "hour to hour".
“We’re there as long as it takes, and we’ll make sure they have everything they need,” he added.
It marks a rare conversation between Biden, a Democrat, and DeSantis, a Republican who is in the 2024 race for president.
Mike Wendling
Reporting from Tampa, Florida
Image source, Hillsborough CountyTampa's evacuation zones - the area in red is most at risk from flooding and storm surge
The word “evacuation” brings to mind long lines of traffic and people struggling to move hundreds of miles inland.
But that’s not the situation here in Tampa, where large parts of this metro area of three million people are out of reach of Idalia’s potentially deadly storm surge.
The city is divided into five coloured zones, but only Zone A, shown in red above and comprising low-lying areas closest to the water, is under a mandatory evacuation order. That said, others are being encouraged to seek shelter, particularly if they live in mobile homes.
“You don’t always know what’s safe or not, because Tampa’s so big,” said Chanel Jay, who was hunkering down in a shelter about a 10 minute drive away from her home.
Right now the worst winds and storm surges are forecast to hit sparsely populated areas further to the north.
But things can change quickly and Chanel, who is facing her second hurricane since moving from Pennsylvania, says she isn’t taking any chances.
“Florida weather has a mind of its own,” she says.
The Governor of South Carolina, Henry McMaster, has declared a state of emergency.
He says the decision was made out of "an abundance of caution" to make sure they were ready for any flooding, and could respond quickly if the forecast worsens.
More than 500 flights within the US have been cancelled today, according to the FlightAware flight tracking database.
Of those, 379 flights arriving or departing from Tampa Airport account for the vast majority of the cancellations.
The Tampa Bay area is expected to suffer significant impacts once Hurricane Idalia makes landfall in Florida, and the airport has already suspended its commercial operations.
Nearly 2,000 US flights have also been delayed since this morning.
Image source, ReutersWorkers fortify power lines in Clearwater
Image source, ReutersA man places plywood barricades ahead of the hurricane's arrival in Cedar Key
Image source, ReutersHome Depot employee Sharon Walsh fills a cart with cases of water while moving them to the front door in Ocala
Image source, ReutersMen install barriers outside the Marriott hotel ahead of Hurricane Idalia in Clearwater Beach
Mike Wendling
Reporting from Tampa, Florida
We’re seeing the first signs of the storm here on Florida’s west coast. In the last few minutes rain has just started to fall on a shelter for disabled and special needs residents of Tampa.
Staying dry inside is Susan Bush, a lifelong local who lives in a mobile home and is recovering from a knee replacement. Susan is 75 and has lost track of exactly how many storms she’s been through.
“Normally I wouldn’t leave home, but my neighbour convinced me this one could be serious,” she says.
Last year when Hurricane Ian tore through Florida she found shelter at a friend’s house. There was a deluge of debris and they lost power for four days, she says, but Susan’s hoping Idalia won’t be that bad.
“With luck I’ll only be here for a day or so,” she says.
Image source, .Richard Gray
Editor, BBC Future
This year's hurricane season will be an epic tug of war between competing climate patterns in the Pacific and Atlantic Oceans.
The tropical Pacific Ocean has entered an El Niño phase, a warming of the surface waters in the central and eastern Pacific. This drives atmospheric conditions that increase the wind shear (the difference between the speed and direction of winds at various altitudes) above the Atlantic. High wind shear can prevent hurricanes from forming, causing them to topple over and collapse.
But hurricanes also rely upon the heat given off from the surface of the ocean for energy. This year, sea surface temperatures globally have been breaking records, and temperatures have been particularly high in the North Atlantic. This has led to the US National Oceanic and Atmospheric Administration (NOAA) predicting that the 2023 hurricane season will be more active than normal, external in terms of the number of storms and their intensity.
Scientists at the NOAA also recently identified another factor that could play a role – El Niño's little brother, known as Atlantic Niño. This cycle, which involves the warming of the tropical water off the west coast of Africa, fuels some of the most powerful hurricanes, which begin as storms in the Cape Verde archipelago. This year's Atlantic Niño appears to be in a "neutral phase" at the moment, so it is not likely to have much effect on this hurricane season unless it changes phase.
Find out more in this article by my colleague India Bourke.
Ron DeSantis: Run from the water, hide from the wind
If you're just joining us, or are in need of a recap, here are the key points covered during the latest update on Hurricane Idalia.
DeSantis takes the podium again. He tells the conference that he is in the process of requesting a major disaster declaration from the federal government.
"It's our belief that that will be approved based on our conversations with FEMA."
DeSantis says this should help with the repairs and clean-up efforts following the storm.
The press conference is now finished.
We expect to hear further updates throughout the day and evening as the hurricane approaches Florida's coast.
Jimmy Patronis, Florida's chief financial officer, urges residents to be on the lookout for "predators who will pre-stage outside these affected areas" and offer services before and after the storm.
Such services may include tree removal and power restoration, he says.
But their services will not be eligible for any restitution or reimbursement claims from insurance companies, so do not sign anything, he warns.
"If you feel comfortable giving a total stranger who approaches you on your doorstep money, you may as well be setting it on fire," Patronis says.
"Use some common sense. If it's too good to be true, it usually is."
DeSantis says his state is prepared for the hurricane to make landfall.
More than one million gallons of fuel have been placed on standby.
In addition, hundreds of urban search and rescue personnel, as well as 5,500 members of Florida's National Guard, have been mobilised.
The governor adds that more than 250 Starlink devices have been deployed across the state in case of service disruption, with more than 500 more ready to be used.
Starlink is a satellite internet service run by Elon Musk's SpaceX.
DeSantis goes on to say that some areas - such as Cedar Keys - could see "really, really significant storm surges".
"You're not going to win that battle", he says, as he urges people to avoid choosing to stay behind.
"You run away from the water and then you hide from the wind."
Storm surges could be as high as 15 feet (4.5m) in some coastal areas.
Florida Governor Ron DeSantis continues by saying the executive order has been expanded to a total of 49 counties.
He says a "huge number of counties will feel the impacts of this and we to make sure they are able to do what they need to do".
He explains that those who are in the path of the storm should expect to lose power.
He explains to Floridians that even if you are not directly in the path of the storm, you're likely to feel the knock on effects.
Image source, NoneFlorida's governor is up at the podium now with an update on the projected trajectory and impacts of Idalia.
"This storm is going to impact inland counties, particularly in northern Florida," says Ron DeSantis.
He says the exact path of the hurricane could still shift, with the most recent models suggesting it is shifting westward.
Southern parts of the state are already starting to feel impacts from the storm, he adds.
We are about to hear a storm update from Florida Governor Ron DeSantis.
You can watch a livestream by clicking the Play button at the top of this page.
Image source, NoneFema administrator Deanne Criswell
The Federal Emergency Management Agency (Fema) has said it stands ready to support Americans in the path of Hurricane Idalia, but residents must "be vigilant and heed the warnings of local officials".
"I know that the people of Florida are no stranger to storms and I encourage all Floridians to take this storm seriously," Fema administrator Deanne Criswell said at the White House's daily press briefing on Tuesday.
She said Idalia's expected storm surge poses the highest risk for loss of life, particularly in the shallow, low-lying parts of Florida's western or gulf coast.
Criswell said she had briefed President Joe Biden on the hurricane's projected trajectory and impacts, as well as the governors of Florida, Georgia and South Carolina.
The agency has already pre-deployed hundreds of its personnel, including urban search and rescue teams, and resources to the region.
Criswell also noted it has a warehouse fully stocked with food, blankets, medical supplies and other commodities that can be sent to Florida once the storm passes, in addition to 50,000 hot meals on standby from the Red Cross.
On Monday, the White House approved an emergency declaration for Florida, making federal disaster assistance available to the state.