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
The storm surge in Florida is expected to rise "dramatically" over the next few hours, boosted by high tide, according to Kevin Guthrie, the director of Florida's Division of Emergency Management.
Guthrie said that two or three feet (1m) is expected in the Tampa Bay area, with as much as 4ft (1.2m) expected in Cedar Key on Florida's northwest coast.
DeSantis asks people not to run generators inside homes or garages, and says these must be run outside and 20 feet (6 metres) away from doors and windows.
"We don't want to see fatalities as a result of misuse of generators," he says.
"Don't put your life at risk by doing anything dumb. You don't want to be messing around with these winds, there will be things flying all over the place," he says.
The lights in the briefing room appear to briefly cut out but then come back on as he speaks.
Governor DeSantis says that 30,000 personnel are staged and ready to help restore power in the wake of the storm.
Additionally, DeSantis said that "a lot" of debris is likely to be created by the storm and urged local residents to take care, particularly with downed power lines that may still be "hot".
DeSantis added that 11,000 generators are ready to be deployed, and that 4.5m litres of fuel are already staged, with more expected to arrive by truck.
Image source, ReutersDeSantis says 16ft (4.9m) surges are expected, and he emphasises "that's life threatening".
"Do not go outside in the midst of this. Once the storm passes, do not drive in flooded streets. Do not touch downed power lines - assume they're live," DeSantis says.
Florida Governor Ron DeSantis is addressing the media on the latest Hurricane Idalia updates.
He says the hurricane will make landfall in the next two hours. Stay with us for more updates.
Dozens of counties in western and central Florida have some form of evacuation order in place as Hurricane Idalia nears with potentially life-threatening conditions to come.
You can check the websites of each county to see the latest advice. Here's a few of the latest evacuation orders:
Idalia could continue to strengthen before it makes landfall in the Big Bend region of Florida's coast in a few hours, the National Hurricane Centre (NHC) says.
"Catastrophic storm surge and destructive winds are nearing the... Big Bend region," it says in its latest advisory.
The remote region is just south-east of the state capital, Tallahassee, and is sparsely populated.
The National Weather Service in Tallahassee called Idalia “an unprecedented event” because no major hurricanes on record have ever passed through the area.
"While Idalia should weaken after landfall, it is likely to still be a hurricane while moving across southern Georgia, and near the coast of Georgia or southern South Carolina late today," the NHC says.
The hurricane should emerge off the south-eastern US coast early on Thursday and move eastward later in the week, it says.
The map below reflects the very latest data from NHC which they released less than an hour ago.
We've just heard Idalia has rapidly intensified into a Category 4 hurricane. It is now 60 miles (97km) west of Cedar Key, Florida, and 90 miles south of Tallahassee, Florida.
A hurricane of this severity is likely to have maximum sustained winds of 130mph (215 km/h).
According to the National Hurricane Centre's scale, Category 4 means "catastrophic damage will occur".
"Most trees will be snapped or uprooted and power poles downed," it says. "Power outages will last weeks to possibly months".
"Most of the area will be uninhabitable for weeks or months," it adds.
Hurricane Idalia has intensified into a major Category 4 hurricane, according to the National Hurricane Center, external's latest update.
Under their categorisation system, this means "catastrophic damage will occur".
Chris Fawkes
BBC Weather presenter
Image source, Getty ImagesHavana in Cuba was drenched by Idalia as it passed on its way to Florida
The 2023 Atlantic hurricane season is forecast to be more active than average, and we’re still two weeks away from the peak of the season.
The main driving factor is that oceans are a lot warmer than average and it’s these warm waters that fuel the development of hurricanes.
Idalia poses by far the greatest threat of all the storms so far this season. One of the major concerns is that water temperatures in the Gulf of Mexico are above normal, but especially so near to the US coasts where the waters are 2-3C warmer than average.
This will lead to rapid intensification of Idalia on its final approach to Florida with the current forecast predicting sustained winds of 125mph (201km/h), with gusts up to 155mph.
The ominous trend is that with each successive forecast, the expectation is for ever stronger winds.
Landfall is expected within hours in northwest Florida with torrential rain and a potentially life-threatening storm surge, which is going to lead to some severe flooding.
Even as the winds begin to subside, the threat of extreme rainfall and heavy flooding will extend to both North and South Carolina too. Idalia looks like it will be a very dangerous storm.
Image source, ReutersSteve Pizzano helped board up a friend's souvenir shop in Clearwater Beach ahead of the hurricane arriving
Image source, EPALocals boarded up buildings with plywood and filled sandbags to divert water away from homes and businesses
Image source, EPAPeople have been warned to evacuate as the storm hurtles towards Florida's coast
Image source, EPAPetrol pumps were wrapped in cellophane to prevent them from being damaged in the rain
Footage of a storm surge in Gulfport, Florida, is circulating on social media, showing the water level reaching the mid-points of car tyres.
US weather broadcaster WeatherNation posted this clip, external of the scene, with one man seen trudging through knee-high flood water.
To read more about how deadly a storm surge can be, click here.
Watch: How quickly water rises in a storm surge
The National Hurricane Center has just released its latest forecast of the path that Hurricane Idalia may take.
It is still expected to make landfall at around 08:00 local time (12:00 GMT) in Florida's northern panhandle before sweeping east across the state.
Dozens of airports in Florida have closed as the hurricane moves closer.
Tampa International Airport closed on Tuesday, and will stay shut until it can assess any damage later in the week. It's closed to all visitors and the site "is not equipped to function as a shelter," the airport said on Monday.
Florida's second biggest airport - Orlando International Airport - said it does not foresee any "significant impact" to their operation.
But it added that flight delays and cancellations are likely to occur because of heavy rainfall and strong winds, and urged passengers to check directly with the airlines for any updates.
Gainesville Regional Airport and Naples Airport have also warned of possible flight cancellations.
Idalia has just been upgraded to a Category 3, and is forecast to become a Category 4 when it makes landfall in Florida's Big Bend region. But how are hurricanes categorised?
In the United States, hurricanes are classified on a scale of 1 to 5, with Category 5 being the most intense.
That's based on the Saffir-Simpson Hurricane Wind Scale, which measures the storm's sustained wind speed, as well as how deadly it can be.
Storms reaching Category 3 and above are considered "major hurricanes, external" because of their potential for loss of life and damage to property.
The scale was developed in 1971 by civil engineer Herbert Saffir and meteorologist Robert Simpson, after whom the system is named. Simpson was also director of the US National Hurricane Center at the time.
Idalia has been upgraded to a Category 3 hurricane as it moves towards northwest Florida, the US National Hurricane Center has just said.
"Idalia is a Category 3 hurricane on the Saffir-Simpson Hurricane Scale. Additional strengthening is forecast, and Idalia is forecast to become a Category 4 hurricane before it reaches the Big Bend coast of Florida this morning," the weather agency said.
Nicholas Yong
Reporting from Singapore
Good morning. It's 01:45 in Florida, 06:45 in London and 13:45 in Singapore.
The National Hurricane Centre is projecting that Hurricane Idalia will reach an "extremely dangerous Category 4 intensity" when it makes landfall in the Florida Big Bend region.
"Catastrophic storm surge inundation" is expected, while "destructive life-threatening winds" may also result.
Florida Governor Ron DeSantis has warned that time is running out for residents to evacuate. Evacuation orders are already in force across 20 counties.
If you are among those affected, please stay safe. My colleagues in London will now bring you the latest updates on Idalia.
According to the National Hurricane Center, Hurricane Idalia is predicted to move along this path.
Image source, .
Mike Wendling
in Tampa
Tampa City Hall was doused with rain overnight
Over the last 24 hours, the projected track of the storm has steadily moved north and west, towards Florida's panhandle.
It is now projected to hit land much closer to Tallahassee, the state capital - a city of about 385,000 people that includes a large student population.
Tallahassee is inland, so residents don’t have to worry about storm surges. But the city also has a lot of trees, and during a hurricane, that means a greater risk of downed power lines and power outages.
The storm is strengthening, say forecasters with the US National Weather Service. Wherever it eventually ends up, the eye of Idalia is expected to make landfall on Wednesday morning local time.
Meanwhile here on Florida’s west coast, we’re reaching the expected peak of wind strength. We’re far from the centre of the storm, but strong gusts will continue through the night.
Nadine Yousif
BBC reporter
Image source, National Hurricane CenterA graphic shared by the National Hurricane Centre shows just how high water levels could rise with a storm surge
Hurricane Idalia is predicted to cause a storm surge in the state of Florida.
That's a term used to describe a change in sea level caused by a storm. The strong winds can generate large waves, pushing high levels of water inland.
The waves can be powerful enough to erode beaches and highways, and even take down buildings.
In general, storm surges account for about half of deaths associated with tropical storms in the US, according to the National Weather Service
To make matters worse, hurricane Idalia coincides with a super moon - a full moon that is in close proximity to earth - which is known to have an impact on tide levels, due to the gravitational pull that occurs when the sun, moon and earth are in alignment.
Read more on how deadly a storm surge can be here.