President Donald Trump has declared a state of emergency in Louisiana as a growing tropical storm nears landfall.
Storm Barry has been gathering speed over the Gulf of Mexico in recent days.
Officials say sustained wind speeds have grown to 50mph (80km/h) and may still reach hurricane strength by the time it makes landfall.
It is expected to bring a storm surge and heavy rainfall to the city of New Orleans – which has already seen thunderstorms and flash floods.
The National Weather Service warns that flooding from the slow-moving storm poses the greatest risk.
Between 10-20in (25-50cm) rain is forecast to hit the state, where the Mississippi River is already nearing flood levels.
The president’s declaration frees up wide-ranging federal resources which can be used to help in the emergency situation.
What is the latest with the storm?
The National Weather Service (NWS) say the storm is continuing to crawl at speeds of 5mph towards Louisiana.
- How do hurricanes form?
- Hurricanes, typhoons and cyclones explained
Forecasters believe it will make landfall late on Friday or early Saturday, before weakening over the Lower Mississippi Valley later this weekend.
While there is no definitive link between climate change and Storm Barry, rising temperatures are increasingly a factor in making the impact of events like this more intense.
As the air has warmed over recent decades it is now able to hold much more moisture, meaning tropical storms are pre-loaded with large amounts of rain.
The warming world is also making these storms more sluggish. Over the past seven decades tropical events like Barry have slowed down, going 20-30% less quickly over land in North America.
This is what happened with Hurricane Harvey in 2017, when it weakened to a tropical storm and then stalled for days over the Houston area dumping enormous quantities of rainwater which cost lives and did huge damage.
Sea levels have also increased as a result of global heating, so if winds are blowing towards shore, this makes flooding much more likely during high tides.
If sustained winds from the storm exceed 74mph, Storm Barry will be declared a hurricane and become the first of the 2019 Atlantic season.
How is Louisiana preparing?
Officials have ordered thousands of residents in some low-lying areas to evacuate.
Mayor of New Orleans, LaToya Cantrell, has not issued a city-wide evacuation order because it is not a category three hurricane or above.
Residents have been warned to prepare for the storm, by stocking up on drinking water and non-perishable food, as well as other emergency supplies.
President Trump’s declaration, made in advance of landfall, will make Federal Emergency Management Agency (FEMA) resources available.
He posted on Twitter that national and local officials were working closely together and urged people to prepare.
The NWS said on Friday that the Mississippi River levels are already at a depth of 16.9ft (5.15m) with crest levels of up to 19ft expected.
The US Army Corps of Engineers has maintained it is “extremely confident” in the 20-25ft levee system shielding New Orleans.
Governor John Bel Edwards described the incoming storm as “very severe” – citing National Hurricane Centre (NHC) warnings flooding could be “life-threatening”.
“This is going to be a major rain event across a huge portion of Louisiana,” he said on Thursday.
“Look, there are three ways that Louisiana floods: storm surge, high rivers and rain. We’re going to have all three.”
Mayor Cantrell has said the New Orleans’s anti-flood water pumps are working at “optimal capacity” as the storm nears, but warned it will not be enough.
She, and other city officials, asked people to bring in their rubbish bins and clear gardens and streets in order to prevent debris from choking street drains and gutters or becoming airborne “projectiles”.