A record-setting 'once-in-200-years rainfall event' left 22 million Americans on the East Coast on flood watch as rains have closed down roads, waterlogged crops and showed little sign of stopping.

Meteorologist Ryan Maue of Weather Bell Analytics told NBC New York: 'It's going to be a slow-motion disaster'.

North and South Carolina have been hit the worst, with up to 12 inches of rain falling in Wilmington, North Carolina, on Friday night alone, and two deaths have been reported so far in the states.

President Barack Obama issued a state of emergency in South Carolina on Saturday and state emergency officials said flash flood warnings were issued for numerous counties and that some homes had already been evacuated, including in the coastal county that includes Myrtle Beach.

More than 15 inches of rain have fallen over the popular beach area since Friday, with more expected, the National Weather Service in Wilmington, North Carolina, reported.

South Carolina could get more rain in three days than it normally gets during the entire fall.

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A few hours before high tide, wind-driven waves crash into a fishing pier in Virginia Beach, Virginia, on Friday

Tony and Sandy Mathena, from Raleigh, North Carolina, make a quick retreat up the steps to The Isles Restaurant & Beach Club as high tide come in at the west end of Ocean Isle Beach, North Carolina

A man walks his bicycle through high water at the City Market in downtown Charleston, South Carolina on Saturday

A vehicle navigates the flood water after high tides and heavy rains left parts of downtown Charleston, South Carolina

Dillon Christ (front) and Kyle Barnell paddled their canoe down a flooded street in Charleston, South Carolina

A man walked his dog through flood waters during high tide on the Isle of Palms in South Carolina on Saturday

Saeideeh Sharifian, 72, of Fayetteville, North Carolina, was killed when the storms brought down a 60-foot pine tree on to the Toyota Corolla she was a passenger in on Interstate 95, north of Godwin.

Sylvia Arteaga, 56, drowned when her car flooded in standing water on a road in Spartanburg, South Carolina. County coroner Rusty Clevenger told the Spartanburg Herald-Journal that she was likely unable to escape the car when it became submerged.

McGrady uses a paddle board to navigate a flooded Rader Street to meet her children who coming back from school on Friday

The Greenville-Spartanburg Airport in South Carolina recorded 2.3 inches of rain Saturday, smashing the previous record of 0.77 inches set in 1961, according to John Tomko, National Weather Service meteorologist at Greenville-Spartanburg.

'This one is extraordinary in that it's such a prolonged event,' he said.

Downtown Charleston was closed to incoming traffic Saturday as rain washed out some bridges, flooded roads and left some motorists stranded as flood waters engulfed their cars.

'Where we normally are dealing with flooding for a few hours, we're dealing with it in days here,' Charleston Police Chief Greg Mullen told The Associated Press.

'We're seeing areas flood today that did not traditionally flood.'

In North Carolina, Agriculture Commissioner Steve Troxler says farmers are starting to see the impact of the continuous rain on their crops.

Apples in Henderson County are starting to split open because they're waterlogged and farmers can't get into the fields to harvest other crops.

'I had one farmer tell me this is like getting all of your cash assets, put them on a clothesline, waiting for the wind to blow them away,' he said.

Flooded roads were closed throughout the mid-Atlantic region and power companies reported scattered outages in several states.

Flood watches and warnings also are in effect in Delaware and parts of New Jersey, Maryland and Virginia and it looks as though there will be no reprieve from the combination of northeastern storms and tropical moisture until Monday.

A car is stuck in floodwaters along Central Avenue in Sea Isle City, New Jersey. The state got pounded by heavy rain and strong winds that were expected to bring coastal flooding this weekend, even though the state is no longer in the anticipated path of Hurricane Joaquin

Heavy surf pounds the beach along the boardwalk at Coney Island on Saturday as heavy storms drench the East Coast

A man crosses a flooded street as water nearly reaches his knees in Ocean City, Maryland on Saturday

A seagull takes off as a man attempts to drive down a flooded street in Ocean City, Maryland, on Saturday

In New Jersey, high-tide cycles caused at least one home to collapse just north of North Wild Wood at about midnight on Saturday, according to NJ.com.

Nearby residents posted on social media that the 2.5-story house was lifted up off its foundation and floated into an inlet.

Down south in Virginia, Bubba's Seafood restaurant in Virginia Beach was so overwhelmed with water that dolphins were swimming at its doors.

NWS meteorologist Doug Anderson told Daily Mail Online that Hurricane Joaquin is 'slow moving' and he is 'expecting it to last through Monday night'.

The weather service issued a warning for residents living along the coast to be alert for rising water.

A combination of high water and high waves could result in beach erosion and damage to docks and piers.

This forecast by the National Hurricane Center predicts the path of Hurricane Joaquin (shown in white) in the coming days. It predicts that after Tuesday morning, the threat will be over and the storm will move out to sea

A man wades through flood water on Atlantic Avenue during high tide in Wachapreague, Virginia, on Friday

PETA field worker, Heather Johnson, right, pulls her colleague veterinarian, Dana Windsor, though flood water on a rescue canoe to the dry ground on Front Street during high tide in Norfolk, Virginia

Once the rain ends, dangerous flooding triggered by the heavy rainfall is expected across much of the Carolinas and parts of Georgia, Virginia and New Jersey over weekend, US forecasters said.

'These kind of prolific rainfalls are not unprecedented, but this is definitely one for the history books,' said NWS forecaster Dave Loewenthal in Wilmington.

'We have had numerous reports of road closures.

'We have had roads washed out, sinkholes forming,' he said. 'It's really a mess and we are going to have significantly more problems with multiple rivers reaching moderate flood (level) or higher.'

A statement from the North Carolina governor's office said up to 500 residents of Brunswick County had been evacuated from their homes Friday night into early Saturday morning due to flooding from heavy rains and a levee failure in South Carolina.

'It's definitely a life-threatening situation,' said NWS meteorologist Steve Pfaff.

'There were people that were stuck in vehicles that were flooded and water in some of the homes was up over the electrical outlets,' he said.

It was not clear whether the deaths of four people in a small plane crash Friday near Lake Hartwell, South Carolina, was weather related.

Official advisories in Charleston, South Carolina, told residents to stay indoors and out of knee-deep water.

'I'm a good citizen and I'm going to obey,' Shirley Jones told CNN. 'I'm going to hole up in my apartment and clean out my dresser.'

The National Weather Service told NBC that South Carolina is facing a 'once-in-200-years rainfall event'.

'A significant flooding event is developing across southern South Carolina and portions of eastern Georgia,' the NWS said.

'A powerful low-pressure system over the southeast United States will slowly move northeast across the area through Sunday. Accompanying this storm will be several weather hazards, most notably the potential for dangerous flooding from heavy rainfall and high tides.'

A woman wades waist-deep in a flooded street in Charleston, South Carolina. The National Weather Service says the risk of flooding will continue through Monday morning

Will Cunningham rode his bike down Station 29 on Sullivan's Island in South Carolina while his friend kayaked

Wendy McGrady, left, pushes her two twin boys, Tucker, left, and Jacson, right, both 7, on paddle board to home after they arrived from their school on Friday in Norfolk, Virginia

Increased threat of landslides and life-threatening rip currents pose as a threat in the Carolinas and up the coast.

'This is not just rain,' South Carolina Gov Nikki Haley told CNN. 'It's going to be the heaviest rain we've ever seen.'

'The touch news for North Carolina and especially South Carolina is continued rain,' North Carolina Gov Pat McCrory added.

'Our state is now likely to miss any direct impact from the hurricane, but there's still significant danger of flooding, high seas, heavy surf, beach erosion and overwash.'

Hurricane Joaquin has become less of a threat to the United States as forecasts show the storm curving into the Atlantic and weakening in the upcoming days.

It was centered on Saturday morning about 120 miles northeast of San Salvador, Bahamas, and about 700 miles southwest of Bermuda. It has maximum sustained winds of 125mph, and is moving northeast at 13mph.

Melissa and Heath King take their dog Molly for a walk down a flooded Lodge Road in Poqouson, Virginia

Quinn Hurt looks across Atlantic Avenue as he attempts to cross the flooded street in Wachapreague, Virginia

High-tide cycles caused at least one home to collapse just north of North Wild Wood, New Jersey, at about midnight on Saturday

Residents in the area where the home collapsed posted on social media that the 2.5-story house was lifted up off its foundation and floated into an inlet

Joaquin pulled away from the Bahamas after battering the area for more than two days but it expected to pass well off the US coastline on Sunday, the U.S. National Hurricane Center said.

The Miami-based NHC said the storm strengthened slightly Saturday morning, regaining potentially catastrophic Category 4 status, but some weakening was expected over the next 48 hours.

A hurricane warning is still in effect for parts of the Bahamas. The Bermuda Weather Service has issued a tropical storm warning and a hurricane watch for Bermuda.

Earlier this week, the governors of New Jersey, Virginia, North Carolina, South Carolina and Maryland declared states of emergency and announced measures including mobilization of National Guard troops in preparation for the storm.

Before the first easterly shift in Joaquin's trajectory, New York and New Jersey - where Superstorm Sandy killed more than 120 people and caused $70billion of property damage in October 2012 - both faced potential threats from the storm.

Meanwhile, the fate of 33 crew aboard a cargo ship missing off the Bahamas in heavy seas whipped up by Hurricane Joaquin was unknown on Friday as the storm battered the island chain for a second day.

Paul Banker (left) paddled a kayak while his wife Wink Banker (right) took photos of the flooded street

Storm waters squirts from a storm drain in a flooded street in downtown Charleston, South Carolina on Saturday

Nelson Gonzalez navigates his bike around flood water along on New York Avenue in Atlantic City, New Jersey

A customer walks to an open store in downtown Charleston, South Carolina, on Saturday, where there is a risk of flooding continuing through Monday

A car barrels through deep water as heavy rain falls in Atlantic City, New Jersey, on Friday and storms continue to his the East Coast

Heavy rains forced the closure of Harrell Road in Stafford County, Virginia. Virginia Gov Terry McAuliffe declared a state of emergency in preparation due to rains

News that the vessel, carrying 28 Americans and five Polish nationals, had lost contact with shore came as forecasters shifted the likely track of the potentially catastrophic storm further away from the US East Coast, but there were still warnings about the possibility of severe flooding in the Carolinas from unrelated heavy rains.

The 735ft ship, named El Faro, was headed to San Juan, Puerto Rico, from Jacksonville, Florida, when it reported it had lost propulsion and was listing and taking on water, the Coast Guard said.

'We are very surprised that we lost all communication with the ship,' Mike Hanson, a spokesman for El Faro's owner, Tote Maritime Puerto Rico, told Reuters on Saturday.

'The ship was simply in the wrong place at the wrong time,' he added, saying Joaquin was just a tropical storm when El Faro set out from Jacksonville but later intensified rapidly into a major hurricane.

Late Friday afternoon, the US National Hurricane Center downgraded Joaquin, the third hurricane of the 2015 Atlantic season, to a Category 3 hurricane on a scale of 1 to 5, down from its previous Category 4 ranking.

By Friday evening, Joaquin's core was beginning to move away from the central Bahamas, the Miami-based center said in an 8pm EDT advisory, adding that hurricane conditions would continue for several more hours.

The Coast Guard said there had been no further communications after the El Faro issued the emergency call at about 7.30am Thursday.

The ship was in the eye of Joaquin about 35 miles north of Crooked Island when it issued the distress call, according to Chief Ryan Doss with the Coast Guard in Miami.

'We have had 20-foot seas reported so it's going to take a while to get into the area,' Doss said.

A Coast Guard cutter headed to help after taking part in a separate rescue mission off Haiti, while two Air Force Hurricane Hunter planes searched in vain for the US-owned El Faro.

A boy pushed his brother's kayak down Station 30 while their mother pushed a bike on Sullivan's Island

The El Faro, a cargo ship carrying 33 crew, went missing off the Bahamas in heavy seas whipped up by Hurricane Joaquin was unknown on Friday as the storm battered the island chain for a second day

Hurricane Joaquin is veering away from the US East Coast, but the area is still being slammed by storms

'The low cloud cover makes satellite communications difficult,' Doss said, while the winds and high seas made it hard to get close enough by sea or air.

'The storm is so bad and slow moving it's hard for our planes to get low enough to inspect the surface of the water.'

Hanson said the ship was equipped with a marine transponder, a satellite phone and GPS locators on the containers.

'We checked them all,' he said.

The El Faro, built in 1975, recently underwent a complete updating, Hanson said.

Captain Stephen Russell, director of the Bahamas National Emergency Management Agency, said earlier there were no reports of deaths or injuries in the Bahamas from Joaquin.

He cited reports of extensive flooding and structural damage on at least two smaller islands in the archipelago, but apart from some roofs ripped off houses, damage seemed to be limited.

The storm dumped torrential rain over parts of the Bahamas but its hurricane-force winds missed the larger islands and the main cities and cruise ship ports of Freeport and Nassau.

Dark clouds loom over the Bay Creek Marina development in Cape Charles, Virginia, on Saturday

Cars drive through a flooded intersection during high tide on Chincoteague Island, Virginia, as police in the state say they've responded to dozens of vehicle crashes in the heavy rain

Vehicles manuever through flood water along First Street in Buckroe area of Hampton, Virginia, on Friday