Now, while the US East Coast gets prepared for the Category 3 storm (earlier downgraded from four), Hurricane Florence satellite images revealed that two more storms are swirling above the Atlantic Ocean, forming a rare phenomenon.
"These violent storms form over the ocean, often beginning as a tropical wave - a low pressure area that moves through the moisture-rich tropics, possibly enhancing shower and thunderstorm activity", the agency explains.
Accuweather meteorologists said the storm's most likely path would take it toward the southern or central Texas coast, though they and others cautioned the forecast could change quickly.
Maximum sustained winds have decreased to near 75 miles per hour (120 kph) with higher gusts.
NHC forecasters say that a slow southwestward motion is expected for the next couple of days.
Joyce could become a tropical storm within the next day or so.
Storm surges are one of a hurricane's most risky effects. Within 12 hours it was back to a tropical storm.
But the Met Office says Helene could be heading east towards the south-western corners of the United Kingdom, with the tip of Ireland among the worst affected. Rescue crews used boats to carry more than 360 people from rising water in the river town of New Bern, North Carolina, while many of their neighbours awaited help. Mandatory evacuations have been issued for much of the SC and North Carolina coastline. Although Olivia is expected to move over the islands as a tropical storm, it could still bring worse impacts than recent Hurricane Lane to some areas, the center said.
The NHC is estimating that as many as 20 inches of rain could fall in some places along the southern North Carolina coast while bringing in excess of 10 inches of rain in parts of SC.
The storm, presently called Invest 95L, is predicted to bring one to three inches of rain to the Houston area, according to meteorology blog Space City Weather.