Tropical Storm Florence, now spinning some 1,500 miles from North Carolina's Outer Banks, "is forecast to be a dangerous major hurricane near the southeast U.S. coast by late next week," the National Hurricane Center said Saturday.
It should become a hurricane later Saturday as its winds increase above 74 mph.
Meanwhile, the remnants of what was Tropical Storm Gordon will soak portions of the Midwest and East on Saturday and into Sunday, likely leading to widespread and dangerous flooding.
"Many areas in Missouri, Illinois and Indiana will continue to see a risk of flooding during the day Saturday," said AccuWeather meteorologist Ryan Adamson. Some spots could see a half-foot of rain over the weekend, according to the National Weather Service.
Over 50 million people live where a flood watch or warning is in effect, mainly in the Midwest and in Texas.
As for Florence, the hurricane center said Saturday morning that "gradual restrengthening is forecast over the weekend."
The governors of both Carolinas have declared a state of emergency for each of their states.
North Carolina Gov. Roy Cooper declared a state of emergency Friday evening. Cooper said it’s “too early” to know where the storm will go, but residents should use the weekend to prepare for the possibility of a natural disaster.
In South Carolina on Saturday, Gov. Henry McMaster also declared a state of emergency due to the possible impacts from Florence. No evacuations have been ordered yet, however.
As of midday Saturday, Florence had winds of 65 mph and was crawling to the west at 7 mph. The center of the storm was about 835 miles southeast of Bermuda.
Widespread Showers, Heavy Rain and Flash Flooding this weekend. River Flooding Sunday and next week. Turn Around Don't Drown! #nwsind#INwxpic.twitter.com/pwBv8dRI1L
— NWS Indianapolis (@NWSIndianapolis) September 8, 2018
The latest forecast shows Florence nearing the U.S. East Coast as a Category 4 hurricane with 140 mph winds on Thursday. A Category 4 hurricane can cause power outages that last for weeks to possibly months, the hurricane center said. If the hurricane makes landfall with those winds – which is possible but not certain – "most of the area will be uninhabitable for weeks or months."
Heavy rain could also cause catastrophic flooding well inland from where the storm makes landfall, which is possible anywhere from Florida to New England, AccuWeather said.
The Weather Channel said that "all interests along the U.S. East Coast from Florida to New England should monitor closely the forecast of Florence. If you live in a hurricane-prone location, make sure you have a preparedness plan in place now, before any watches or warnings are issued."
The hurricane center warned that "swells generated by Florence are affecting Bermuda and will reach portions of the U.S. East Coast over the weekend. These swells are likely to cause life-threatening surf and rip current conditions."
Two other systems, Tropical Storm Helene and Tropical Depression Nine, are also spinning in central and eastern Pacific Ocean. While Helene may not affect land, the tropical depression is forecast to strengthen to Hurricane Isaac and potentially hit the Caribbean later next week.