Florence was officially downgraded to a still-deadly Category 2 hurricane, but the storm is still expected to bring flash floods, storm surge, high winds and heavy rain as it makes its way toward the East Coast of the United States Thursday.

According to ABCNews.com, the National Hurricane Center said Florence was moving northwest at about 12 miles per hour and located 170 miles southeast of North Carolina and about 220 miles southeast of Myrtle Beach.

Forecasters are warning of dangerous storm surge, which could reach 13 feet on parts of the Carolina coast. The effects of the storm will begin being felt Thursday night as rain and high winds begin to impact North and South Carolina.

Areas to the north and south of the Carolinas will also feel the impact of the massive storm.

The hurricane is expected to stall along the coast through Friday, which could result in as much as 30 inches of rain being dumped on both Carolinas before moving over the Appalachian Mountains. Flash flooding and possible tornadoes are expected in Virginia and eastern North Carolina.

In total, over 5.25 million people live in areas under hurricane warnings or watches and another 4.9 million people are under tropical storm warnings or watches.

As for Hurricane Florence’s impact on travel, airlines have already announced thousands of cancellations through the weekend. Many carriers have issued travel advisories and are waiving change fees, including Alaska Airlines, American Airlines, Delta Air Lines, Frontier Airlines, JetBlue, Southwest Airlines, Spirit Airlines and United Airlines.

Impacted passengers are being advised to reach out to their carriers and travel agents to determine the proper course of action over the coming days. According to FlightAware.com, airlines have already canceled over 1,000 flights through Friday and more are expected through the weekend.

Cruise passengers are also being impacted by Florence, with Carnival Cruise Line being forced to revise itineraries for Carnival Pride and Carnival Horizon. In addition, Norwegian Cruise Line changed its plans for Norwegian Dawn and Norwegian Escape and Royal Caribbean Cruise Line modified the sailing of Grandeur of the Seas.