Hurricane Matthew — one of the most powerful storms to threaten the Atlantic coast in recent history — continue to set off alarms as it closes in on the Southeast coast. Here's what we know so far: Get the latest here.

Where is Matthew now?

Matthew continues to move north towards the South Carolina coast, the National Hurricane Center said in a statement. Matthew was downgraded to a Category 2 storm, and as of 5 a.m. ET Saturday, the hurricane was located about 20 miles southeast of Hilton Head, S.C., moving at 12 mph.

Maximum sustained winds were reported at 105 mph, with devastating storm surge flooding occurring in South Carolina and Georgia, the National Hurricane Center said.

Early Saturday morning, the National Weather Service in Charleston, S.C., advised residents near Tybee and Hilton Head not to venture outside as significant coastal flooding were reported near the region.

On Friday, South Carolina Gov. Nikki Haley made a blunt statement to residents: "This is the last time you will hear my voice asking you to evacuate," she said, calling out islands and cities by name. State officials were particularly worried about high water, in the form of 8-foot storm surges, inundating barrier islands and bringing life-threatening flooding to historic Charleston.

Where is the storm headed later today?

As of early Saturday, Matthew is moving north at 12 mph towards the coast of South Carolina and is expected to move near the coast of southern North Carolina, the National Hurricane Center said in its advisory.

Forecasters expect Matthew to stick close to the coast of Georgia and South Carolina over the weekend before veering out to sea — perhaps even looping back toward Florida in the middle of next week as a tropical storm.

Storm surges remain a serious threat

Matthew is expected to produce total rain accumulations of 8 to 12 inches over the Atlantic coast from central Florida to eastern North Carolina, forecasters said. Some areas could see as much as 15 inches, which could lead to flooding and flash flooding, even in inland areas. The most important threat comes from storm surges, which have been predicted to be as high as 12 feet that can lead to destructive and life-threatening conditions.

Power outages affecting more than a million people

More than one million customers in Florida were without power Friday, though the numbers could climb as the storm moves closer to the coast and heads north this weekend.

Travel issues continue

Matthew is wreaking havoc on the travel industry. As of Friday, airports in Fort Lauderdale and Orlando were shut down, and some cruises were being rerouted.

Airports in southern Florida have resumed limited flight schedules Friday, but flights remain halted in the north where Matthew continues to spin. Since Wednesday, airlines had canceled more than 4,500 flights nationwide. As the storm moves north, so do cancellations with Atlanta, Charleston and Savannah taking the largest hits.