Hurricane Matthew is the most powerful storm to threaten the Atlantic coast in more than a decade. Here's what we know now about the powerful storm.

What happened overnight

Hurricane Matthew was downgraded to a Category 3 storm. It has not made landfall and the eye of the storm remains offshore. However, it remains an extremely dangerous storm. Strong winds and intense rain were hammering the coast as the storm's outer bands worked their way north.

Where's the storm now?

The western edge of the eyewall is near Cape Canaveral, bringing 90 mph winds still with the potential to gust up to 130. As of 6:15 a.m., it was about 170 miles south-southeast of Jacksonville, according to the National Weather Service. It is expected to continue moving northwest Friday and, by Friday night, turn north. It's moving parallel to the coast.

The National Weather Service is mincing now words, forecasting life-threatening storm surge along the coast and 8 to 12 inches of rain. Complete and total destruction of structures on barrier islands near Jacksonville is likely. The St. John's River in northeast Florida/southeast Georgia could be overwhelmed by all the rain. Even those somewhat inland could feel the effects of flooding.

The power outages have begun

More than 300,000 in Florida are without power Friday morning. The number will be climbing rapidly as the storm moves closer to and up the coast. Up to 2.5 million Florida Power & Light customers are expected to lose power.

Thousands of flights canceled

Matthew is wreaking havoc on the travel industry. As of 11:30 p.m. ET on Thursday, airlines had canceled more than 4,800 flights nationwide for a period stretching from Wednesday through Saturday, according to flight-tracking service FlightAware. That total could grow even further depending on the storm's path.

Haiti: Matthew left a broad swath of destruction

The Haitian Interior Ministry said at least 283 people were killed when the storm struck Tuesday with 145-mph winds, torrential rain and driving storm surge. Hurricane Matthew is the most powerful single hurricane on record to make landfall in Haiti, Cuba and the Bahamas. At least four died in the Dominican Republic, Haiti's neighbor on the island of Hispaniola.