ASHEVILLE - Hurricane Irma, now a Category 4 storm, continued to churn its way through the Caribbean Sea on Friday on its way to the U.S. coast.

Irma's path is not yet clear, though the hurricane could severely impact North Carolina.

Gov. Roy Cooper declared a state of emergency, which went into effect at 8 a.m. Thursday, to prepare for the storm.

On Friday morning, the National Weather Service updated its predictions for Hurricane Irma's path, shifting the storm's track west, which would spare Western North Carolina from the worst of the storm's power.

As of early Friday, the U.S. National Hurricane Center said Irma’s maximum sustained winds have decreased to near 155 mph, making it a Category 4 storm, down from 5.

Irma was about 500 miles southeast of Miami and moving north at 16 mph, leaving a trail of destruction in its wake. The hurricane center said some fluctuations in strength are likely over the next day or two but Irma is expected to stay a Category 4 storm.

Excessive rainfall and damaging wind gusts are possible Monday and Tuesday in Western North Carolina, according to the National Weather Service at Greenville-Spartanburg International Airport.

Friday should bring more information for the mountains. "The closer we get, the more confidence we'll have as to the eventual track," said Greenville NWS meterologist Justin Lane. "Once it gets within the three-day window is when we start to get more confident."

"The storm is still quite a ways away," said Tony Sturey, warning coordination meteorologist with the National Weather Service in Greenville. "As the system reaches Florida, it's going to turn. How sharp that turn is can make a big difference."

MORE: WNC could get 4-6 inches of rain

MORE: Irma leaves destruction behind in Caribbean; at least 10 dead

Steve Wilkinson, a Greenville-based NWS meteorologist, said mountain residents can expect "beautiful" weather through Sunday, the proverbial calm before the storm.

"Getting into Monday and Tuesday is when the storm will be moving north into North Carolina, though the track is highly uncertain," he cautioned.

Wilkinson said tropical storm-strength gusts of 40-50 mph are not out of the question for the mountains, with higher gusts at mountain peaks.

Wilkinson urged the public to continue to watch NWS data. "I’m a believer that when there is no threat, we should tell people that," he said. "But we’re not there yet."

The last hurricanes to significantly affect Western North Carolina were the 2004 Hurricanes Ivan and Frances, which soaked the region and caused extensive damage and flooding.

By the time those storms hit the area, they had been downgraded to tropical depressions.

The last actual hurricane to hit the mountains was Hurricane Hugo in 1989, which made landfall near Charleston as a Category 4 storm.

The National Hurricane Center had issued three hurricane advisories as of Thursday morning: the Category 1 Katia in the Gulf of Mexico, with Irma and the strengthening Category 1 Jose farther east. Jose is forecast to continue west-northwest over the next few days.

USA Today contributed to this report.