By Patrick Phillips, Digital Content Manager

WEST COLUMBIA, SC (WCSC/WIS) -

South Carolina's governor says he will review the next update to Hurricane Irma's forecast track late Friday afternoon before making a decision on ordering mandatory evacuations for Saturday morning.

That order could still come by 10 a.m. Saturday, the time he mentioned at a news conference on Thursday.

"Until we say otherwise, coastal residents should plan on evacuating Saturday at 10 a.m," he said. "That may change at 6 o'clock this evening."

McMaster said he wants to see the next update from the National Hurricane Center, which will come at 5 p.m. and will include an update to the center's official hurricane track. He has scheduled a second news conference of the day for 6 p.m.

"I need to say and need to make it clear, if we had to evacuate the whole coast starting at 10 o'clock tomorrow as we are prepared to do, we are prepared to do it," McMaster said.

He said he did not think it would be necessary to issue an order to close schools statewide.

"The decision on school closings will continue to be made by school districts themselves," he said.

Most Lowcountry school districts made the decision early Thursday afternoon to close their schools and offices through Tuesday.

McMaster also rescinded an order of mandatory evacuations for healthcare facilities, including hospitals, nursing homes, assisted living facilities and alcohol and substance abuse treatment facilities, in Charleston, Berkeley, Dorchester, Georgetown and Horry Counties.

The order remains in effect in Beaufort, Colleton and Jasper Counties, he said.

The most recent forecast tracks from the National Hurricane Center have shifted the track of the storm to the west, predicting it will go across the Florida Peninsula and then into Georgia. But that forecast track also has the typical so-called cone of uncertainty, a wide area where the storm could actually go.

By the fifth day out, the longest point in such a forecast track, that cone can be more than 200 miles wide, which means South Carolina could still feel the effects of the storm.

Copyright 2017 WCSC. The Associated Press contributed to this report. All rights reserved.