Hurricane Matthew track uncertain, but coastal areas guaranteed to get torrential rain

Not much changed overnight with Hurricane Matthew’s track, but new forecasts show more rainfall than previously expected could hammer Grand Strand coastal regions and trees could easily topple from wind gusts.

Increased storm rainfall total amounts with a potential for more than 10 inches along coastal areas was announced as a possibility early Thursday morning, which could lead to road washouts and sinkholes, along with flooding at vulnerable structures in low-lying areas.

"If this trend continues then the impact level may need to be increased to extreme, especially given antecedent rainfall and soil saturation conditions across the area," said Steve Pfaff, meteorologist with the National Weather Service in Wilmington, N.C. in a 6:30 a.m. threat assessment.

A morning update Thursday mostly mirrored previous updates from Wednesday evening with "no significant changes" made to the latest forecast storm track, but showed more rainfall could pound the coastline, Pfaff said.

"Rainfall will begin during Friday, while direct rainfall associated with Matthew would occur Friday night through Saturday night. Rain may be heavy at times with the risk for flash flooding increasing," said Pfaff, who said the greatest risk of flash flooding would be Saturday night.

A large swath of tropical moisture not associated with Matthew is moving into the area, creating rainy conditions, then influence from Matthew is expected to fuel rainfall.

Moderate storm surge impacts could also occur with 2 to 4 feet inundation north of Cape Fear, N.C. to 4 to 6 feet south of Cape Fear, N.C. with the highest values from Myrtle Beach southward, with the surge’s brunt crashing in Saturday, Pfaff said.

Gusty winds near 60 mph could blow along the coasts with gusts in the 40-50 mph range felt farther inland. Pfaff warned some trees embedded in already saturated soil could easily topple. Downed trees and wind could create power outages and structural damage.

“Large waves for days on end” could result at area beaches as dangerous maritime conditions are likely to last into next week as the storm meanders off the coast, Pfaff said on an 8:30 a.m. conference call Thursday.

As far as Matthew’s path, the storm is still expected to ride along the S.C. coast then make a dramatic curve out to sea with impacts from the hurricane being felt along the Grand Strand late Friday into Saturday night, as the storm likely morphs into a Category 2 storm when it nears Grand Strand-area waters, forecasters said.

Pfaff said huge question marks exists for the storm’s path after it makes its dramatic loop south from the South Carolina coast.

The storm still churned within the cone of uncertainty as potential evacuations loomed over Horry and Georgetown counties.

"Do not let your guard down as any adjustment to the west would support greater impacts," said Pfaff in the threat assessment.

The powerful storm weakened some as it interacted with the Bahamas Wednesday, but began regaining some strength as it headed toward Florida early Thursday morning at about 12 mph as a Category 3 storm, soon likely to beef back up to a Category 4, weather authorities said.

Hurricane watches were issued for the coast of Georgia and a hurricane warning was in effect for almost the entire east coast of Florida as an 8 p.m. update was issued Wednesday.

No watches or warnings have been issued yet for Horry or Georgetown counties, but a hurricane watch reached into South Carolina for the South Santee River area early Thursday morning. Pfaff said hurricane or tropical storm watches could be issued for the area later Thursday afternoon.

Gov. Nikki Haley ordered evacuations for Zone A for Horry and Georgetown counties at noon Thursday. Zone A is the area east of Kings Highway and closest to the coast. An estimated 200,000 could be leaving the coast line Thursday, and officials said they were prepared to enact lane reversals on U.S. 501, but none had been ordered Thursday morning.

Elizabeth Townsend: 843-626-0217, @TSN_etownsend

This story was originally published October 6, 2016 at 12:29 PM with the headline "Hurricane Matthew track uncertain, but coastal areas guaranteed to get torrential rain."