GREEN COVE SPRINGS – Forget about other storm warnings that never materialized. Hurricane Matthew poses an imminent danger to Clay County and the surrounding areas, according to Clay County Emergency Management officials.

“Heed cautions,” said John Ward, deputy director of Clay County’s Office of Emergency Management. “If you’re in an evacuation zone, leave. Bring your pets with you. Get your family preparedness plans together. Now is the time to take action. Come Friday, it’s too late; it’s hunkering down and waiting it out.”

According to the latest models Thursday, the county’s Emergency Operations Center estimates an onset of tropical-storm force winds (40-plus miles per hour) mid-morning Friday and going through late morning Saturday, with the brunt of the storm hitting Clay County around 7 p.m. Friday and through the night.

“Potentially, this will be a storm event like no one in Clay County has ever seen,” Ward said. “We can pray it’s going to go east, but if it stays on its current track, we could be looking at tropical-storm force winds for 24-28 hours.”

A severe, 10-minute thunderstorm with 40-mph gusts can cause major damage power outages.

“So multiply that by 24-28 hours,” Ward said. “We’re talking about widespread damages and heavy outages that could last for days.”

Friday night’s winds could reach hurricane-force levels (73-plus mph). The St. Johns River may see six-foot swells, based on the latest models Thursday, with 9- or 10-foot swells hitting ocean communities.

Evacuations have begun in Clay County along the river and Doctors Lake, as well as tributaries. Black Creek, for now, is not an evacuation zone, based on the latest models.

The following shelters are available, with more to be added if necessary:

— Keystone Heights High School (general population)

— Orange Park High School (for people with pets)

— Lake Asbury Junior High School (for people with special medical needs)

The shelters will provide some food and, possibly, a small number of cots.

“They aren’t the Hilton, but they’re safe and available for folks who need a place to go,” Ward said.

Ward spoke in a conference room inside the EOC building in Green Cove Springs, which opened in April 2011 and is fortified to withstand 150-mph winds. The EOC media center has extensive communication resources, including redundant systems, from the most advanced technology all the way down to ham-radio operations, so if one system goes down another is available.

EOC is the command-and-control center of Clay County during a storm. It coordinates with the National Hurricane Center as well as state, regional and local agencies. The top government officials of Clay County were in meetings and conference-calls here, attempting to anticipate and account for every possibility of Hurricane Matthew’s effects.

Meanwhile, roadways around the county were crowded as residents sought to stock up on supplies, such as water, bread, canned goods, batteries and other staples. Many grocery stores had tiers of empty shelves, their items already scooped up by waves of customers.

Pumps at several gas stations were draped with yellow plastic — sold out. Other stations had long lines for fuel.

Mary Jane Tobler of the Pier Station neighborhood was at a Kangaroo gas station on State Road 16.

“I tried the Sunoco up the street, and they didn’t have any gas left,” she said. “They were completely out.”

Ward compared this storm to Hurricane Floyd in 1999 in its size and strength, but Floyd was further off the coast. Hurricane Matthew is expected to hug the East Coast, within “tens of miles,” he said.

The last direct hit in the Clay County area was Hurricane Dora in 1964.