Hurricane Irma, the most potent Atlantic Ocean hurricane ever recorded, is expected to make landfall in South Florida over the weekend. Mar-a-Lago, President Trump's waterfront golf club, evacuated ahead of the storm. (Reuters)

President Trump's Mar-a-Lago Club — which Trump has christened the “Winter White House” — was ordered to evacuate on Friday, along with the rest of ritzy Palm Beach island, as Hurricane Irma's powerful winds and storm surge approached the Florida coast.

The evacuation order went in place at 10 a.m. Friday, part of a series of orders that will require 155,000 people to leave their homes in Palm Beach County alone.

The Palm Beach County evacuations cover low-lying areas along Lake Okeechobee, as well as a long swath of neighborhoods along the Intracoastal Waterway and the barrier islands off Florida's east coast. On those barrier islands, some of the country's most expensive real estate sits on a narrow spit of land, with sometimes just a few hundred feet of terra firma separating the Atlantic Ocean and the Intracoastal Waterway.

The town of Palm Beach, home to Mar-a-Lago, sits on one of those narrow islands. On Friday, the town ordered all residents to be out by 5 p.m. The county said the first tropical-storm-force winds were expected to arrive on the island on Saturday afternoon.

“Mandatory evacuation for the entire town remains in effect. Please gather the essentials for three to four days, including clothing, medicine, important documents and communication devices,” the town's order said. “Please relocate west of US-1 until this storm passes if you do not plan to depart the county/state.”

U.S. Route 1 is a north-south highway on the mainland about a mile from Mar-a-Lago.

Mar-a-Lago is a members-only social club, with ballrooms, a few guest suites, and living quarters for Trump himself. The property stretches east-to-west across the island, touching both the ocean and the intracoastal waterway — its name means “Sea-to-Lake.” The estate has existed since the 1920s, when it was built by heiress Marjorie Merriweather Post. It has been through multiple hurricanes before, but Irma is an especially strong and dangerous storm, which could push an enormous amount of seawater onto the land.

Mar-a-Lago was already closed even before Irma approached. It operates only during the winter social “season” in Palm Beach, which runs roughly from Halloween to Mother's Day. Its staff during the off-season is relatively small: The club hires dozens of temporary foreign workers during the high season to work as cooks, waiters and housekeepers.

A large swath of the Florida coast, including Palm Beach island, is under a storm surge warning — meaning “there is a danger of life-threatening inundation from rising water moving inland,” according to the National Hurricane Center.

Trump also owns three golf courses in South Florida: one in West Palm Beach, one in Jupiter, and one in Doral, west of Miami. None of the others was in a mandatory evacuation zone, at least as of Friday morning.

Of those three clubs, the one in Jupiter might be the most vulnerable to a storm surge. It sits about two miles inland from the coast but only a few thousand feet from a large creek.

In a statement Friday, a spokeswoman for the Trump Organization said that all three of those Trump golf clubs were already closed. The Doral club also includes a resort open to the public: The Trump Organization was urging anyone with reservations there to “make alternative lodging arrangements,” and waiving cancellation and change fees.