An oil tanker heads out to open water as a surfer takes advantage of waves ahead of Hurricane Beryl’s arrival in Port Aransas, Texas on Saturday. Eric Gay/Associated Press

CORPUS CHRISTI, Texas — Powerful winds and rain approached Texas Sunday morning as Beryl was expected to turn back from a tropical storm into a hurricane overnight and pound a long stretch of coast with heavy downpours, howling gusts and dangerous storm surge.

A long stretch of Texas’ shoreline was under a hurricane warning as Beryl’s outer bands were forecast to begin lashing the coast Sunday. Landfall was expected early Monday, and officials in several coastal counties issued voluntary evacuation orders to urge tourists along the beach for the Fourth of July holiday to leave.

The earliest storm to develop into a Category 5 hurricane in the Atlantic, Beryl, caused at least 11 deaths as it passed through the Caribbean earlier in the week. The storm’s devastating winds and storm surge, fueled by the Atlantic’s record warmth, tipped doors, windows, and roofs off homes.

“We’re seeing the outer bands of Beryl approach the Texas coast now, and the weather should be going downhill especially this afternoon and evening,” Eric Blake, a senior hurricane specialist with the National Hurricane Center, said Sunday morning. “People should definitely be in their safe space by nightfall and we’re expecting the hurricane to make landfall somewhere in the middle Texas coast overnight.”

Texas officials warned people along the entire coastline to prepare for possible flooding, heavy rain and wind. The hurricane warning extended from Baffin Bay, south of Corpus Christi, to Sargent, south of Houston.

In Corpus Christi, officials asked visitors to cut their trips short and return home early if possible. Residents were advised to secure homes by boarding windows if necessary and using sandbags to guard against flooding.

Employee Elizabeth Landry said Saturday that traffic has been nonstop for the past three days at Ace Hardware in the city as customers buy tarps, rope, duct tape, sandbags, and generators.

“They’re just worried about the wind, the rain,” she said. “They’re wanting to prepare just in case.”

Ben Koutsoumbaris, general manager of Island Market on Corpus Christi’s Padre Island, said there has been “definitely a lot of buzz about the incoming storm,” with customers stocking up on food and drinks, particularly meat and beer.

The White House said Sunday that the Federal Emergency Management Agency had sent emergency responders, search-and-rescue teams, bottled water, and other resources along the coast.

Visitors crowd the beaches on Saturday, in Port Aransas, Texas, ahead of Hurricane Beryl’s arrival. Eric Gay/Associated Press

Some coastal cities called for voluntary evacuations in low-lying areas prone to flooding, banned beach camping, and urged tourists traveling on the Fourth of July holiday weekend to move recreational vehicles from coastal parks. In Refugio County, north of Corpus Christi, officials issued a mandatory evacuation order for its 6,700 residents.

Lt. Gov. Dan Patrick, who is acting governor while Gov. Greg Abbott is traveling in Taiwan and issued a preemptive disaster declaration for 121 counties.

“Beryl is a determined storm, and incoming winds and potential flooding will pose a serious threat to Texans who are in Beryl’s path at landfall and as it makes its way across the state for the following 24 hours,” Patrick said Saturday in a statement.

Beryl battered Mexico earlier this week as a Category 2 hurricane, toppling trees but causing no injuries or deaths before weakening to a tropical storm as it moved across the Yucatan Peninsula.

Before hitting Mexico, Beryl wrought destruction in Jamaica, St. Vincent and the Grenadines, and Barbados. Three people were reported dead in Grenada, three in St. Vincent and the Grenadines, three in Venezuela and two in Jamaica.

Associated Press writer Mark Thiessen in Anchorage, Alaska, and radio reporter Julie Walker in New York contributed.