Houston — Texas officials urged coastal residents to brace for a looming hit by Beryl, which was a tropical storm on Saturday but was expected to regain hurricane strength as it moves across the warm waters of the Gulf of Mexico.

A hurricane warning was declared for a stretch of the state's coast from Baffin Bay, south of Corpus Christi, to Sargent, south of Houston, and forecasters said the storm's center was likely to approach the state Sunday and then make landfall the following day. Storm surge warnings were also in effect.

“We’re expecting the storm to make landfall somewhere on the Texas coast sometime Monday, if the current forecast is correct,” said Jack Beven, a senior hurricane specialist at the National Hurricane Center in Miami. “Should that happen, it’ll most likely be a Category 1 hurricane.”

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 islands earlier in the week. It then battered Mexico 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.

Texas officials warned people along the entire coastline to prepare for possible flooding, heavy rain and wind as the storm nears.

Lt. Gov. Dan Patrick, who is acting governor while Gov. Greg Abbott is traveling in Taiwan, 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.

Some coastal cities called for voluntary evacuations in low-lying areas prone to flooding, banned beach camping and urged tourists traveling on the July 4 holiday weekend to move recreational vehicles from coastal parks.

Mitch Thames, a spokesman for Matagorda County, said Saturday that officials issued a voluntary evacuation request for the coastal areas of the county about 100 miles southwest of Houston to inform the large number of visitors in the area for the holiday weekend.

“I certainly don’t want to ruin the holiday weekend for our visitors. But at the same time, our No. 1 goal is the health and safety of all our visitors and of course our residents. I’m not so much worried about our residents. Those folks that live down there, they’re used to this, they get it,” Thames said.

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

“We’re taking the storm very serious and we’re asking the community to take the storm very serious as well,” Corpus Christi Fire Chief Brandon Wade said during a Friday evening news conference.

Traffic has been nonstop for the past three days at an Ace Hardware in Corpus Christi as customers buy up tarps, rope, duct tape, sandbags and generators, employee Elizabeth Landry said Saturday.

“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's “definitely a lot of buzz about the incoming storm,” with customers stocking up on food and drinks — particularly meat and beer.

“I heard there’s been some talk about people having like hurricane parties,” he said by telephone Saturday.

In Refugio County, north of Corpus Christi along Texas' Gulf Coast, officials issued a mandatory evacuation order for its 6,700 residents Saturday.

Refugio County Judge Jhiela “Gigi” Poynter, the county’s top elected official, said that based on the growing confidence of Beryl’s track and the uncertainty regarding the storm’s intensity and holiday weekend traffic that is already backing up roads, she made the decision to call for the mandatory evacuation.

“I would rather be cautious and let Tropical Storm Beryl come crawling in with a little bit of rain and a little bit of wind to an empty Refugio County than the alternative if it were to strengthen more than the predictions, which we know has happened with several storms in the past,” Poynter said in a video posted on Facebook.

As of Saturday night, Beryl was about 330 miles southeast of Corpus Christi and had top sustained winds of 60 mph, according to the National Hurricane Center. It was moving northwest at 13 mph.

Before hitting Mexico and moving into the Gulf, Beryl had already spread destruction in Jamaica, St. Vincent and the Grenadines, and Barbados this week. Three people have been reported dead in Grenada, three in St. Vincent and the Grenadines, three in Venezuela and two in Jamaica, officials said.

Mexican authorities had moved some tourists and residents out of low-lying areas around the Yucatan Peninsula before landfall, but tens of thousands remained to tough out the strong winds and storm surge. Much of the area around Tulum is just a few yards (meters) above sea level.

The city was plunged into darkness when the storm knocked out power as it came ashore. Screeching winds set off car alarms across the town. Wind and rain continued to whip the seaside city and surrounding areas Friday morning. Army brigades roved the streets of the tourist city, clearing fallen trees and power lines. No deaths or injuries have been reported.

Vertuno reported from Austin, Texas. Associated Press writers Mark Thiessen in Anchorage, Alaska, and Martín Silva in Tulum, Mexico, contributed to this report.