Hurricane Bret, its winds diminishing, pounded the most desolate stretch of Texas's southern Gulf Coast tonight, sparing the region's big population centers the brunt of its force but still threatening floods along 125 miles of shoreline from here to the Mexican border.

As the slow-moving storm crossed narrow Padre Island at 5 p.m. CDT, its winds diminished from 140 mph earlier in the day to 125 mph, and meteorologists downgraded it from a Category 4 hurricane to Category 3. By midnight, its winds were down to 105 mph, making it a Category 2. Bret's eye reached land at 6:45 p.m. CDT midway between Corpus Christi and the Rio Grande Valley.

Forecasters warned of potentially extensive flooding from a possible sea surge of 10 to 15 feet, combined with 10 to 15 inches of rain in some areas.

Thousands of people in the Coastal Bend region, a 50-mile stretch of shoreline near Corpus Christi, were told to evacuate. City officials went door to door to urge 15,000 to 20,000 residents to leave low-lying areas, and the message was the same for people in border communities 125 miles south in the Rio Grande Valley.

Emergency planners took solace in the fact that the area of mostly flat land between Corpus Christi and the border where Bret made landfall is sparsely populated. It came ashore in Kenedy County, a roughly 1,200-square-mile area with a population of about 420. Kenedy and neighboring Kleberg County, with a population of 31,500, are home to huge cattle ranches, including the 800,000-acre King Ranch, the biggest in Texas. The cattle in the counties vastly outnumber the humans. By contrast, to the north, Nueces County, which includes Corpus Christi, has a population of 315,000. And on the Gulf Coast south of where Bret came ashore, Willacy and Cameron counties, in the Rio Grande Valley, have a combined population of about 340,000.

"The good news is that the core of the hurricane . . . is not over the more populated areas," said Max Mayfield of the National Hurricane Center in Coral Gables, Fla.

King Ranch president Jack Hunt said about 50 people had been evacuated from the ranch, but there was no way to protect about 55,000 head of cattle.

"The cattle will just have to ride it out," Hunt told the Associated Press. "It's not practical to move them out."

About 45 minutes after satellite images showed the western edge of Bret's 35-mile-wide eye over Padre Island, the National Weather Service office in Brownsville said: "Father Kelly at the House of Prayer compound seven miles east of Sarita in Kenedy County reported heavy rain in horizontal sheets. Winds were estimated in excess of 70 mph." The compound -- about two miles from Baffin Bay and 30 miles south of Corpus Christi -- was directly in the storm's path as it came ashore.

"I hope my fellow Texans say a prayer for those fellow Texans that are in harm's way," Gov. George W. Bush said today. He declared seven counties -- Aransas, Cameron, Kenedy, Kleberg, Nueces, San Patricio and Willacy -- disaster areas, and President Clinton approved unspecified disaster assistance last night, Reuters reported.

"We're very thankful," meteorologist Mark Lenz told AP, that Bret's eye crossed the coastline county that was the least populated.

After forming four days ago, Bret headed northward Saturday night from the southern Gulf of Mexico, turned slowly to the west today and by early afternoon was moving toward the west-northwest at 8 mph, according to the National Hurricane Center. An hour after the storm's eye edged onto Padre Island, a 75-mile-long barrier island between Corpus Christi and Brownsville, the hurricane center said Bret's maximum sustained winds had diminished to 125 mph, and it forecast gradual weakening over the next 24 hours.

At midnight CDT, Bret's winds had declined to 105 mph and its forward speed slowed to 7 mph. Brownsville meteorologists said an estimated 15 inches of rain had fallen in northeastern Kenedy County, while Corpus Christi got about 4 inches.

Waves reached 26 feet high late this morning at a buoy off the coast of Baffin Bay, about 40 miles south of Corpus Christi, the Weather Service said. Tonight, the swell was 16 feet, and tides were running three feet above normal. A Corpus Christi forecast said the swells would "continue to make their way toward the Texas coast through tonight and Monday," but with diminishing wind, the storm surge forecast dropped to six to eight feet above normal.

Like Hurricane Andrew, which devastated South Florida in 1992, Bret was compact and exceptionally powerful as it plowed toward land. But an important difference between the two is that Andrew, which killed 41 people and caused $30 billion in damage, was a fast-moving storm. Plodding Bret could linger after making landfall, causing massive flooding, said Jim Hoke, a Weather Service official in Washington.

The Weather Service issued a tornado watch for areas near Corpus Christi and in the Rio Grande Valley, saying Bret was likely to bring twisters.

Bret "has the clear potential of producing a major disaster," said Hoke, who appeared at a briefing with federal emergency management officials. "It has the ingredients to threaten life and property in many ways. These ways include storm surge, flooding from rains, high winds and tornadoes."

It is the first hurricane to make landfall this year and the first to batter the Texas coast since 1989, although Tropical Storm Charley flooded the coast with 18 inches of rain last August, killing 19 people.

Far to the east in the Atlantic, Cindy, the season's third hurricane, was downgraded to a tropical storm this afternoon as it churned 1,200 miles east of the Lesser Antilles. The first hurricane since the season began June 1, Hurricane Arlene, petered out in the Atlantic.

In Corpus Christi, a city of about 315,000, emergency officials braced for flooding along the waterfront, a potential disaster for the local tourism industry.

"For our waterfront, it will be devastating," said Juan Ortiz, the city's assistant emergency management coordinator. "It would only take a storm surge of four to five feet" to cause flooding in the area, with its numerous hotels and condominium complexes.

Because a hurricane spins counterclockwise, Corpus Christi braced for a lashing by Bret's strongest winds. Businesses and homes were shuttered from here to Brownsville in the Rio Grande Valley, and highways leading inland were jammed with traffic in some places.

The American Red Cross set up 14 shelters that were housing more than 3,400 people tonight from nine coastal counties. The agency had readied 13 emergency response vehicles that can serve up to 1,000 meals a day.

Schools in San Antonio, 125 miles northwest of Corpus Christi, were opened to shelter at least 1,000 people, and Kelly Air Force Base opened its empty barracks to 5,000 others. Even pets were being welcomed to air-conditioned tents.

"With the compactness of this storm and the intensity of this storm, when it hits, it's really going to hit," Corpus Christi Mayor Loyd Neal said as Bret plowed ashore. "The thing we keep asking our citizens to do is to believe us, this is a very serious storm."

CAPTION: STORM SURGE (This graphic was not available)