Hurricane Rita is forecast to move over another warm eddy during the next 12 hours and could regain some intensity as it continues its track toward Texas, the National Hurricane Center said Thursday night.

Rita weakened Thursday from a top-of-the-scale Category 5 hurricane to a Category 4 as it swirled across the Gulf of Mexico.

The storm may gain strength but it is unlikely to reach its early winds speeds, according to Local 6 meteorologist Tom Sorrells.

"I really believe that it reached its zenith when it had winds of 165 or 170 mph," Sorrells said. "It just about did itself in. "I don't think it is going to rage like it did in the last 24 hours."

The National Hurricane Center's projected path shows the storm missing downtown Houston and hitting a less populated section of Texas, closer to Louisiana.

"The problem with this is that after if makes landfall, come 2 p.m. Monday, it is still right there in Texas," Sorrells said. "We are talking about wind like Katrina and winds like Tropical Storm Allison that flooded Houston in 2001."

Rita was the third strongest hurricane ever in the Atlantic before it weakened but it could still be the strongest hurricane on record to ever hit Texas, according to forecasters.

"This is really a historic storm," Local 6 meteorologist Larry Mowry said. "The strength that it has gained in the last 24 hours is remarkable. It's probably never been seen before in the history of hurricanes, at least since we have been recording them."

At 5 a.m.., the center of Rita was located near latitude 26.8 north, longitude 91.0 west or about 290 miles southeast of Galveston and about 250 miles east-southeast of Cameron, La.

Rita is moving toward the west-northwest near 9 mph. A gradual turn to the northwest is expected during the next 24 to 36 hours.

Data from a NOAA reconnaissance aircraft indicate that maximum sustained winds have decreased to near 140 mph with higher gusts. Rita is now a strong Category 4 hurricane on the Saffir-Simpson scale.

Houston Residents Get Inland

Hundreds of thousands of people across the Houston metropolitan area struggled to make their way inland in a vast, bumper-to-bumper exodus Thursday as Hurricane Rita closed in on the nation's fourth-largest city with winds howling at 150 mph.

Drivers ran out of gas in 14-hour traffic jams or looked in vain for a place to stay as hotels hundreds of miles in from the coast filled up. Others got tired of waiting in traffic and turned around and went home.

An estimated 1.8 million residents or more in Texas and Louisiana were under orders to evacuate to avoid a deadly repeat of Katrina.

"Whatever happens is going to happen and we are going to have a monumental task ahead of us once the storm passes," Galveston City Manager Steve LeBlanc said. "Galveston is going to suffer, and we are going to need to get it back in order as soon as possible."

Highways leading inland out of Houston, a metropolitan area of 4 million people, were clogged up to 100 miles north of the city. Service stations reported running out of gasoline, and police officers carried gas to motorists who ran out. Texas authorities also asked the Pentagon for help in getting gasoline to drivers stuck in traffic, and sent gasoline tankers to take up positions along evacuation routes to help.

To speed the evacuation, Gov. Rick Perry halted all southbound traffic into Houston along Interstate 45 and took the unprecedented step of opening all eight lanes to northbound traffic out of the city for 125 miles. I-45 is the primary evacuation route north from Houston and nearby Galveston.

An estimated 1.3 million people in Galveston, the Corpus Christi area, Beaumont, low-lying parts of Houston, and mostly emptied-out New Orleans were under mandatory evacuation orders. And about 500,000 in southwestern Louisiana were told to get out as well.

Environmentalists warned that the stretch of coast threatened by Rita is home to 87 chemical plants, refineries and petroleum storage installations, raising the possibility that the storm could cause a major oil spill or toxic release. Southeastern Texas is also home to more than a dozen active Superfund sites.

NASA evacuated Johnson Space Center and transferred control of the international space station to the Russians. Storm surge projections put most of the NASA space center, situated about 20 miles southeast of downtown Houston, underwater in the event of a hurricane above Category 2.

Rita is the 17th named storm of the Atlantic hurricane season, making this the fourth-busiest season since record-keeping started in 1851.

The record is 21 tropical storms in 1933. Six hurricanes have hit Florida in the last 13 months.

The hurricane season started June 1 and ends Nov. 30.

Watch Tom Sorrells, Larry Mowry and Michele Cimino for more on this story.