CHARLESTON, S.C. -- A hurricane warning has been issued for parts of the Texas and Mexico coasts as Tropical Storm Dolly churns through the Gulf of Mexico.

Forecasters at the National Hurricane Center in Miami said that the warning in Texas extends from Brownsville to Port O'Connor. The government of Mexico also issued a hurricane warning from Rio San Fernando northward to the U.S. border.

Forecasters said it's likely Dolly will become a hurricane winds and rain will reach the warning area within 24 hours, but they don't expect it to become a major storm. They said the storm would turn northward and slow down as time progressed.

At 11 p.m. Eastern, Dolly was located about 435 miles southeast of Corpus Christi, Texas. It was moving at about 17 mph and had maximum sustained winds near 50 with higher gusts.

Residents along the Texas-Mexico border kept a watchful eye on Tropical Storm Dolly on Monday, stocking up on plywood, generators and flashlights as forecasters predicted the storm would strengthen into a hurricane later this week and make landfall.

The storm was expected to bring high winds and dump 10 to 20 inches of rain in coastal areas near the U.S.-Mexican border. Emergency officials feared major flooding problems and urged coastal residents to prepare.

Shell Oil said it was evacuating workers from oil rigs in the western Gulf Of Mexico, and the federal government was trying to decide whether they could begin construction on a new border fence, which was to be combined with levee improvements along the Rio Grande in Hidalgo County.

Dolly was expected to make landfall Wednesday as a Category 1 storm with sustained winds of 74 mph to 95 mph.

A tropical storm warning was also issued north of Port O'Connor to San Luis Pass.

Cristobal Moves Offshore

Meanwhile, Tropical Storm Cristobal is headed for the open Atlantic as forecasters discontinued tropical storm warnings along the Carolinas.

Cristobal, which is still packing winds of 65 mph with higher gusts, brought heavy rain and rough surf to the coast of drought-stricken North Carolina.

The storm's heaviest winds and rains, though still offshore, have led to strong rip currents along the beaches.

At 5 a.m. EDT, the center of Tropical Storm Cristobal was located about 265 miles east-northeast of Cape Hatteras, N.C., and about 660 miles southwest of Halifax, Nova Scotia. The storm is forecast to start losing its tropical characteristics late Tuesday.

Hurricane Fausto Weakens

In the Pacific, Hurricane Fausto increased to a category 2 storm, but it is now weakening over the open northeast Pacific Ocean.

As of 8 a.m. EDT, the center of Fausto was located about 475 miles west-southwest of Cabo San Lucas, Mexico. Its maximum sustained winds are at about 80 mph, and continued weakening is predicted during the next two days.