Dolly became a hurricane on Tuesday and bore down on southern Texas, but forecasters don't expect it to pack too much of a punch when it comes ashore near the Mexican border on Wednesday.
Dolly intensified from a tropical storm and became the second hurricane of 2008 Atlantic storm season after gathering strength over the warm waters of the Gulf of Mexico and reaching nearly 80 miles per hour (130 km per hour).
The U.S. National Hurricane Center issued a hurricane watch for the southern Texas coast as far north as Corpus Christi.
At 11 p.m. EDT (4 a.m. British time), Dolly was 110 miles (175 km) east-southeast of the border town of Brownsville, Texas, where it was due to come ashore on Wednesday afternoon as a low-grade hurricane. Tropical-force winds will begin to lash the region's coast this evening.
The storm's predicted landfall and strength are unlikely to jeopardize sensitive offshore drilling rigs and production platforms in the U.S. and Mexican waters of the Gulf of Mexico. U.S. crude oil prices hit 6-month lows before recovering.
The National Hurricane Center has said Dolly is unlikely to become a major hurricane prior to landfall, but could dump as much as 15 inches (38 cm) of rain on South Texas and northeastern Mexico in coming days.
Though Dolly will be the weakest category of hurricane, officials in low-lying South Texas counties are worried that torrential rains could overcome levees holding back the Rio Grande River and cause flooding.
The United States has largely escaped the past two Atlantic hurricane seasons, with just one hurricane - Humberto in November 2007 - making landfall on its coasts.
But it was pummelled in 2004 and 2005, when a series of powerful hurricanes, including the catastrophic Katrina, ravaged Florida and the U.S. Gulf Coast.
AHEAD OF SCHEDULE
The 2008 Atlantic hurricane season is already a month ahead of schedule, but is unlikely to see a repeat of the devastating 2005 season. On average, the fourth tropical storm of the six-month season does not occur until August 29. Dolly, this year's fourth, formed on July 20.
