Tropical Storm Don is expected to make landfall in southeastern Texas late today and has already shown signs of weakening, according to forecasters.
The storm will probably lose strength quickly as it moves over land in the Corpus Christi area and dissipate completely in about 48 hours, said the U.S. National Hurricane Center.
“The pressure has been slowly rising and that’s a sign that it’s weakening,” said Mike Pigott, a senior meteorologist with AccuWeather Inc. in State College, Pennsylvania. “We’re thinking it should make landfall between 8 to 10 p.m.” local time.
Don forced the shutdown of more than 11.9 percent of oil production and 6.2 percent of gas output from the Gulf of Mexico, the Bureau of Ocean Energy Management, Regulation and Enforcement said today.
The storm, with maximum winds of 50 miles (80 kilometers) per hour, is about 95 miles southeast of Corpus Christi, and bands of rain swirling out from its core have reached the coastline, according to a center advisory issued shortly before 4 p.m. local time.
Storms are watched closely because they are a threat to oil and natural gas interests in the Gulf, home to 31 percent of U.S. oil output and 7 percent of natural gas production. Coastal refineries account for 7.61 million barrels a day, or 42 percent of U.S. capacity.
Don is expected to go ashore between Corpus Christi and Brownsville, then track across the southern tip of Texas before entering the Mexican state of Coahuila sometime tomorrow, according to center maps. Tropical storm warnings and watches are posted from Galveston Island to the Mexican border.
Personnel were evacuated from 56 oil and gas platforms and four rigs in the Gulf, the Bureau of Ocean Energy Management said.
Apache Corp. reported it curtailed 49 million cubic feet of gas, up from 15.5 million yesterday, and 2,000 barrels of oil per day, up from 1,890 barrels. Apache also evacuated 368 production employees and contractors from facilities in the western Gulf, according to its website.
Northern Natural Gas told customers in a notice it was shutting production from its Matagorda Offshore Pipeline System in the Gulf that extends from Mustang Island to Tivoli.
Enbridge Inc. said in a notice that it evacuated personnel from its West Cameron 509 platform and will allow gas to free-flow to shore.
BP Plc halted production at its Atlantis platform, and Anadarko Petroleum Corp. said it evacuated workers and shut in production at six facilities.
Royal Dutch Shell Plc closed its Perdido Spar platform and Chevron Corp. said it closed an unspecified amount of Gulf production.
Don is expected to drop 2 inches to 4 inches of rain across drought-stricken southern Texas and as much as 6 inches in isolated areas, according to the center, less than forecasters originally thought.
A weather system becomes a tropical storm when it develops cyclone characteristics, and becomes a named storm when winds reach at least 39 mph. A storm becomes a hurricane when winds hit 74 mph.
The U.S. hasn’t had a direct hit from a tropical storm since Bonnie went ashore in Florida in July 2010. The last hurricane to make landfall in the U.S. was Ike, a Category 2 storm, in Texas in 2008.
Forecasters are also tracking an area of disturbed weather about 1,150 miles east-southeast of the Lesser Antilles that has a 30 percent chance of becoming a tropical cyclone in the next two days, according to the hurricane center.
That system has to contend with some wind shear and dry air and dust, all of which can prevent it from developing into a hurricane, said Bob Haas, weather group operations manager and meteorologist at MDA Information Systems Inc. in Gaithersburg, Maryland. Some forecasting models show the system becoming better organized in the next five days, however.
“The tropical wave in the eastern Atlantic bears watching,” Haas said in an e-mail today.