By Gary McWilliams
HOUSTON, Oct 6 (Reuters) - Oil and gas producers were gearing up for the second storm in as many months to affect the U.S. Gulf Coast as a fast-moving tropical storm off Central America threatens to develop into a hurricane.
Tropical Storm Nate was moving toward Mexico's Yucatan Peninsula at about 21 miles per hour (34 kph) at around midday on Friday and is expected to strike the U.S. Gulf Coast by early Sunday, according to the National Hurricane Center.
About 15 percent of U.S. Gulf of Mexico crude production and 6 percent of natural gas production were shut in on Thursday.
ConocoPhillips on Friday said it began evacuating non-essential personnel from its Magnolia oil platform in the central Gulf of Mexico, joining other six other producers that have withdrawn workers or curbed production.
Matt Rogers, meteorologist at Commodity Weather Group, said the speed of the storm could leave it as a Category 1 hurricane with up to 80 mile per hour (129 kph) winds, or even a tropical storm at landfall.
"In our view it is not going to be strong enough to do damage" to offshore production facilities, he said. "Usually when storms move this quickly they have troubles developing," he said.
The region's oil refineries are still recovering from Hurricane Harvey, which shut production at some plants for weeks. Producers also curtailed some production but quickly resumed output.
On Thursday, refiner Phillips 66 said it was preparing to shut its 247,000 barrel per day Alliance, Louisiana, refinery as a precautionary measure. It is located 25 miles (40 km) south of New Orleans.
Commodity Weather forecasts Nate to bring moderate rainfall when it makes landfall somewhere west of Mobile Bay, Alabama, and east of New Orleans, Louisiana. It expects between 4 inches and 6 inches (10-15 centimeters) of rain to fall in the path of the storm.
The U.S. Gulf of Mexico is home to about 17 percent of the nation's crude oil output and 5 percent of dry natural gas output, according to the U.S. Energy Information Administration. More than 45 percent of the nation’s oil refining capacity is along the U.S. Gulf Coast. (Reporting by Gary McWilliams; Editing by Alistair Bell)