Karen, barely holding on to tropical storm strength, stalled in the Gulf of Mexico on a curving path that’s expected to take the system across Louisiana before final landfall in southwestern Alabama.
The storm, with sustained winds of 40 miles (65 kilometers) per hour, was some 130 miles south-southwest of the port of Morgan City, Louisiana as of 2 p.m. New York time, the National Hurricane Center said in an advisory. It would be downgraded to a tropical depression if sustained winds drop below 39 mph.
“This system is very, very weak,” said Matt Rogers, president of Commodity Weather Group LLC in Bethesda, Maryland. “It’s just barely a tropical storm at 40 mph and is really on the cusp of depression status.”
Chevron Corp. began resuming offshore operations and a coastal Louisiana parish lifted a mandatory evacuation order. Even so, gusty winds, heavy rains and flooding threaten the southeastern U.S. for the next several days. Once Karen goes ashore, remains are expected to move across central North Carolina toward Washington, according to AccuWeather Inc. in State College, Pennsylvania.
About 48 percent of the Gulf’s natural-gas production and 62 percent of the oil output was closed because of the storm, the U.S. Bureau of Safety and Environmental Enforcement said today. In all, 271 platforms and 20 rigs were evacuated, accounting for 866,807 barrels a day of oil and about 1.8 billion cubic feet of gas.
Karen is the 11th named storm of the Atlantic hurricane season, which began June 1 and ends Nov. 30, and would be the second to hit the U.S. this year. Tropical Storm Andrea made landfall in northwestern Florida in June and then moved up the East Coast.
Karen was disrupted after encountering dry air, while high shear -- when winds blow at varying speeds or directions at different altitudes -- blew the biggest thunderstorms away from the center, breaking up its structure, forecasters said.
Strong winds out of the west “have driven dry air from the western Gulf of Mexico into Karen’s core, making it difficult for heavy thunderstorms to build on the west and south sides of Karen’s center of circulation,” Jeff Masters, co-founder of Weather Underground, wrote in his blog.
The system’s strength will probably be little changed before landfall and the storm is expected to become a depression tomorrow, the center said.
A tropical storm warning was in place from Morgan City to the mouth of the Pearl River on the Louisiana-Mississippi line, while a storm watch was in effect for New Orleans, Lake Maurepas and Lake Pontchartrain and from east of the Pearl to Indian Pass in the Florida panhandle.
Forecasters yesterday ended a hurricane watch for parts of the Gulf Coast. Officials in Plaquemines Parish, Louisiana, which hugs the Mississippi River south of New Orleans to the Gulf, changed its mandatory evacuation order to a voluntary one, according to the parish’s website.
The official track has Karen crossing Louisiana southeast of Houma late tonight and early tomorrow, then going ashore south of Fairhope, Alabama, as a depression. The system may drive tides as much as 3 feet (1 meters) higher than normal from Terrebonne Bay in the Mississippi delta to Cedar Key, Florida, and drop as much as 6 inches (15 centimeters) of rain.
“The main impact is probably going to be heavy rainfall,” Dan Pydynowski, a senior meteorologist at AccuWeather, said by phone. “There will probably be enough wind, at least on the coast, that there could still be power outages and some minor damage. If you have to deal with a tropical system, this is a best case scenario because it’s not all that strong.”