HOUSTON, June 14 (Reuters) - U.S. oil companies were closelywatching a large tropical disturbance in the southern Gulf ofMexico, but were not changing operations despite the system's 70percent chance of developing into a tropical cyclone over thenext 48 hours, according the U.S. National Hurricane Center.
Leading oil producer in the U.S.-regulated Gulf of MexicoShell Oil Co, the U.S. arm of Royal Dutch Shell, saidit was monitoring the storm on Sunday.
"We're keeping an eye on it, but no changes in operationsyet," said Shell spokesman Ray Fisher on Sunday.
The system does not yet have a closed circulation needed toclassify it as a tropical storm or hurricane, but was producingwinds near gale force or about 38 miles per hour (61 kilometersper hour), or about half the strength of winds generated in theweakest hurricane.
The National Hurricane Center as well as academic andprivate weather forecasters are expecting a below-averageAtlantic Ocean hurricane season for the United States this year.The season began on June 1 and lasts through Nov. 30.
Some forecasters have warned that the best chance for atropical storm to develop in the oil production areas off theU.S. Coast could come early in the hurricane season. A strongEl Nino is expected to form in the eastern Pacific later thissummer and is expected to send high winds across the southernUnited States, disrupting tropical storm development.
The Gulf of Mexico produces 17 percent of U.S. crude oilproduction and 5 percent of dry national gas output, accordingto the U.S. Energy Information Administration.
Gulf Coast states of Texas, Louisiana and Mississippi arealso home to more than 45 percent of the nation's crude oilrefining capacity, according to the EIA. (Reporting by Erwin Seba; Editing by Bernard Orr)