COLORADO: Tropical Storm Isaias formed in the Gulf of Mexico on Wednesday and is forecast to strengthen into a hurricane before slamming into the southern US coast early on Saturday, bringing heavy rain, storm surges and possible tornadoes across several states, the National Hurricane Centre said.

The storm is expected to pass through areas with significant offshore oil and gas production, along with onshore refining facilities, which could pressure inventories and already-high prices at the pump.

Michael Brennan, director of the NHC, said in a video briefing on Wednesday that Isaias could be a "major" hurricane — Category 3 or higher — when it makes landfall and could have "multiple, life-threatening impacts from storm surge, heavy rainfall flooding and hurricane force winds."