U.S. crude oil prices tumbled 2 percent on Thursday, while gasoline futures surged nearly 3 percent. That is a clear sign that traders are engaging in so-called crack spread buying, said John Kilduff, founding partner at energy hedge fund Again Capital.
Anticipating refinery outages on the U.S. Gulf Coast, traders were buying refined products such as gasoline and selling crude oil, the primary feedstock at refineries, he told CNBC.
Right now Harvey is a Category 1 hurricane, with 85 mph winds. But it could strengthen to a Category 3 hurricane with winds of at least 111 mph, which could send the price of gasoline up 27 cents in parts of the country, Kloza said.
"It's a temporary event, but you could have a temporary price shock for portions of the United States that are fed by the Gulf Coast," he said.
Andy Lipow, president of Lipow Oil Associates, is currently anticipating a roughly 10 cent impact on gasoline prices east of the Rockies.
If Harvey makes landfall as a Category 3 hurricane, it will take refineries caught in its path two to three weeks to return to normal operations, according to Lipow.
"That is because in Category 3 there is more likely to be lots of evacuations, widespread power outages, wind damage, flooding and difficulty getting workers back to the facilities," he told CNBC in an email.