From an article in today's San Diego Union-Tribune:

But in a sign of just how volatile the market has become, independent retailers reported yesterday that wholesalers were warning them to brace for an additional 10-cent increase by today.

“The rumor today is that Valero and Shell are having refinery problems and will have to shut down, so they're out on the independent market buying up all the gasoline they can,” said Dave Whitlow, owner of Spirit Auto Center in Lakeside, an unbranded retailer.

Don't be surprised when you drive past the gas stations.