Crude oil prices face several factors that could send it below current levels, notably the quickly strengthening U.S. dollar, Raoul Pal of Global Macro Investor said Tuesday.

"The probability of a dollar breakout is very big. So, if that happens, then the chances of the dollar moving much more rapidly than we've seen for many, many years, and that would lead oil to go much further," he said. "So, prices in oil could go down to $30, $40 easily if the dollar moves in the way that I'm thinking it possibly will."

dipped below $81 per barrel for the first time in four years. Meanwhile West Texas Intermediate crude clocked in at $77.48 per barrel.

Read More OPEC feeling pain as oil slides to new 4-year low