Copper's powerful rally may have a lot more juice in it.

Even though copper prices have soared nearly 30 percent this year, metals expert Michael Dudas doesn't see signs of cracks in the rally.

"I think the fundamentals on copper medium to longer term look very supportive," Vertical Research Partners' Dudas said Tuesday on CNBC's "Futures Now."

He urged investors in August to consider buying the precious metal. Since that Aug. 22 call, copper prices have gained more than 7 percent.

"The fundamental outlook for copper from a supply and demand basis looks positive," Dudas said Tuesday, as the metal traded around three-year highs.

He points to three bullish drivers: global demand growth exceeding expectations, some shortfalls due to labor unrest and mining declines.

"We've had a multiyear decline in spending on exploration and development of the new copper mines, and that just doesn't turn around overnight," he said. "We could see a multiyear period where there could be a tightness in the copper market. which should lead to better prices."

Dudas, who has spent more than 25 years on Wall Street, has been recognized for his accuracy. StarMine ranked him number two for stock picking in the 2015-2016 calendar year for his analysis in the engineering and construction space.

His latest prediction takes into account that there could be a minor pullback in the coming months. But Dudas said any near-term softness in copper prices is a buying opportunity.