One of Wall Street's biggest bears is warning the economy is on a collision course with a recession.

Gluskin Sheff's David Rosenberg has little doubt growth will turn negative in 2019 as the stock market flounders.

"We're going into a recession," the firm's chief economist and strategist said Wednesday on CNBC's "Trading Nation." "I think it will be this coming year."

Rosenberg predicted in November on the program that the historic bull run was cracking. However, he was uncertain whether it would cause an outright recession.

With the Dow and plunging 14 and 16 percent, respectively, from their all-time highs, that view has changed.

"We've got more than 80 percent chance of recession just based on the fact the Fed is tightening policy," he said. "This tightening of financial conditions that we've seen in the markets is going to end up having a cascading effect on the economy for the first few quarters of this year."

Rosenberg, who has been known as a perma-bear on Wall Street for decades, is not predicting a prolonged downturn. But its effects, he contends, will be downright painful — noting risk premiums are going up across asset classes.

"The severity of the recession doesn't give you a get out of jail free card when it comes to how the markets are going to respond," he said.

According to Rosenberg, getting out of the recession will be a serious dilemma for Washington.

"How are we going to stimulate fiscal policy? We already did that at the peak of the cycle," Rosenberg said. "We don't have the fiscal ammunition."