Grain futures on the CME Group floor are expected to continue the rally that closed out Thursday's session when the opening bell rings in Chicago Friday morning. Early calls for the commodities are corn 3-5 cents higher, soybeans up 4-6 cents and wheat 8-10 cents higher, according to private sources.

As of 6:15 AM CDT, in overnight electronic trading, the September and December CME Group corn futures contracts were both 3 cents per bushel higher at $3.79 1/4 and $3.93 3/4 per bushel, respectively. August soybeans were 5 3/4 cents higher at $10.26 3/4 per bushel, while September wheat was 9 1/2 cents higher at $6.27 1/2 per bushel. See more from the overnight trade.

The wheat trade -- fueled by drought worries in Russia -- will likely be the driver through Friday's trade, one trader says. And, look for more volatility to build. "Things truly could be just revving up here in the wheat options," the trader told Marketeye late Thursday.  "Look for two-sided trade to possibly creep into the picture now that we got the volatility uptick that so many were waiting for."