Chicago Board of Trade (CBOT) grains futures closed higher on Wednesday with corn prices rising nearly two percent on forecasts for potentially stressful crop weather in the Midwest corn belt.

The weather jitters come as commodity funds hold large net short positions in corn, wheat and soybeans, leaving the markets vulnerable to bouts of short-covering.

The most active corn contract for July delivery rose 7.5 cents, or 1.99 percent, to 3.8475 dollars per bushel. July wheat delivery rose 9 cents, or 2.07 percent, to 4.4475 dollars per bushel. July soybeans added 7.25 cents, or 0.79 percent, to 9.305 dollars per bushel.

In the outside markets, the Brent crude oil market is 2.20 dollars per barrel lower, the U.S. dollar is higher, and the Dow Jones Industrials are 38 points higher.

Jack Scoville, The PRICE Futures Group's Senior Market Analyst, said a few things are moving the markets on Wednesday.

"The weather is a big fundamental, and the forecasts for hot and dry this weekend is creating the fundamental reason to buy," Scoville added.