U.S. corn futures soared to a record high Thursday as federal forecasters made unexpectedly deep cuts to supply outlooks.

Corn futures climbed 29 cents, or 3.8%, to $7.93 a bushel, eclipsing the previous high of $7.83 3/4 a bushel from April. The surge helped lift wheat and soybean futures at the Chicago Board of Trade.

Prices exploded after the U.S. Department of Agriculture, in a monthly crop report, slashed its domestic inventory estimate for the coming year 22% from May to 695 million bushels. Traders hadn't expected the sharp reduction as supplies for the current year were already estimated at a 15-year low.

The USDA indicated that foreign countries won't be able to offer much relief to grain users. The agency lowered its estimate for global corn supplies for the coming year by 13% to a five-year low of 111.9 million tons.

"Not only is the U.S. short of corn, so is the world," warned AgResource Company, an agricultural consultancy in Chicago.

Soft red winter wheat for July delivery recently traded up 3% to $7.70 1/2 a bushel, while soybeans for July delivery gained 0.4% to $14.07 a bushel