CHICAGO, Aug 5 (Reuters) - U.S. corn and wheat futures ticked higher on Wednesday, supported by a round of bargain buying and short-covering after posting sharp declines a day earlier, traders said.

Soybean futures weakened to their lowest since July 14, with forecasts in key growing areas of the U.S. Midwest calling for rains that will shepherd the crop through critical stages of development weighing on the market.

The gains in corn and wheat were limited by expectations that supplies of both crops will remain burdensome.

"The grains had nowhere to go but up this morning after an ugly finish yesterday," Matt Zeller, director of market information at StoneX, said in a note to clients "Massive U.S. crop prospects remain the elephant in the room."

At 11:17 a.m. CDT (1617 GMT), Chicago Board of Trade September soft red winter wheat was up 1-1/2 cents at $5.09-3/4 a bushel.

There were no U.S. offers listed in the latest Egyptian tender for wheat.

Traders were also assessing disruption to wheat supply in Lebanon after a deadly blast at Beirut port destroyed a major grain silo.

CBOT December corn was 1-1/2 cents higher at $3.21-3/4 a bushel, with bargain hunters drawn in after the contract made a new low on Tuesday.

Chart support levels and a sharp fall in the dollar against a basket of currencies helped grain futures to steady, but analysts saw limited immediate upside to prices.

"The market is running out of time for any weather event to curb the huge prospective U.S. crop," said Tobin Gorey, director of agricultural strategy at Commonwealth Bank of Australia.

CBOT November soybeans were down 4-1/2 cents at $8.77-1/4 a bushel.

Traders shrugged off the U.S. Agriculture Department's announcement of a sale of 192,000 tonnes of soybeans to China. (Additional reporting by Gus Trompiz in Paris and Naveen Thukral in Singapore; Editing by Rashmi Aich, Jane Merriman and Jonathan Oatis)