* Corn, soy prices buck USDA forecasts for massive U.S. harvest
* Increased export outlook, storm damage encourage short-covering
* Wheat rises on corn rally, Egypt tender eyed
CHICAGO, Aug 13 (Reuters) - Chicago corn prices surged to the highest level
in nearly three weeks on Thursday as worries over storm damage in the U.S.
Midwest countered pressure from huge government harvest forecasts, while
soybeans climbed to a 10-day high amid brisk export demand.
The rally added strength to wheat, too, despite ample global supplies
weighing over the market.
In widely followed monthly forecasts, the U.S. Department of Agriculture
(USDA) said on Wednesday U.S. farmers would reap a record corn harvest and a
second-biggest soybean crop, buoyed by favorable weather.
However, selling pressure was limited after prices already touched
multi-week lows in the past few days. The market was also assessing the impact
of Monday's derecho storm, which came after the Aug. 1 cut-off point for crop
conditions used by USDA for its August forecasts.
The storm potentially impacted some 10 million acres of farmland in Iowa,
the top U.S. corn growing state, according to state authorities.
USDA reported on Thursday that Chinese buyers booked deals to buy 197,000
tonnes of U.S. soybeans, the seventh weekday in a row that the government has
reported a sale to the world's top buyer of the oilseed.
The most-active corn contract on the Chicago Board Of Trade was up
3.13% at $3.37-1/2 a bushel at 1533 GMT.
Traders said a recent slide in corn, which led the European Union this week
to re-introduce a corn import tariff, also was helping to fuel Thursday's price
rally for U.S. supplies.
CBOT soybeans rose 1.93% to $9.00 a bushel, but earlier had climbed to
$9.00-3/4 a bushel, the highest since July 27.
CBOT wheat rose 1.42% to $4.98-1/4 a bushel.
The wheat market was awaiting the outcome of a second import tender this
week by Egypt, expected to confirm the competitiveness of Russian supplies.
(Additional reporting by Gus Trompiz in Paris and Naveen Thukral in Singapore;
Editing by Rashmi Aich, David Evans and Sonya Hepinstall)