* Hot, dry weather in United States supports grains prices
* Grains also underpinned by dollar fall after U.S. inflation data
* Grain market sees adjustments before Friday's USDA report
CHICAGO, Aug 11 (Reuters) - Chicago wheat and soybean futures closed higher on Thursday as a weaker U.S. dollar lent support to dollar-priced commodities and traders squared up their positions ahead of a key government report.
Meanwhile, corn futures firmed, supported by concerns about hot and dry weather stressing the U.S. Midwest crop through its final stages of development.
The most-active corn contract on the Chicago Board of Trade (CBOT) settled the day up 9-1/4 cents at $6.27-3/4 a bushel, while CBOT wheat added 11 cents to end at $8.10-3/4 a bushel.
Soybeans rose 20-3/4 to $14.48-1/2 a bushel.
Parts of the U.S. Midwest received rain in recent days, but heat in the western regions of the farm belt is expected to continue stressing crops, including soybeans going through a key growth phase.
Such dry, hot weather is raising investor uncertainty about crop yield risks ahead of the U.S. Department of Agriculture's monthly World Agricultural Supply and Demand Estimates report, set for Friday.
The government is expected to trim its outlook for U.S. corn production, according to a Reuters survey of analysts.
But the question will be how much the government will lower those numbers, in a report that has fueled volatile market moves in the past, said Joe Vaclavik, president of Standard Grain.
In 2019, corn futures prices posted their biggest drop in three years after USDA estimated a bigger-than-expected crop https://www.reuters.com/article/us-usa-grains-tour-threat/farmers-threat-prompts-u-s-agriculture-department-to-pull-staff-from-crop-tour-idUSKCN1VB242 on Aug. 12, despite floods that slowed planting that season.
USDA’s reports https://www.reuters.com/article/us-cbot-grains-braun-column/will-the-latest-usda-data-be-the-most-shocking-of-the-year-braun-idUSKBN2BT32J have long been a key reference for global commodities markets, and over the last decade, the most-active corn and soybean futures have moved sharply on USDA report days that coincided with the August reports.
"Going into harvest, it's all a matter of what size these crops are going to be," said Don Roose, president of Iowa-based U.S. Commodities. (Reporting by P.J. Huffstutter in Chicago Additional reporting by Gus Trompiz in Paris and Naveen Thukral in Singapore; Editing by Marguerita Choy and Matthew Lewis)
