* Chicago corn, soybean futures down more than 11% this week * Expectations of crop-friendly weather in parts of U.S. Midwest weighs (Adds quote in paragraph 3, fund positioning) SINGAPORE, June 18 (Reuters) - Chicago corn and soybean futures rose on Friday, but both the markets were set for deep weekly losses as forecasts of cool and wet weather in parts of the U.S. Midwest pressured prices. Wheat was poised for a second week of declines, weighed down by an advancing U.S. harvest. “U.S. weather is looking good and there is demand destruction at these high prices, which is going to limit the upside potential,” said one Singapore-based grains trader. The Chicago Board of Trade December corn added 0.9% to $5.37 a bushel as of 0435 GMT, while November soybeans were up 1.8% at $12.75-3/4 a bushel. For the week, both soybeans and corn were down more than 11%. Traders expect showers to bring relief to dry areas of the crop growing areas in the U.S. Midwest over the next two weeks, improving production prospects. Argentina’s 2020/21 corn yields continue to come in higher than expected as harvesting progresses, the Buenos Aires Grains Exchange said on Thursday, a week after citing ample yields as the reason for raising its crop forecast to 48 million tonnes. Wheat rose 1.2% to $6.46-1/2 a bushel after losing 3.6% on Thursday. The market was down 5% for the week. Commodity funds were net sellers of Chicago Board of Trade corn, soybean, soyoil, wheat and soymeal futures contracts on Thursday, traders said. (Reporting by Naveen Thukral; additional reporting by Colin Packham in Canberra; Editing by Aditya Soni) Our Standards: The Thomson Reuters Trust Principles.