March corn was trading 8 1/4 cents higher late in the overnight session. Outside market forces look slightly positive today with a weak US dollar. Without a shift in the weather pattern in South America, traders remain concerned over the possibility of seeing even more losses to the Argentina crop than what have been seen so far. A decent rain event this week should ease stress with 1/2 to 1 1/2 inches of rain in the next few days covering 80-90% of the growing region. However, there is not much in the way of follow-up rains, and traders are concerned that the crops will be back in a stressful condition in another week or so. March corn closed unchanged on the session Friday after choppy and two-sided trade, and this left the market down 3 cents for the week. Traders were looking for significant rains for Argentina and southern Brazil for Tuesday of this week, but Thursday night models were not as wet as Wednesday, and this helped to provide underlying support. High temperatures ahead of the rain are expected to do additional yield damage. Weekly export sales, in the report released before the open on Friday, came in at 299,500 metric tonnes for the current marketing year and 6,500 for the next marketing year for a total of 306,000, which was below trade expectations. Cumulative corn sales stand at 60.7% of the USDA forecast for 2011/12 (current) marketing year versus a 5 year average of 52.3%. Sales of 453,000 metric tonnes are needed each week to reach the USDA forecast. Traders expect corn production in the US to be revised lower by about 45 million bushels for the USDA production report on Thursday, due to a revision lower in yield or even harvested acreage. Ending stocks are expected to be revised down by about 100 million bushels, compared with 848 million in the last supply/demand update. Traders see December 1st corn stocks down about 660 million bushels from the previous year. Stocks last year were 10.057 billion bushels. The Commitments of Traders reports as of January 3rd showed non-commercial traders were net long 204,303 contracts, an increase of 46,217 contracts for the week. The aggressive buying trend of the funds is seen as a bullish short-term force. Non-commercial and nonreportable traders combined held a net long position of 89,805 contracts, up 34,873. Commodity index traders held a net long position of 363,676 contracts, up 82. Traders see index fund rebalancing this week resulting in fairly aggressive selling of nearly 28,000 contracts.