NEW YORK May 30 (Reuters) - U.S. cotton futures rose for a second straight day on Friday despite weaker export numbers, and some traders said they expected prices to fall in coming sessions as wetter weather aids crop growth.

The most-active cotton contract on ICE Futures U.S., July , edged up 0.12 cent to settle at 86.27 cents a lb.

On Thursday, the contract had gained 1.28 cents, its most in a month, fueled by expectations that weekly U.S. cotton export numbers due on Friday would be bullish.

But that data turned out to be much weaker than thought, as net upland sales of all U.S. cotton stood at 61,000 running bales, down 83 percent from the previous week and 50 percent lower than the prior four-week average.

Traders had expected the U.S. Department of Agriculture to show a combined total of 200,000 bales booked for both the 2013/14 crop year and the new year beginning Aug. 1. A sharp increase in sales seen in the prior week's data shocked the market.

"Obviously there are some bulls who continue to hold to the theory that U.S. cotton is fairly priced at current levels," said Jobe Moss at cotton brokers Moss Capital Management in Lubbock, Texas.

"But it's inconceivable that the market can hold to such price levels with the type of export numbers we are getting and also the kind of good wet weather for cotton that the crop is experiencing," Moss said.

Cotton prices have been under pressure as rains have showered Texas, the top-producing U.S. state, and as the progress of plantings throughout the world's top exporter has picked up sharply.

"Weather will become a larger issue going forward," Sterling Smith, a futures analyst at Citigroup, wrote in a commentary on cotton on Friday. (Reporting by Barani Krishnan; Editing by Lisa Shumaker)