The Standard & Poor’s/Case-Shiller 20-city composite home price index, which will be released on Tuesday, likely rose 1.2% in July from the previous month, a Zillow Inc. (Z) forecast showed. The Case-Shiller, a key housing price index that covers 20 U.S. metropolitan areas, likely fell 4% in July from the year-ago period, Zillow said. The S&P/Case-Shiller 10-city index is expected to show the same month-over-month increase compared to June, while also registering a decline of 3.4% from a year earlier. “The market is full of conflicting signals right now with August consumer confidence down by 25%, July pending homes slipping, and the four-week moving average of mortgage applications also dipping,” said Zillow Chief Economist Stan Humphries in a statement. Humphries’ expectations for the Case-Shiller index were initially much weaker, but were bolstered recently by two indicators. The Zillow home value index, a key factor in its Case-Shiller forecast, rose 0.12% in July, and August home sales rose 7.7%, well ahead of expectations. Still, uncertainty is plaguing the market and will exert a drag on housing, according to Humphries. “I still believe that the continued fears about a Greek default, weak employment growth and low consumer confidence will ultimately translate into weaker housing performance in the back half of this year,” he said. “Looking ahead, expect fading monthly momentum in Case-Shiller.” Write to Liz Enochs.