Today, the S&P/Case-Shiller Home Price Indices showed that the non-seasonally adjusted September 10- and 20-City Composite rose 2.1% and 3.0% on a year-over-year basis, in line with Zillow’s forecast released last week. On a seasonally adjusted monthly basis, the 10- and 20-City Composites rose 0.3%  and  0.4% from August to September. The table below shows how our forecast compared with the actual numbers.

“September will likely be the last hurrah for Case-Shiller in 2012 in terms of monthly gains. We expect the monthly numbers to be negative for the balance of the year, due to seasonality and increased prevalence of foreclosures in the sales mix” said Zillow Chief Economist Dr. Stan Humphries. ” This shouldn’t, however, be a cause for concern as the Case-Shiller indices will still end the year up more than 3 percent from year-ago levels, clear evidence of a durable housing recovery. Hopefully lawmakers will cooperate in keeping the housing market on track by successfully navigating the fiscal cliff.”

Our forecasting model incorporates previous data points of the Case-Shiller series, as well as Zillow Home Value Index data and national foreclosure re-sales. To see how Zillow’s forecast of the August Case-Shiller indices compared, see our blog post from last month.