The September S&P/Case-Shiller (SPCS) data out this morning showed more slowing in the housing market, with annual growth in the 20-city index falling 0.7 percentage points from August’s pace to 4.9 percent in September. This is the first time annual appreciation for the 20-city index has been below 5 percent since October 2012. The national index was up 4.8 percent on an annual basis in September.

Our current forecast for October SPCS data indicates further slowing, with the annual increase in the 20-City Composite Home Price Index falling to 4.3 percent.

The non-seasonally adjusted (NSA) 20-City index was flat from August to September, and we expect it to decrease 0.4 percent in October. We also expect a monthly decline for the 10-City Composite Index, which is projected to fall 0.4 percent from September to October (NSA).

All forecasts are shown in the table below. These forecasts are based on the September SPCS data release and the October 2014 Zillow Home Value Index (ZHVI), released Nov. 20. Officially, the SPCS Composite Home Price Indices for October will not be released until Tuesday, Dec. 30.

This month’s (September) SPCS release showed a brief uptick in monthly appreciation, to 0.3 percent for both of the seasonally adjusted (SA) composite series, although annual appreciation continued its slowdown. We expect the 10-City Composite (SA) to rise slightly (0.2 percent) from September to October, and the 20-City Composite (SA) to rise at the same rate. We expect annual appreciation to fall 0.7 percentage points from September to October for both indices.

The September Zillow Home Value Index was up 6.4 percent annually in October, down from a post-recession high of 8.3 percent recorded in April. The rate of annual appreciation has fallen every month since April, and we expect the slowdown to continue into 2015. The October Zillow Home Value Forecast calls for a 2.4 percent rise in home values from October 2014 to October 2015, less than half the rate of appreciation experienced in the past year. Annual appreciation in the national SPCS seasonally-adjusted series peaked at 10.9 percent in October 2013, and has fallen every month since December 2013. Further details on our forecast of home values can be found here, and more on Zillow’s full October 2014 report can be found here.

More on the differences between SPCS and ZHVI can be found here. Our commentary on the revisions to the national S&P/Case-Shiller Index can be found here.