Whether weather or the soon-to-expire federal home buyer tax credit, something drove home buyers to sign contracts in February: The National Association of Realtors reported Monday morning that its Pending Home Sales Index (PHSI) jumped 8.2% to 97.6 in February. That was 17.3% ahead of February, 2009 and well above analyst estimates of a decline of 1%.

"The rise in buyer contact activity may signal the early stages of a second surge of home sales this spring," said NAR chief economist Lawrence Yun."The healthy gain hints home prices are continuing to flatten,² he continued, adding. ³We need a second surge to meaningfully draw down inventory and definitively stabilize home values."

Results were mixed by region. The gains were partly driven by a surge of 21.8% in the Midwest, where the index increased to 97.9 and came in 18.7% ahead of February last year. The Northeast rose 9% to 77.7, 18.9% higher than February 2009. The South increased 9.2% to 107.0, up 17.5% year over year. The West fell 4.8% to 98.0 but remained 14.6% above a year ago.

Perhaps the most encouraging news in the Realtor report came via this quote from Yun: "Anecdotally, we're hearing about a rise of activity in recent weeks with ongoing reports of multiple offers in more markets, so the March data could demonstrate additional improvement from buyers responding to the tax credit."

The PHSI is based on a value of 100 set by the average level of contract activity during 2001. The index ended 2009 at 95.1, up from 87.2 in 2008 but behind the 2007 reading of 96.3.