Experts fear that a new wave of foreclosures will hit this year as prolonged unemployment makes it difficult for millions of homeowners to pay their mortgages — and many of them aren’t likely to get much help from a federal program aimed at keeping them in their houses. Banks participating in the Home Affordable Modification Program, announced a year ago this week by President Obama, have been slow to turn temporarily reduced mortgage payments into permanent ones. “The overarching sense is that the mortgage modification process has not worked that well,” said Bert Ely, an independent banking consultant.