WASHINGTON — Straddling risky economic crosscurrents, the Federal Reserve is expected to stand still this week on interest rates.

The chairman of the Fed, Ben Bernanke, and his colleagues, who open a two-day meeting today, are in a tricky spot: they are faced with stuck-in-a-rut economic growth along with inflation threats from rising prices for energy, food, and other commodities. Fed officials have made clear that because of concern about inflation, they’re not inclined to cut rates further. At the same time, they have recognized that pushing rates up too soon could undermine an economy buffeted by housing, credit, and financial woes.

“These are very challenging waters to have to navigate,” an economist at Argus Research, Richard Yamarone, said.

Against that backdrop, the Fed is almost certain to hold its key interest rate steady at 2% when it wraps up its session tomorrow. If that’s the case, the prime lending rate for millions of consumers and businesses would stay at 5%. The prime rate applies to certain credit cards, home equity lines of credit, and other loans. Wall Street investors and a few economists believe inflation problems might force the Fed to start boosting rates in August or later this year. Others think that’s a situation the Fed would like to avoid — especially given that the housing market is still flailing and foreclosures are at record highs.