Federal Reserve Chairwoman Janet Yellen said bad weather might explain the patch of soft economic data making headlines during the past few weeks, but she isn't quite sure.

The Fed's uncertainty on the matter likely puts its policy plans on cruise control for now, meaning continued reductions in monthly bond purchases unless the weak data persist and change the officials' view about the economic outlook.

"A number of data releases have pointed to softer spending than analysts had expected," Ms. Yellen told members of the Senate Banking Committee on Thursday. "That may reflect in part adverse weather conditions, but at this point it is difficult to discern exactly how much."

Ms. Yellen, who became the Fed's leader at the beginning of the month, will oversee her first policy meeting in less than three weeks.

The Fed has reduced its monthly bond buys by $10 billion at each of the last two meetings, to $65 billion most recently. Her comments suggested the Fed will likely trim them again to $55 billion at the next meeting, March 18-19.