Most experts believe the central bank will raise interest rates just once more this year, but a faster economy or an increase in wages or inflation could prompt policy makers to move more quickly to tighten monetary policy and shrink the Fed’s balance sheet in 2018.

Janet L. Yellen, the Fed chairwoman, and other policy makers will also be closely watching data expected on Friday morning from the Labor Department on hiring, wages and unemployment in August. Economists estimate that the economy added 180,000 jobs, but a stronger gain, like July’s 209,000 jump, or an uptick in wages, would focus more investor attention on the Fed’s next meeting on Sept. 19 and 20.

At a speech last week in Jackson Hole, Wyo., Ms. Yellen focused mostly on the continuing need for regulation, rather than the outlook for growth, but she did term the current economy “strong.”

On Wednesday, some economists offered improved expectations for job creation in August after the payroll processor ADP reported that private employers added 237,000 jobs, well above the 185,000 increase that had been expected.

The acceleration in spending suggests that a so-called Trump bump — improved sentiment among consumers and more optimism among business leaders — may be translating into concrete actions like homeowners buying new appliances and companies investing in new software or equipment.

“The consumer is in the driver’s seat in terms of economic growth,” said Scott Anderson, chief economist at Bank of the West in San Francisco. “It puts us on a stronger path going into the third quarter, although Hurricane Harvey introduces some uncertainty.”

Mr. Anderson expects growth in the range of 3 to 3.5 percent in the current quarter, but he said the hurricane could shave as much as 0.3 percentage points off that figure. A hit like that would mostly be reversed in the year’s final quarter as rebuilding efforts kicked in, he added.