Those looking for a rapid uptick in the U.S. economy probably will have to tone down their expectations, at least for now.

In the near term, growth projections, at least by the top-line measurement of gross domestic product, are looking a whole lot more tepid than they did a few months ago.

GDP, which measures the sum of goods and services in the economy, is likely to have increased just 1.2 percent in the first quarter, according to the Atlanta Fed's closely watched GDPNow model. That's below the 1.5 percent projected by CNBC's Rapid Update forecast.

While much of the market has been focused on increased growth expectations under the Trump administration, GDP numbers have been sinking rapidly, in a precipitous though somewhat stealthy manner.

As recently as Feb. 3, the Atlanta Fed was projecting 2.7 percent growth for the first three months of 2017. But a steady flow of disappointing numbers, from production to construction spending to trade, has pulled down the estimate.

Those numbers have stood in stark contrast to sentiment surveys from businesses, investors and consumers, as well as purchasing managers and others at the corporate forefront. That in turn has produced some severe head-scratching from market professionals.