What Happened:

The Bureau of Economic Analysisannounced Wednesday that it had identified potential issues in its calculation of the country's gross domestic product.

The bureau seasonally adjusts its data to account for, among other things, inclement winter weather that can drag on economic performance. These adjustments, in theory, give economists a better idea of how the country is performing quarter to quarter by stripping out seasonal variables. But there may be some problems with how those adjustments have been made.

The bureau said Wednesday in a statement to U.S. News that it "is developing methods for addressing what it has found" and that recalculations would be available by July 30.

What It Means:

"What they're saying is, basically, the things that a number of people, including myself, have been talking about for a while. There seems to be a suspicious pattern that the first quarter in general seems to be weaker than the other quarter," says Brad McMillan, chief investment officer for Commonwealth Financial Network. "The whole point of seasonality adjustments is to normalize that. The past two years have really brought the issue to a head, and particularly just this past quarter."

The country's economy grew by an underwhelming 0.2 percent in the first quarter of 2015 and had the potential to be revised lower (potentially into negative territory) even before the bureau announced its calculation concerns.

And while McMillan says the GDP methodology alterations likely won't be groundbreaking, a 10th of a percentage point here or there could mean the difference between economic growth and contraction in a sluggish first quarter.

"It's not going to take it from 0.2 to 4.0, or, equally, it's not going to take it from 0.2 to -4.0," McMillan says, though he notes that "when growth is systematically lower, then it's a much bigger deal, relatively speaking."