Porcelli notes that some activity measures like the Philadelphia Fed index legitimately could be written off as bad weather. But others, such as nonfarm payrolls, the Institute for Supply Manufacturing, retail sales and even housing sugest that something more fundamental is at play. Moreover, parts of the economy that really should have taken a weather hit, such as construction hiring, actually improved, while weather-resistant areas like online shopping deteriorated.
That doesn't mean that a significant downturn is coming—just that expectations may have outpaced reality.
"This weakness is merely a reversion to the mean following rates of growth that, given the fundamentals of the U.S. economy, were never sustainable to begin with," Porcelli said.
Indeed, several economists have cut what had been fairly robust expectations for first-quarter growth after the inventory-fueled jump of 4 percent in the fourth quarter of 2013. JPMorgan, for instance, reduced its outlook from 2.5 percent to 2 percent, though Wall Street forecasts still maintain a solid year is ahead.
As for the market, investor sentiment has seesawed.
(Read more: Weather taunts traders betting on regaining highs)
January's pullback led to February's profit as traders stepped in to buy the dips.
Further deterioration in the economic data might make the Federal Reserve rethink its decision to reduce its monthly bond-buying program—quantitative easing—in $10 billion-per-meeting increments, a possibility for which traders seem to be preparing.
"We believe that the market is pricing in a longer QE program. This is consistent with the steepening of the difference in yields (between 5-year notes and 10-year notes), the rise in gold prices, decline in term premium and the negative correlation between equities and rates," Bank of America Merrill Lynch rate strategist Priya Misra and the rest of the firm's fixed income team said in a note to clients. "Note that equities are back to their highs ... (which) would be consistent with the market pricing in some chance of the Fed not tapering in the March meeting."
Consequently, the Fed likely will be looking at next week's nonfarm payrolls data even more closely than usual. The news of late has been fairly awful, with December and January averaging just 113,000 net new jobs.
TrimTabs, which tracks market and economic data, said income tax withholdings have increased just 5.3 percent annualized, which it attributed more to "bonus shifting" from late 2013 into early 2014 than underlying payroll strength.
"In addition, credit indicators, unemployment claims data, housing data, and regional manufacturing data suggest the much-anticipated economic acceleration is nowhere in sight," TrimTabs CEO David Santschi said in his weekly report. "If the economy deteriorates or asset prices tumble, we expect the Federal Reserve to be quick to stop 'tapering,' much as it cranked up the printing presses soon after QE1 and QE2 ended."
(Read more: Stocks set for a big fall, thanks to the Fed: Grant)
That would be more likely to happen after realization hits that winter simply can't explain away the economic weakness.
"It may come as a shock to mainstream economists that it is cold and snowy in the Northeastern United States during the December-February time frame," economist Michael Pento said in an analysis. "However, worse than expected winter weather in certain parts of the U.S. cannot adequately account for stumbling GDP across the developed world and crumbling securities in emerging markets."
Pento ascribes the economic inconsistencies to a world trying to adjust to changing policies from the Fed and other central banks that have created uncertainty and misallocation of resouces across the globe.
"The resulting instability is causing dizzying swings in most markets and economies. Therefore, it is not the meteorological storm that is to blame for slowing global growth, but rather the destructive forces that result from the clash between the intensifying forces of inflation and deflation," he said. "The historic magnitude of these boom and bust cycles are directly caused by the unprecedented manipulation of markets by world governments."
—By CNBC's Jeff Cox. Follow him on Twitter