The economy is expanding 3 percent, but that's "getting masked" by the stormy and cold winter weather, says Mark Zandi, chief economist of Moody's Analytics.

"Nothing changed in December, January fundamentally," he told CNBC.

The weather has been a "mess, and it's been like this for a couple of months," Zandi said. "It's really starting to affect the data."

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But Zandi wasn't displeased with the 175,000 January private-sector payroll gain in Wednesday's report prepared by ADP and Moody's.

That number signals a "3 percent economy, and it's a 175,000 to 200,000 monthly payroll gain [economy]," he said.

Others saw the number in a positive light too.

"There’s a lot of uncertainty on the weather effect but the broader message from ADP is that the trend in private payrolls remains pretty solid," Jim O’Sullivan, chief U.S. economist at High Frequency Economics, told Bloomberg.

"Consumer spending can sustain a reasonably healthy pace.”

The government jobs report for December included a paltry 74,000 payroll gain, which many economists said was limited by weather.

Financial markets are now riveted on Friday's release of the January report. Economists surveyed by Bloomberg forecast a median 188,000 payroll increase.

"I don't think we got any weather bounce back in January, but I don't know weather was playing as big a role" as it did in December, Zandi said. "I bet you a year from now when we get all the revisions in it won't be 74,000 [for December]. It'll be 174,000."

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