The Labor Department will report on the February payrolls numbers on Friday at 8:30 a.m. The unemployment rate is expected to stay at 4.6%, while average hourly earnings are expected to rise 0.3%.

"The 'whisper number' for payrolls seems close to 50,000, half of the consensus expectation," said Drew Matus, an economist for Lehman Bros. "Anything above 100,000 would be considered a strong number."

Matus, who's forecasting gains of 130,000 for February after 111,000 in January, has one of the highest forecasts on the street. He said there's a "general view" among traders that the number will be lower.

Most of his peers believe hiring was sluggish. Both the underlying fundamentals of slowing growth and the particulars of last month's weather point to one of the weakest payroll gains of the recovery.

February payrolls are the toughest of any month to forecast accurately, said Ray Stone, chief economist for Stone & McCarthy Research, in his preview. The weather and seasonal gyrations in retail and other sectors can lead to some wild, unexpected swings.

"We regard the downside risk to our [110,000] payroll forecast as more pronounced than the upside risk," Stone said.

The weather could be a big factor. January was one of the warmest Januarys in U.S. history. And the survey week was unusually dry, keeping many seasonal workers on the payrolls deep into the winter months. But February was cold and wet in much of the nation. A big storm lashed the upper Midwest and Northeast during the week of the government's monthly payroll survey.

The average temperature in the February survey week was 9.5 degrees colder than the average temperature in the January survey week, Stone said.

"The arrival of winter weather conditions across parts of the nation will lead to a well-below trend rise in payrolls," wrote David Greenlaw and Ted Wieseman, economists for Morgan Stanley, who are predicting payroll gains of just 40,000. They expect "a significant job loss" in construction industries of 50,000.

Stone expects construction payrolls to decline by 40,000.

Construction payrolls grew by 10,000 in December and 22,000, boosted, some say, by the warm weather in those months. Construction payrolls soared by about 1 million over the four-year housing boom.

Steve Wieting, an economist for Citigroup, expects the housing slump to lead to big layoffs, but not quite yet. "We believe a weak homebuilding season in the spring will generate greater weakness than seen so far," he said. He expects housing and related industries to shed 50,000 jobs a month during the second quarter.

David Rosenberg, chief North American economist for Merrill Lynch, expects as many as 900,000 job losses in housing and related fields this year. See full story.

There are also fundamental reasons to think hiring will be weak.

"Economic growth remains firmly below potential," said Daniel Jester, an economist for Moody's Economy.com.

Some of the recent data on the labor market have been weak:

Other indicators have been stronger: