Here we go again? Another spring is here and suddenly the economic data is looking weak again. Private-sector nonfarm payrolls rose in March by a slim 121,000 on a seasonally adjusted basis. That’s roughly half as strong as we’ve been seeing in recent months. In February, for instance, private job growth was a much stronger 233,000. It’s safe to say that today’s number is a big disappointment and far below what most economists were expecting. Today’s jobs report also raises new concerns that the economy is weaker than it appeared in recent months, giving new strength to the arguments that the warm winter has been artificially juicing the numbers.