Retailers may not see upturn until the holidays.

April showers brought May flowers retail-wise, as May industry sales jumped 3.8 percent from that month a year ago, but the forecast for the rest of the year is hazy, economists say.

According to the National Retail Federation's chief economist Rosalind Wells, the economy got a healthy shot in the arm when consumers received tax rebate checks last month.

Looking ahead, however, things may be slow for local retailers at least until the holiday shopping season.

Alan Gin, associate professor of economics at the University of San Diego, says numerous factors are at play.

"Certain categories are being affected more than others because of the housing slump, including retailers of furniture, household appliances and home improvement items," Gin said.

In Gin's opinion, the automotive industry has been affected the most, and that will continue as gas prices remain on the rise, he says.

"Consumers have less equity to draw from in terms of home equity loans, and if you haven't lost your home to foreclosure, you're having to pay a higher mortgage because of adjustable rates," he said.

As for back-to-school spending, gas prices continue to muck up prospects for much improvement.

"My sense is that retail sales still will be affected by the time the back-to-school period begins," Gin said.

Gas is up by about 45 percent from last year, and by Gin's estimates, that's taking about $100 million per month out of the Meal economy.

"People are spending that chunk on gas rather than going to the movies or out to dinner," said Gin.

Adding a weaker U.S. dollar to the equation means less imported goods and higher prices domestically, he added.

Gin predicts that Christmastime will mark the beginning of a slow turnaround.

"I do expect the dollar to regain its strength at the year's end, and interest rates will rise again," Gin said.

The NRF's Winter 2008 Retail Outlook report suggests better times ahead for retailers.

According to the report, industry sales are expected to be up to a 3.8 percent increase for the second half of the year, compared with an estimated 3.2 percent gain in the first half of 2008. For the year, projected industry sales are projected to increase 3.5 percent.