• by Sarah Mahoney  @mahoney_sarah, October 9, 2008

As more leading retailers posted gloomy September sales results on Thursday, industry experts are getting a grip on just how bad the next few months may be.

TNS Retail Forward, a consultant based in Columbus, Ohio, says September same-store sales growth weakened to 1.3%--with major retailers reporting a 2% decline from last month, using its sales-weighted composite. These weak results have deepened its conviction "that the coming months will be the weakest spending environment that the U.S. economy has faced in at least 17 years," it says.

While the value segment, drug stores and warehouse clubs held up well, apparel sales continued to get slammed, as consumers embraced their new "not shopping" ethic with a vengeance. At Gap Inc., overall comparable-store sales fell 11%, while the nightmare at Old Navy continued, with sales sinking 24%. At Chico's, sales tanked 15.6%. And at Limited Brands, sales at both its Victoria's Secret and Bath & Body Works chains fell 7%.

And while Aeropostale (up 5%) and Buckle (posting yet another impressive month, with sales up 19.7%) fared well, most teen retailers took it on the chin. Abercrombie & Fitch says its sales fell 14%, and warned investors that it will likely miss its financial targets. Sales at American Eagle Outfitters fell 6%, while Pacific Sunwear's sales slid 5% and Hot Topic sales fell 1.8%.

Perhaps more alarming, however, is Retail Forward's latest ShopperScape data, showing just how much consumers are planning to cut back in the months ahead. Its survey, which it says was taken before the financial crisis deteriorated at the end of September, finds that 29% of shoppers say they are planning to cut back on Halloween spending this year (last year at this time, only 21% of shoppers felt that way, and in 2006, only 17% planned to make cutbacks.)

And for the holidays, the scrimpfest is even more pronounced, with 37% planning to spend less on the holiday than they did last year, compared to 27% last year.

The changes are most pronounced among down- and middle-market shoppers, it says.

But the survey did find some solid bets for retailers: Consumers say they are least likely to cut back on gifts they buy for spouses and kids. The places they are most likely to cut? Gift-wrapping, greeting cards, indoor decorations and Christmas tree ornaments, as well as presents for friends and relatives outside the immediate family, holiday travel, and hosting parties.