Cash registers are jingling - but will they next year?

You wouldn't know it by the throngs jamming Saks Fifth Avenue or R.H. Macy's. ``Top Gun'' jackets are, well, flying off the shelves. And video products are hotter than klieg lights. But early tallies indicate department store sales are soft this month. And several Wall Street elves are crossing retail stocks off their stocking-stuffer list.

Robert J. Simonson, an analyst with Kidder, Peabody & Co. in New York, recently scratched nearly a dozen names.

``The weak Christmas sales are a precursor to a more cautious consumer,'' he says. ``Retail sales are going to be slower next year. There just plain aren't going to be a lot of stocks that do well in the first half.''

During the first fortnight of December, retail sales were up just 1.3 percent over the same period last year, according to the widely followed Johnson Redbook Service, a subsidiary of Prescott, Ball & Turben, a Cleveland-based brokerage. Author Edward Johnson had expected sales this month to be 5 to 6 percent higher than last December.

``With each week that goes by, it looks tougher to meet that forecast,'' Mr. Johnson concedes.

Not surprisingly, retail stocks have not been stellar performers of late. Nor has the Dow Jones industrial average. Last week, sellers focused on huge layoffs at AT&T and another sluggish sales report from IBM. The bellwether index closed Friday at 1,928.85, up 16.59 points for the week.

Still, 1986 has been a strong year for retailers. The 6 to 7 percent full-year sales gains, with almost no inflation, are nearly double the historical trend. But with investors oriented toward the future, 1986 will be a hard act to top.

``Many retailers have unsustainably strong pretax operating margins - the strongest in six years,'' says Mr. Simonson. ``That's going to make earnings comparisons more difficult next year.''

The current sales mushiness, Simonson contends, is predicated on the spending boom before December. In October and November, consumers shopped with a passion. Auto sales soared on cut-rate financing deals. And boats, refrigerators, and electronics buying surged as people rushed to take advantage of the sales tax deduction before the law changes on Jan. 1.

But given the high consumer debt levels, the sales pace of 1986 will be ``unsustainable'' in 1987, Simonson says.

All too much humbug for Fred Wintzer, a retail analyst at Alex. Brown & Sons, a Baltimore brokerage.

``I think we're going to see a huge last-minute surge,'' Mr. Wintzer says. ``We got off to a slow start due to bad weather just after Thanksgiving. But we've had cliffhangers in the past and pulled it out in the last three days. Before it's all over, Christmas will be prove to be OK.''

He says investor jitters are making retail stocks cheap, and ``this is one heck of a buying opportunity.''

Of course, Simonson at Kidder, Peabody doesn't buy such a buoyant prognosis. But the brisk sales of video cameras, digital disc players, and other electronic leisure paraphernalia have enabled Circuit City Inc. to stay on Simonson's wish list. He likes the company's management and an unusually successful advertising campaign.

In fact, Circuit City is something of a darling on Wall Street. Goldman, Sachs & Co. analyst Carl Balter expects earnings growth to exceed 50 percent in 1986 and 33 percent in '87. Last week, the electronics chain based in Richardson, Va., reported net income soared 128.5 percent in the quarter ending Nov. 30.

Toys ``R'' Us is another steadfast favorite among analysts. Toy sales are gaining momentum down the December stretch, and Standard & Poor's analyst Paul Valentine expects sales this month to be 6 to 8 percent above last year.

Despite his lackluster '87 outlook for retailers, Kidder, Peabody's Simonson is sticking with Toys ``R'' Us. He cites ``the supply problem. They can't get a lot of the hit toys, the Laser Tag or Teddy Ruxpins, in the kind of volume they need.'' Consequently, Simonson figures, demand for these products will spill over into next year.

Mr. Valentine offers another reason for keeping an eye on toy retailers. He says this is a comparatively slow transition year between the ebb of fantasy toys and the flow of high-tech toys.

``Next year I expect toy industry sales to be up 15 percent, perhaps as much as 20 percent,'' he notes. ``When fantasy hit its stride, industry sales shot up 20 percent, despite the [concurrent] collapse of video games. High-tech will hit its stride in 1987.''

Valentine dislikes the biggest toy cobblers. After previewing their 1987 line earlier this month, he concluded, the giants ``have lost their creativity and originality. They're not innovating.''

Valentine says these companies have been scooped by the small ones making laser guns and talking animals. Burned by the sudden passing of video games a few years back, the majors are too wary of high-tech now, he says.

Valentine says more-sophisticated talking dolls and a major American move into radio control (now dominated by Japan) are in the works. And yes, parents, the laser tag guns may be obsolete by next Christmas. One replacement is said to be a gun that shoots pellets of colored gunk 40 feet.