The third round of layoffs at USAir Group Inc. is just the latest note in an increasingly dismal drumbeat of dismissals at Washington area companies.

Washington in 1990 is on its way to becoming what Detroit was in the early 1980s, Houston was in the mid-1980s and Boston and New York were in the late 1980s: a city with too few jobs and too many job-hunters.

"I think this area is going to suffer quite a bit," said Thomas J. Schneider of Restructuring Associates Inc., a Washington firm that helps troubled companies.

For now, the metropolitan area still has virtually the lowest unemployment rate of any major city in the nation, 3.3 percent as of June, the latest month for which figures are available. But the rate has risen considerably since its low point of 2.4 percent in December 1989, and more increases are expected as already announced layoffs show up in the figures.

"It seems like there is one coming every day," said Richard Groner, chief of labor market information for the D.C. Department of Employment Services.

The list of names of local companies that have announced layoffs or job eliminations recently reads like a roll call of blue-chip Washington: USAir, a total of 3,600; Fantle's drugstores, 2,000; Garfinckel's, 900-plus; MNC Financial Inc., 400; Questech Inc., 200; Washington Bancorporation, parent of National Bank of Washington, 150; Perpetual Savings Bank, 200; Chevy Chase Federal Savings Bank, 100-plus.

There are reports that other area layoffs, in the hotel and banking industries, will be announced shortly. Claims for unemployment compensation are up in all three local jurisdictions, and figures indicate the average duration of joblessness has begun to rise.

USAir officials did not know how many of the announced layoffs, either the earlier group or yesterday's, would be in the Washington area. But they are likely to further damage the region's slowing economy regardless. As layoff announcements make consumers more fearful of losing their own jobs, spending on goods and services will fall further -- leading to even more layoffs.