It was not yet dawn yesterday when the first arrivals left the warmth of their cars and began forming a long line outside the Virginia Employment Commission office at Seven Corners, replaying a scene that has become depressingly familiar in the Washington area of late.

The December statistics for the Washington suburbs and the January statistics for the District of Columbia offered little encouragement to the men and women huddled in the cold waiting to apply for unemployment benefits and job-hunting assistance. And inside, struggling to cope with spiraling caseloads, those whose job it is to process and counsel the out-of-work were just as downcast.

"It's peaked up," reported Joe Smith, the unemployment insurance supervisor at the Seven Corners office. The staff there normally sees about 230 to 250 claimants a week this time of year. Last week about 380 showed up. Another 120 a day usually come in search of jobs, a figure that is putting a strain on both the facility and its personnel.

The generally rising unemployment rate has taken its toll on the jobless services provided by Virginia, Maryland and the District and left officials nervously monitoring sales taxes, mindful that people out of work translates into less revenue at a time when budgets are tight already.

Federal budget cuts have already forced officials in all three jurisdictions to make do with less. About 1,000 positions among the employment service staff people who help find jobs for the unemployed have been eliminated in the past few months.

In the Washington region, the unemployment rate for December was 5.2 percent or 85,300 out-of-work persons compared to 4.0 percent or 65,600 jobless for this same period a year ago. The District unemployment rate for January was 8.6 percent or 52,000 out-of-work compared to 8.4 percent in November and 7.2 percent during January a year ago.

In the Washington suburbs, Maryland officials reported that December unemployment, the most recent figures available, was 4.8 percent in Montgomery, Prince George's and Charles counties overall compared to 3.6 percent in December a year ago. Prince George's and Montgomery unemployment was 5.6 percent and 3.7 percent, respectively, down a tenth of a percentage point each compared to November but way above the 4.1 percent and 3.0 percent the two jurisdictions reported a year ago. Prince George's has about 22,000 unemployed residents while Montgomery has about 12,500.

Northern Virginia unemployment also dropped very slightly, from 4.0 percent in November to 3.9 percent in December, the most recent figures available. But that figure meant there were still 23,200 people unemployed compared to 17,800 a year ago when unemployment was 3.1 percent. In Fairfax County, about 10,428 people are unemployed while Alexandria has 3,629 jobless and Arlington has 4,202.

Looking ahead to what many predict will be an even shakier future, the officials warn that the unemployment services cutbacks and staff disruptions couldn't come at a worse time.

"It's been a zoo since the first of the year," said David Moates, the unemployment insurance supervisor for VEC's Alexandria office. He termed the caseload increases "dramatic" and "incredible" and said the staff cutbacks had caused a lot of confusion and upheaval.

"When you disrupt the staff that provides the service at a time the service is needed more than ever, you've got trouble," said Moates, whose office was slated to close but has remained open to process claims for unemployment benefits.

Virginia has closed 41 regional employment offices since last summer and abolished 788 positions, including 305 last month. Maryland expects to lay off 212 employment service counselors and other workers by Feb. 26 unless some of the federal cuts are restored. The District let go 46 temporary employes who worked at five facilities in the city.

The Reagan administration, which sought the cuts, and the Congress, which approved them just before the Christmas break, are now readying legislation that would restore some of the funds. But area officials were unsure yesterday how much money their jurisdictions might get and to what extent the new funds might ease their problems.

"The impact and the pressure has been very, very great," said Matthew Shannon, deputy director of program operations for D.C. Employment Services. He said the District attracts more claimants because it pays higher benefits ($206 a week compared to $140 for Maryland and $138 for Virginia), and he noted that the city has absorbed the largest portion of federal reductions in force (RIFS) and related layoffs in the private sector.

Maryland employment officials yesterday expressed some skepticism about whether unemployment had really remained unchanged from November to December, as state figures appear to indicate. They noted reports of increased caseload around the state and said the state has paid out a record $6 million a week in benefits for the last two months--a steady drain on the unemployment compensation fund. Legislation is now pending in the General Assembly that would bolster the fund by increasing the wage base on which employers now must pay unemployment insurance taxes.

Virginia and the District, which paid out $20 million and $9.3 million in benefits, respectively, in December, have already taken measures to increase the amount of money coming into their funds.

The effect of continued serious unemployment also has officials worried about the impact on future state revenues, particularly the sales tax. Maryland comptroller Louis Goldstein told legislative leaders yesterday he expects revenue estimates to remain the same but is nonetheless concerned about recent drops in the sales tax in January.

"Obviously, when people are not working, they're spending only what they have to spend," said Marvin Bond, assistant to the comptroller. "They're not buying, they're paying the rent."

But the situation that has officials worried the most is the one described by Moates at the Alexandria unemployment office. He said the once recession-proof town seems to be getting hit on all employment fronts, with no discernible trends or end in sight.

"It's across the board and the impact is dramatic and it's everywhere," Moates said. "It's the people who make the bricks and sticks, the people who sell the bricks and sticks and the people who sell gas to the guy who drives the truck to deliver the bricks and sticks."