Woodward & Lothrop had sales at least 15 percent higher in the first quarter this year than in 1978, despite last winter's blizzard that shut its stores on George Washington's birthday, normally the beiggest day of sales for the year.

Woodward & Lothrop chairman Edwin K. Hoffman told stockholders at the company's annual meeting yesterday that because of the snowstorm, "profits were very severly affected as were sales." He said the stores were closed 30 hours during that period.

March proved to be a good month as was April, but final first quarter results were not yet available. "Sales increases have been good since the end of February," Hoffman said.

During interviews with reporters following the meeting Hoffman said sales for the quarter were "more than 15 percent" higher than the same period last year. Sales during the first quarter last year increased one percent from $54.7 million to $55.2 million over 1977, but profits decreased from $1.4 million (60 cents a share) to $1.2 million (51 cents a share).

Because this quarter's figures were not available, the board of directors delayed consideration of a dividend increase, Hoffman said.

Hoffman also announced, during the meeting, the election to the company's board of directors of former Washington, D.C. Mayor Walter E. Washington. Hoffman said that the company's board approached Washington for the slot, which was added just for him.

"There is no one in this city who better understands the relationship between business and the community than former Mayor Washington," Hoffman said.

Washington said he was "pleased" to be elected to the board because, "The company itself has had a good corporate policy," as far as civic projects and "it was good in times when we were having problems in the city."

Other new board members are store vice presidents Daviv P. Mullen and Robert J. Mulligan.

During a question and answer session Hoffman "guaranteed" that a woman would be named to the board by next year.

Hoffman also said following the meeting that he expects the Retail International Union's effort to organize the store's employes to fail when the question is put to a vote next month among the more than 6,000 workers in Woodies 16 stores two warehouses.

I expect we (the company) will probably prevail," Hoffman told reporters, although he added later that he was concerned.

"We're working day and night.We have a game plan," which he would not disclose.

Sources inside Woodies said that store supervisors are telling employees that the firm had been wrong in some areas and are asking that the employes give the company another chance. Hoffman said he had not directed any such action by the store's supervisors.

he AFL-CIO-affiliated union is seeking to replace the Independent Union of Woodward & Lothrop Employes, which has represented the department store chain's workers since 1940.

If the union wins, however, Hoffman said he has no way of forecasting what effects that will have on the company and its profits.

With concern over the energy situation, Hoffman said that the company is considering an energy plan that will consist mainly of more direct mail literature and advertisements that would allow sales by telephone or mail, "anything we can do to make sure that people can buy without getting in the car."

Hoffman said that the company is on target toward meeting its goal of sales of $400 million to $450 million by 1983. CAPTION: Woodies Chairman Edwin K. Hoffman With old and new logos: unfilling in the Os. By Robin Jareaux from photo by Margaret Thomas. The Washington Post