Gov. Harry Hughes today defined the fiscal dilemma facing the Maryland General Assembly this year by confirming that he has not yet found the money to cover several major programs he thinks should be included in the state budget.

In a press conference on the eve of the opening of the three-month legislative session, Hughes said he will submit a budget to the assembly next week that omits pay raises for state employes, increases in welfare benefits and targeted education aid to local subdivisions, even though he believes these items should not be scrapped.

Hughes indicated that the major task of the legislative session would be to figure out how to pay for the missing programs without raising taxes.

"We have no plans as of this point as to where we're going to get some additional fund," Hughes said. "We're continuinig to look at where we can get relief . . . but it may take some time for that to jell."

In a style that reflected the uncertainty surrounding state finances, Hughes repeatedly declined to take a position on any of several money-raising measures that he and legislative leaders have discussed privately in the weeks leading up to the session.

Most notably, Hughes seriously has considered reducing state aid that has enabled county governments like Prince George's to cut taxes without deleting services. Today, he insisted that although there is "some sentiment in the legislature to do this . . . there has been no decision."

Regarding another stopgap proposal -- this one by a legislative subcommittee -- to raise $20 million to $50 million by increasing fees for trucks that use Maryland's highways, Hughes said: "I never said that shouldn't be considered." He added that he has not yet read the proposal.

Hughes said he has put off a decision on these and other measures in part because of the possibility that the state's fiscal experts, who discovered the revenue crisis last fall, might be more optimistic when they next meet in March.

Hughes said he hopes the fiscal analysts will conclude at that time that state tax revenues are growing faster than they have so far predicted, thus providing the lawmakers with a windfall to finance the missing programs without controversial local aid cuts. Hughes cautioned that he is "not optimistic" that Maryland's fiscal picture will brighten before the legislature enacts the budget, which by state law must be balanced.

In the first of what is likely to be a continuing series of difficult acknowledgements of funding priorities, Hughes said he would look first for the money to raise state employe salaries. He said that the increased welfare benefits and the $8 million targeted aid program for education that he would like would have to wait.

Noting that employe salaries have increased by only 13 percent in the first two years of his administration, Hughes said, "It's a high priority. There's no question that at the state level we're having difficulty competing, salary-wise."

The governor also said he plans to introduce legislation to cut back state Social Security payments by several million dollars by eliminating benefits for employes who are on sick leave.

Hughes also announced the formation of a task force to trim state medicaid costs, which already have been curtailed once this year with measures that included a 20-day limit on hospital visits by medicaid patients.

Administration officials said the state funds Hughes had included in his new budget for the medicaid program may fall as much as $15 million short unless the task force approves additional cutbacks.

Underlining the predominance of budget concrens in this session, Hughes cited only four other measures that he plans to include in his 1981 legislative package. The most ambitious of these would create a state energy authority to channel U. S. grants and state funds to a wide spectrum of energy conservation projects, and would toughen the state's drunk driving laws.