Only about 60 percent of the Washington area's 1,500 filling stations are expected to be open this morning, and most will be closed by afternoon, American Automobile Association officials said yesterday. Some gas stations will open as early as 6 a.m.

At the same time, Maryland and District of Columbia officials took steps to ease the gas shortage Sunday, the day when most service stations have been shut in recent weeks. Officials announced that 26 filling stations would pump gas Sunday in the District and Montgomery and Prince George's counties. These stations will receive special "setaside" fuel allotments.

In Northern Virginia, the fuel outlook for Sunday appeared more uncertain. Virginia officials said they could not identify which gas stations in Northern Virginia, if any, had received additional fuel supplies for the weekend.

The Virginia officials said that 1,900 filling stations in the state had requested extra gasoline supplies on a "first-come, first-served" basis. "I would presume that [some Northern Virginia service stations] have received some extra gas," said Norman McTeague, operations officer for the Virginia State Energy Department. "I just don't know offhand."

Gasoline was reported in scarce supply along most northern and Mid-Atlantic sections of the East Coast. Fuel was said to be more plentiful along the southern part of the Eastern Seaboard, from central and Southside Virginia to Florida. Gas supplies were described by AAA officials as reasonably adequate in much of the Middle West, the West and the Southwest and in the most Southeastern states except for Louisiana.

"It's the tightest through New England and the Middle Atlantic states. It's tighter there than anywhere in the country," said Hank Downey, a national spokesman for the AAA, which released a nationwide survey of 6,833 service stations. A spot check yesterday be the Associated Press also reported that the most severe shortages appeared to be in the urban East.

Local AAA officials described their own forecast that about 60 percent, or approximately 900, of the Washington area's gas stations would be open this morning as only moderately reliable. "There's a caveat here. This [survey] was done Tuesday," said Bill Toohey Jr., a spokesman for the AAA's District of Columbia Division. The AAA conducts a weekly survey in an attempt to predict how many gas stations will stay open over the weekend.

Toohey described as "encouraging" the Maryland and D.C. moves to keep some service stations open on Sunday. The AAA's survey last Tuesday had indicated that only 5 percent - or 75 - of the area's 1,500 filling stations were then planning to pump gas on Sunday.

tAs the weekend and the July 4 holiday approached, lines grew considerably longer at gas stations yesterday than they had been earlier in the week. Train and bus company officials also said they were deluged with passengers and reservations.

"A lot of people are taking off work early to get gas before the weekend starts," said Vernon Crawford, manager of Carl's Sunoco on Pennsylvania Avenue SE. More than 30 customers were lined up to buy gas when Crawford shut off his pumps yesterday at 1:30 p.m.

"I only have 4,000 gallons left. Since I am getting a special allocation from the mayor, I have to keep my promise to open up on Sunday," Crawford said.

The District of Columbia's energy office announced that eight gas stations had been given "setaside" fuel to stay open from 8 a.m. to 1 p.m. Sunday. These stations, at scattered locations throughout the city, were the same ones that had opened with emergency allotments last Sunday. Officials conceded that their supplies might run out before 1 p.m.

City officials also said they plan to make public tomorrow a list of 10 gas stations that will be open from 8 a.m. to noon on Wednesday, the July 4 holiday. In addition, they said they will also announce locations of eight other stations that have agreed to operate from 7 p.m. to 9 p.m. on Monday, Tuesday, Thursday and Friday.

Amid concern over shortages, there were words of advice for would-be travelers and even a few bright notes. AAA officials suggested that travelers buy gas early in the morning, driver on interstate highways where many filling stations are reported open, and avoid looking for fuel on Sunday.

The Virginia State Travel Service made available a survey of filling stations along interstate highways crossing in the state. It indicated that today 42 percent of the gas stations would be open on I-95, 78 percent on I-81, 78 percent on I-64, 76 percent on I-85, 100 percent on I-77 and 44 percent on I-66. On Sunday, the survey showed, 27 percent would be open on I-95, 56 percent on I-81, 23 percent on I-64, 72 percent on I-85 and 100 percent on I-77. No figure was available for I-66 for Sunday.

"There's a lot of negative talk about people not going anywhere," said District of Columbia AAA spokesman Toohey. But he added that some these fears were misguided. He recommended a weekend outing along Virginia's Skyline Drive and the Shenandoah Valley, where gas was reported readily available. "If people are looking for something to do, gas is good (there)," he said.

Toohey also suggested Maryland's Eastern Shore and the Virginia Beach, Norfolk and Williamsburg areas of Virginia as places to visit where gas supplies appeared sufficient. Ocean City, Md., officials, he noted, have urged motorist to buy gas en route to the beach resort, rather than in the town itself.

The stations that will be open on Sunday and their hours - when they could be ascertained - are :

Prince Georges County

BP Station 4810 Annapolis Road, Bladensburg; BP Station, 3290 Queen's Chapel Road, Hyattsville; BP Station 3210 Queen's Chapel Road, Mount Rainier; Sauber Enterprises, 16001 Indianhead Hwy., Accokeek (Sat. 8 a.m.- 6 p.m., Sun. 8 a.m.- 6 p.m.); Towne Center Shell, 13200 Laurel Bowie Rd., Laurel (Sat 6 a.m.- 9 a.m., Sun 9 a.m.- 1 p.m.); Shell Station, 8309 Annapolis Rd., New Carrollton (Sat. 6 a.m.-9 a.m., Sun. 4 p.m.-6 p.m.); Wade's Gulf, 6100 Oxon Hill Rd., Oxon Hill (Sun. 6 a.m.-10 a.m.); Mitchellville Exxon, Rtes. 301 and 50, Mitchellville (Sun. 8 a.m.-noon), and Hampton Mall Exxon, 8901 Central Ave., Capital Heights.

Montgomery County

Kenwood Mobile, 5201 River Rd., Bethesda (Sun. 7 a.m.-11 a.m.); Sullivan's Bethesda Mobile, 7100 Wisconsin Avenue, Bethesda (Sun. 9 a.m.-1 p.m.); Colonial Shell, 4101 Randolph Road, Wheaton; Damascus Shell., 26300 Ridge Rd., Damacus (Sat. 9 a.m.-6 p.m., Sun 10 a.m.-4 p.m.); Germantown Gulf, 19815 Germantown Rd. (Sun. 8 a.m.-noon); Parklawn Rexaco, 11800 Parklawn Dr., Rockville Shady Grove Rd., Gaithersburg (Sat. 8 a.m.-2 p.m.; Sun 8 a.m.-2 p.m.); Aspen Hill Amoco, 13800 Georgia Ave., Silver Spring (Sun. 11 a.m.-2 p.m.; and Calverton Amoco, 22 Randolph Rd., Silver Spring.

District of Colombia

(Hours 8 a.m. to 1 p.m.)

Lindsay Patrick Amoco, 814 Bladensburg Rd. NE; Carl's Sunoco, 2510 Pennsylvania Ave. SE; Lloyd's Exxon, 415 Rhode Island Ave. NE; Steven's Exxon 5831 Georgia Ave. NW; L Street Exxon, 1100 13th St.; Colonial Exxon, 3327 M St. NW; Parker Gulf, 1200 South Capitol S. SE, and Morin and Captain Amoco 4300 Connecticut Ave NW. CAPTION: Chart, Holiday Gasoline Guide, The Washington Post