What was going on when I was born?

U.S. reconnaissance planes are providing almost instant intelligence on rebel movements before and during combat operations, according to the commander of Salvadoran forces battling insurgents in the eastern part of the country. Washington has said the reconnaissance missions were stepped up to look for rebels who might try to disrupt the country's elections. (Page A1, Column 1.) Iraq has used nerve gas in its war with Iran and is nearing completion of up to five extensive sites for the mass production of the lethal chemical warfare agent, according to United States intelligence officials. They said they had obtained what they believe to be incontrovertible evidence of the findings. (A1:2.)

Army officials said today that about 50 of the achievement medals went to personnel who got no closer to the fighting than the Pentagon. Other awards were given to staff and rear-area support troops at Fort Bragg, N.C., home of the 82d Airborne Division; at Fort Stewart, Ga., and Fort Lewis, Wash., bases for Army Rangers; and the headquarters of the Army's Forces Command in Atlanta. Asked for an explanation, the Army defended its awards system as a ''valuable and effective leadership tool to build unit morale and esprit.''

The Marathon Oil Company and Husky Oil Ltd. of Canada announced yesterday that they had reached a definitive agreement for Marathon to buy Husky's United States subsidiary, the Husky Oil Company, for $505 million in cash. Since Marathon Oil is a wholly owned subsidiary of the United States Steel Corporation, the step would further increase U.S. Steel's holdings in the oil business. S. R. Blair, chairman of the board of Husky Oil Ltd., said in an interview that the company was making the sale ''because we perceived on opportunity this year to convert our petroleum properties, which were not contributing much to our income, into cash.''

At least 60 people were killed and hundreds injured by a string of tornadoes that roared through the small towns and greening countryside of the Carolinas Wednesday night. The gigantic storm system swept on up the coast today, with gales that knocked out power to hundreds of thousands of homes and tides that scoured beaches and flooded seaside towns. The National Weather Service called it ''one of the most severe general cyclonic storms in recent history.'' The highest death toll was reported in North Carolina, where at least 44 bodies had been recovered by late today. The authorities said more than 420 people had been injured and 600 were homeless in a dozen eastern counties.

The East's biggest storm of the year battered the metropolitan area with snow, sleet, hail and hurricane-force winds yesterday, disrupting travel, commerce, education and the lives of hundreds of thousands of people. The storm caused widespread flooding, howling up the coast with winds up to 80 miles an hour and 20-foot waves that pounded sea walls like thunder. Beaches and shoreline property were heavily damaged and emergencies were declared in New York City, Atlantic City and New Jersey shore areas. Many Homes Without Power The storm knocked out power to more than 196,000 metropolitan-area homes, closed schools and businesses, forced the evacuation of thousands of residents along the shores of Brooklyn, New Jersey and Connecticut, turned highways treacherous and threw regional transportation into turmoil. ''In terms of property damage, lives lost and the area covered, this is the worst storm to strike the East this year,'' said Gene Salerno, a meteorologist with the National Weather Service in Rockefeller Center.

IN the 1960's days of Minimal austerity, when color, image and personality in painting were on starvation rations, emerging young artists were looking for something more robust. Slogging into the 70's, a generation fresh out of school seemed bent on remaking art again as a vehicle for individual passions. In its new exhibition, ''Five Painters in New York'' (through June 17), the Whitney Museum aims to show us how that generation - born between 1940 and 1945, with careers beginning in the late 60's and early 70's - came of esthetic age, via the work of five representatives: Brad Davis, Bill Jensen, Elizabeth Murray, Gary Stephan and John Torreano. Each is given what amounts to a mini-retrospective with a gallery to himself or herself, each showing roughly a dozen paintings from the early or mid-70's to the present. Each has a distinct approach; the five are related more by ''sensibility and circumstances'' than by ''obvious stylistic cohesion.'' we are informed by Richard Marshall, the Whitney's associate curator of exhibitions, who organized the show with Richard Armstrong of the museum's independent study program.

A Salvadoran Army commander said today that United States planes on reconnaissance missions were providing almost instant intelligence on guerrilla movements before and during combat operations. The commander, Lieut. Col. Domingo Monterrosa, whose area covers three eastern provinces where combat with insurgents has been heaviest in recent months, said in a telephone interview that he could not remember when the reconnaissance missions began. He said that in the last two and a half weeks their use had ''increased in a bigger way,'' in advance of the presidential elections last Sunday. Looking for Insurgents Colonel Monterrosa said the information from C-130 planes was generally relayed by radio to the high command in San Salvador, or could be sent directly to a United States adviser at the colonel's headquarters.

The index of leading economic indicators, which is the Government's main economic forecasting gauge, rose a healthy seven-tenths of 1 percent in February, prompting the White House to assert that the economy was ''still on a roll.'' The Commerce Department, which reported the gain, said February's rise was the 17th in the last 18 months. Last month's rise was less than the 1 percent January increase but well above December's advance of only two-tenths of 1 percent. The index was unchanged in November.

Friday JAPANESE-STYLE BECKETT Unlikely as it may seem, works by Samuel Beckett will be offered this weekend in the 14th-century style of kyogen - the humorous interludes that traditionally separate performances of Japanese noh plays. The performers are in the Noho Theater Group from Kyoto, Japan, a three- year-old ensemble. At the Asia Society, 725 Park Avenue at 70th Street, tonight and tomorrow at 8, it will present Beckett's ''Act Without Words I'' as well as ''A Pot of Broth'' by W. B. Yeats and two traditional kyogen works. At 7:30, Japanese and Western mime will be demonstrated and contrasted. (Tickets: $20; $10 for students. To charge: 288-6400, extension 286). Sunday at 2 and 7 P.M., Noho will perform three Beckett works and a traditional kyogen work at La Mama E.T.C., 74A East Fourth Street. ($8; reservations: 475-7710). TEXTILE WORKERS' PLIGHT

THE 1984 ''New Directors/ New Films'' series could just as well be titled ''All in the Family.'' From Hong Kong to Hungary, from Southern California to East Germany, family relationships seem to be obsessing film makers. At least two-thirds of the 18 feature- length films from 14 countries in the series this year focus on this topic. ''We didn't plan it - it just happened,'' said Joanne Koch, executive director of the Film Society of Lincoln Center. ''Sometimes common themes seem to surface spontaneously, everywhere at once.'' This is one of those years. This 13th annual showcase for fresh film talent from outside the United States or outside the commercial American mainstream is sponsored by the Film Society and the Museum of Modern Art's film department. The series begins tonight and runs for two weeks, through April 12, at the 57th Street Playhouse, 110 West 57th Street. Each movie will be shown twice. The stories depict young against old, technology against tradition, village versus city, suffocating materialism side by side with grinding poverty and, the world over, rebels who are often without a cause.

Carolyn Bass was standing at the front door and watching the boiling sky to the west when she saw the low black funnel, whipping back and forth below the clouds like the tail of a snake and moving straight toward her house trailer. ''And all of sudden the trailer started to shake, and the hail started to pound down like stones,'' she recalled today, sitting amid the debris that was once her home and her neighborhood. ''My mother and I grabbed my daughters and got out the door just as the whole trailer went right up into the sky.'' The four of them managed to pile into a car parked outside. Soon others, neighbors fleeing their own mobile homes, were there, too, pushing inside the doors and lying one atop another.

''And all of sudden the trailer started to shake, and the hail started to pound down like stones. My mother and I grabbed my daughters and got out the door just as the whole trailer went right up into the sky.'' - Carolyn Bass of Bennettsville, S.C. (A1:4.)