By noon the snow was several inches deep at Washington's Oyster Elementary School, and with the stern concentration of a quartermaster general, 11-year-old Dunia Amaya-Alvarado was patting together the first snowballs of her life."

"Dos, tres bolas," Dunia muttered, stacking them into a new pyramid. Two and then three snowballs. This was serious business. Dunia, whose family recently arrived here from Honduras, had been designated chief snowball manufacturer for the sixth-grade girls. The boys, crouching together at the other end of the play-round, were amassing ammunition of their own.

Erasmo Garza, the sixth-grade teacher, stepped boldly into the open playground. "Ataquen!" he cried - attack - and one fat snowball hurtled out over the field. Then to a chorus of war whoops, the snowballs began flying in earnest: snow in the hair, on the face, down the collar, up the sleeves.Dunia stacked bolas feverishly, pausing only long enough to observe, with some surprise, that extended kneeling in the snow makes for wet knees.

The snow was claiming a good deal of attention inside Oyster, too. The school is at 29th and Calvert streets NW, attracting a large number of Spanish-speaking children, and for some of the more recent local residents wolfing down sandwiches in the auditorium yesterday, the heavy snowfall was a whole new experience.

"Para jugar snowman," said 9-year-old Ricardo Jimenez, delightedly - to play snowman, sculpting what he described as a three-foot tall fellow with button eyes and a mouth made of corn. Smiling, Ricardo is from Guatemala and said he had never built such a creation before.

Scott Ratana, 8 years old and from Thailand, said he had welcomed his first real snowstorm. Another boy had played "snow blurries," but on his back, sliding declined to define them.

Winston Cox, 8 and from Jamaica, said he had seen snow before, but never so much of it. "We were playing 'Bigfoot,'" Winston said, explaining that this requires the discovery of big empty tracks in the snow. Then you stalk the tracker, Winston said. What if you find him? "You throw snowballs," he said, with a touch of contempt for a dumb question.