THERE ARE the snows of yesteryear -- at the Corcoran Gallery, in "The Pennsylvania School of Landscape Painting: An Original American Impressionism."

The show highlights 11 painters associated with an artists' colony that centered on New Hope, north of Philadelphia on the Delaware River. Deep in snowy landscapes, most of the 80 scenes they painted in the early part of this century could have been any small town in the Delaware Valley.

Some of the artists worked in near-blizzard conditions. To fight the wind, Edward Redfield anchored his easel to a tree. Walter Schofield painted in two suits, a coat and lumberjack's boots.

They achieved a realism touched with impressionism: Painting en plein air was something that had to be done, said Redfield, to capture a scene on a particular day. Both of them caught that flat light during a snowfall.

By contrast, William Lathrop -- who founded the New Hope Art Colony with Redfield -- painted from memory, and his landscapes are subtler, more atmospheric -- and free of snow.

On warmer days, for Daniel Garber, whose idyllic interpretations echo Frederick Church, the inspiration was a quarry in evening, with the autumn sunset playing its colors on a scarred rock wall; or a bright orange dirt road cutting through the rolling checkerboard of fields; or "Springtime: Tohickon," with the river shimmering pink and blue and trees bursting in pastels.

Tenements, shops and mills and their workers empassioned Robert Spencer, who studied painting with Garber. In these paintings, one makes more assumptions about working and living conditions from the buildings than from their occupants, uniformly anonymous.

Perhaps it's the preponderance of snow in most of the other pictures that makes Redfield's "The Burning of Center Bridge" (1923) stand out. It was an exciting local event, watching the 112-year-old bridge across the Delaware burn down after it was struck by lightning.

For us, the fire and smoke relieve the monotony of grey skies massed with the bare stick-branches of trees. For, although no two snowflakes are alike, unfortunately the same cannot be said for snowscapes. THE PENNSYLVANIA SCHOOL OF LANDSCAPE PAINTING: AN ORIGINAL AMERICAN IMPRESSIONISM -- At the Corcoran Gallery of Art, through January 20, 1985.