It may have been bitingly wintry outside Lisner Auditorium last night, but everything was in vernal bloom inside as the Washington Ballet launched its "Spring Series" for 1979 with one of its most stirringly impressive programs to date.

The evening's fare was the kind of scintillating mixture that has lent added excitement to the growth and enrichment the company has been experiencing over the past three years -- the premiere of a new work by young Eric Hampton, a new company member formerly with the Netherlands Dance Theater; George Balanchine's perenially welcome "Serenade"; and, forming the backbone of the program as well they should, two of the ballets by resident choreographer Choo San Goh which have been a major factor in the troupe's remarkable advance.

Hampton's "Slow Movement" is set to an early (1905) piece for string quartet by Anton Webern in a broadly melodic, harmonically tonal idiom falling somewhere between Brahms and Mahler. It's a perfect canvas for Hampton's soulfully poetic pas de deux, which has the couple moving in and out of still poses and yearning stretches to pensive walks in parallel and eventually to impassioned spins, lifts and dips. The two also circle one another, echoing the nocturnal evocations of the backdrop's rising moon.

The delicacy of mood and gesture often suggest Antony Tudor, but Hampton's well-knit designs have an identity of their own. The piece made a fine vehicle for a display of lyrical legato by Lynn Cote and John Goding; all in all, it's a splendid addition to the repertoire, in a vein nicely contrasted to the sinewy vigor of Goh's work.

The Goh ballets, both of which received sterling performances, were "Introducing...," a briskly witty and resourceful charade to the clipped rhythms of Stravinsky; and "Fives," the complex yet wonderfully lucid and bracing abstraction to Ernest Bloch's "Concerto Grosso" which is Goh's strongest and most distinctively personal opus thus far.

Technically, the performance of "Serenade" -- by a cast of 26 necessarily bolstered by some advanced students -- had its shaky aspects; admirably, though, the line and spirit of the choreography were held in firm focus.