THE OMINOUS clouds thunder and the lightning strikes, illuminating the cedar trees to thei very roots. Stream of rain fall, givng life yet threatening floods. The sacred Buddhist wheel spins on.

All this drama - and more, if you could but read it - are woven into a blue, green and red/brown silk Japanes robe of the late 17th century used in the rich ritual drama of Japan called No that has been performed for more than 500 years.

Tenka ichi - "First under Heaven," - was a title a Japanese shogun (ruler) gave to an artist or craftsman of exceptional genius. In many ways, the National Gallery of Art's exhibit of No robes and masks (April 10 - May 22) qualifies for this accolade. The 145 objects in the exhibit, mostly from the 17th and 18th centuries, are part of the collection of the Tokugawa family of Nagoya, Japan, powerful shoguns from 1603 to 1868.

This show marks the first time any part of this remarkable collection has been seen in the United States. The selection is just a sampler of the 600 garments, 156 masks and thousands of other treasures from the Tokugawa Art Museum of Nagoya. Even in Japan, the objects are seldom seen, usually kept packed away in great vaults. Because of their great rarity and fragility, each of the objects will only be on view for two weeks, during the six-week run.

Invitation openings to the National Gallery exhibit begin Thursday with the opening to the public next Sunday. Just as you don't need to have seen a pyramid or bathed in the Nile to appreciate the treasures of King Tut, you don't need to know No drama to appreciate the robes and masks. While evoking ghosts of their past they stand by themselves as objects of wearable art. The show comes to the United States at a good time, because of the new interest in exotic, romantic art - and because of the great number of Americans who are learning to create their own textile arts: quilting, needlepoint and embroidery.

The 250 classic plays of No are divided into five subjects according to leading roles: plays about gods, about military heros, women, demons and a catch-all group that seems to be mostly about mad women. The drama still flourishes in 15 or so theatrical companies. Today more Japanese than ever see and follow the great No dramas, whereas in times past the pleasure was reserved for the nobility.

In a No play the actors mime, chant and dance to flute music that has heavy accents of drums and seems not to be of this world. The stage is almost bare except for a painting of a pine tree. The brillant robes, as mirrored in the highly polished cypress stage, provide both color and action.

Rand Castile, director of the Japan House Gallery in New York, has been working to arrange the National Gallery show for seven years. "The Tokugawa family has the greatest of all Japanese art collections," he said during installation of the show. "It has been said that the Medici would be the only European counterpart as patrons of the arts. We wanted to bring the No costumes to this country because of all the Japanese arts they are the least known. Even in Japan they are not exhibited. And the No costumes are the most important record of what the early No drama was really like. It is a rare pleasure."

There are infinite variations of No robes. The background patterns are most often geometric, angular, formal, mysterious, hard edged. The surface pattern is pictorial, most often flowers but sometimes bamboo, fans, fences and lions.Okochi Sadao, the Tokugawa curator who accompanied the robes here and helped Tokugawa Yoshiunobu write the lavish Japan Society catalog, says the costumes are descended from Japanese court dress, influenced by the Chinese Tany dynasty.

The No actor interprets his character first by choosing a mask and meditating upon it and then by the selection of the costume. As Okochi writes in the lavish catalog of the show, "The costume is the visible flower which brings form to the flowering (hana) of the actor's talent."

The brillant reds worn to depict a young and beautiful woman are of the type of robe called karaori , a brocade or satin-weave silk using threads of five colors and intricate workmanship. The material is very stiff so the actor must move with great pomp and majesty.

The atsuita karaori robes have stronger surface patterns befitting the dignity of the male roles, but are sometimes used for an older woman depicted as a ruling character.

Nuihaku robes are embroidered in a raised, three-dimensional effect and appliqued with gold or silver foil. These are usually women's costumes.

Surihaku robes use gold or silver foil applied over a stenciled adhesive. The grid pattern, according to Okochi, is thought to resemble fish scales. The costume is a favorite for demon-tormented women.

Noshime are woven of raw silk with a weft of glossed silk. THe striped variety is usually worn in the plays as inner robes.

In some of the plays, the robes may be worn draped around the shoulders or folded around the hips. One robe even has embroidery on the top and not on the bottom, because only the top was expected to be seen.

The variations are infinite: the "no color" robes for the mysterious woman of great age; the magnificent robes decorated with pure gold thread for the role of prince; robes whose flower decorations set the act in spring or winter and give the location, behind a bamboo fence or a latticework. There are many traditional combinations, such as the rabbit and the peony.

Some of the robes have brocaded backgrounds, with the design an integral part of the weave. Others are embroidered in varying techniques, including the gold work called couching, where pure gold is twisted into thread and then mounted with silk thread. The subtlety of the process is hard to believe without seeing it. Some of the sheer gauzes make moire patterns as the actor moves.

Okochi pointed out on a Nuihaku robe an embroidered mythical bird. The bird is said to herald a golden age by appearing in the paulownia tree when a great and good emperor comes to the throne. Okochi, in a complement typical of the polite Japanese, said the bird had come to America to honor Carter's presidency.

Despite the fact that the robes have been used in performances over a great number of theatrical season, most of the colors remain remarkably vivid, unlike European textiles of a similar age, Castile said. The condition of the fabric is also amazingly good. The weaving techniques are extraordinary - two people, working a full day, could weave only five centimeters of one design.

As Okochi explained, meanwhile checking the condition of the robes after their trip here, the actors in the summer try to sweat a great deal before putting on the robes so they will remain dry during the performance. The robes are never drycleaned and always folded in the same way, Castile said.

The designs on the No masks also have their own meanings. The masks have subtle stripes around the hairline to signify age; gold rims around the eyes to mark the wearer as not of this earth; eyebrows, placed impossibly high on the brow, to signify a lady of great wealth. Move the mask five degrees up and the character is happy; move it down and the rigid mask changes, through the change of shadows, to tragedy.

The masks are made of cypress carved to a thin shell. The lips are painted with red clay, the outlines with ink. Some of the teeth are embellished with gold. Color is used to evoke shadows and make the mask seem more three-dimensional. The actors see dimly through nostrils or sometimes the mouth.

The ritual unwrapping of the No robes on their arrival was impressive. Only the Tokugawa curators were allowed to handle the precious objects.

The method of wrapping and unwrapping is centuries old. The two curators, Okochi and Atobe Yoshiko, worked at each end, unwrapping as though performing a dance, in perfect harmony to some unheard drum. First came the muslin sheeting on which the identification was painted in bold, handsome strokes; then the brown paper to keep out the light, folded just so; and last the tissue paper, white to protect the color with a texture to keep the robes from wrinkling.

But to Okochi Sadao, wo apprenticed 10 years before becoming curator to the No robes, no care is enough.

As he unwrapped still another national treasure, Okochi, struggling to make himself understood across languages, oceans, time and culture, said, "We hope that Americans will not only appreciate the beauty of our costumes but through them will understand our minds and our innermost thought. The subtlety of the art is the deepest pool of knowledge of the Japanese philosophy." The exhibit was financed by grants from the Coca-Cola Co. and independent bottlers of Coca-Cola in Japan. From Washington, the show goes to the Japan House Gallery in New York (June 1 - July 17) and the Kimbell Art Museum in Ft. Worth (July 27-Sept. 4.)