Autumn '82: Paris Milan London

Goodbye sportive, hello sophistication. There's a whole new mood in the autumn clothes shown all over Europe.

Enjoy your gingham and your prairie skirts while the summer sun shines, but brace yourself for looking good in very long, slim skirts and wide-at-top dolman jackets. The silhouette has been turned upside down.

Has anybody seen a lost winter coat? Practically nobody. The almost total disappearance of the coat was a talking point in the big shows of Milan, London, and Paris. What you get instead is a drifty piece of wool which you could call a cape, cloak, djellaba, poncho, stole-with-sleeves. Whatever this is, it is unlined, sometimes braid-edged (as at St. Laurent), and looks terrific slung across one shoulder like a matador.

It's not quite as dotty as it sounds, for you pile on three or four chunky basketstitch knits (a big item) underneath it. You can't do that with many tailored coats. The few coats there are tend to be, like Chloe's and Basile's, big herringbone classics worn two sizes too large.

You just can't keep a good idea down. Fashion editors everywhere have been telling women to abandon that look of the big wool shawl flung over one shoulder - it's been done, after all, to yawning point. So what do St. Laurent, Ungaro, and Jap show with scores of their new ensembles? That's right - even down to the thread of gold many consider passe.

Since jackets stole the news, what's so special about them now? Almost always they have dolman or raglan sleeves. Gone is the neat, tight armhole many found trim, others uncomfortable. Revers come all ways, but the prettiest are the soft , waterfall rippling ones many Italians showed. The jackets do button low, and often with just one button. Other times they swing free like the cape topping them. In red or emerald flannel over long slim black skirts at Chloe, these swingy jackets recall those of the 1940s called ''jigger'' jackets.

Blouses are just as pretty as last year's madly ruffled ones. Now they are slightly calmer, more Piero della Francesca than Little Lord Fauntleroy. Diagonal tucks ripple across the blouse front, while other styles feature all interest on one side, with a pleated rever, single. Designers like Giorgio Armani, who loves mixing three bold colors, used this whim for exciting silk blouses with each balloon sleeve a band of, say, purple, yellow, and red.

The low-waist dress is the one to look for. Often it's either elasticized on the hip or dramatically belted there. Milan in particular adopted the Renaissance look with chunky hip belts and necklets studded with old pewter coins.

These long-torso dresses are charmers in the mini length that's everywhere. In soft jersery they recall the sweatshirt fabric dresses of America's Norma Kamali. The influence of American designers grows apace in these big European shows, and many a knowledgeable fashion buff was heard to murmur, ''A steal from Ralph Lauren. . . . I seem to have seen that idea at Calvin Klein - or Kamali.''

The other mini that's hot news for autumn is the tiny narrow one, particularly in the leather that's sweeping all European fashion. This skinny mini is worn with a huge dolman sweater or a blouson jacket caught in firmly on hips. Many a coat or dress, especially at Chloe among the sweater dresses, has this cocoon shaping.

Colors for autumn are so sober you find yourself excited about navy blue with chocolate brown.

If you're thinking of just one gorgeous item for the autumn, consider something in leather. It's never been more chic and was used time and again in soft suede skirts (beautifully printed in flowers at Mario Valentino) or in silky-weight jerkins over Irish tweed jackets. And as for those all-important blousons, leather is of course tailor-made for them: Check with any cowboy.