It's late as you come off the lift - time for only a couple more runs. It's icing up, and you wonder where to the snow's still good. Maybe back where you started early in the morning, before the crowds came; on Lafayette's Leap, or Margie's Delight, Ball Hooter, High Hopes or any other advanced or intermediate trail in the region.

A few quick turns, shoot down the catwalk - looking good - a quick edgeset to control your speed, over the lip and - eeek! The whole slope has a bad case of the washboard bumps. This is mid-Atlantic skiing in its commonest and most challenging fit of pique. But don't despair - here's all you need to know to ski the bumps.

First some background. Bumps, or moguls, are simply large mounds of snow that pile up because of modern short skis and short-radius turns. They build during the day on relatively advanced slopes, where skiers bank turns off the sides of existing moguls and thus force more snow up on top. Skiers also carve out the depressions between moguls. The net effect is a stormy sea of close-packed humps sometimes three or four feet high, eight to ten feet wide, and usually icy on the lower part of the downhill side where most skiers carve turns to avoid first one mogul and then the next.

The bumps are difficult, no doubt about it. But many skiers make them worse than need be by resisting the ways they catapult our bodies rather than using the bounce. A mogul creates two forces as you ski over it: more pressure on your skis as you go up the uphill side, and unweighted skis as you go over the crest and down the downhill side.

You can use these forces to ski moguls well. The most useful technique for skiing here, where it's often icy, is to set your edges just before you come to the crest of a mogul. This is called an "edgeset" or a "check." You'll stillbe goin up the uphill side, so there'll be a lot of pressure on your skis and your edges will bite firmly when you set them. The edgeset, done with a downhill ski, will also check your speed a bit.

Your knees should absorb the shock of the edgest, which is immediately followed by a pole plant on the side you want to turn toward. The recoil from the edgeset helps unweight your skis. As your feet over the mogul's crest and you're completely unweighted, shift your weight to wint will be your downhill ski as you carve the turn.

Think of it this way: You're skiing with your weight on one ski at a time - carve a turn on your downhill ski and end with an edgeset on the ski. Before you are unweighted to make the shift to the other ski, that will carve the next turn and end with the next edgeset.

THe reason the technique is so useful is that it checks your speed. You're unweighted only on instant for the weight shift, which occurs as your feet pass over the crest of the mogul. This lets you force your skis back onto the snow at the very top of the downhill side of the mogul - which follows naturally from the knee - flexing that absorbed the shock on the uphill side of the mogul.

The whole sequence lets you get ready for your turn, make an edgeset, unweight, shift and carve your turn before you hit the ice on the lower part of the mogul's downhill side. It takes precise skiing and timing, and happens in about a second.