If the warm winter has wrecked plans for the perfect ski weekend and your ski equipment is just gathering dust, it may be time to bring your skiing indoors.

Tucked away in a quiet corner of Silver Spring is the Aspen Hill Ski Training Center. While it lacks the cozy ambiance of a ski lodge, it does offer the benefits and challenges of outdoor skiing while eliminating the unpredictable weather variables and interminable waits for the lift.

The center's indoor ski deck, which can be adapted to any level of skiing expertise, is one of 36 such facilities in the United States. The school's certified instructors provide closely supervised sessions and an opportunity to learn or improve skiing techniques. They claim 30 minutes on the deck equals a day of skiing on any of the local slopes.

"The idea here is not to keep people off the snow," said ski school director Kim Swezey, a veteran racer and instructor. "We're here to make their skiing experience more positive. If I could design a life, I would teach on the deck and ski on the snow. I'd have the deck right on the slopes."

The only thing missing from the indoor deck is the cold and the momentum of going downhill. The deck is like a treadmill, although the surface area is much larger. The deck, which operates by remote control, has variable speeds and, since the slope is adjustable, both nordic and alpine skiing are possible.

The surface is thick carpeting which, unlike snow, won't tolerate technical errors. That, said Swezey, is the beauty of the device. "You have to execute the techniques properly on this surface," says Swezey, "and once you learn to do things right you can make the best use of your equipment. You can learn how to ski efficiently."

The center provides boots and skis finished with a special Nylatron base that allows better maneuverability on the carpet. The skis are quite short compared to the ones used on snow.

"On the deck," said Swezey, "I can watch hundreds of turns. I can't do that when I'm watching someone come down a hill. This way I can evaluate a person's skill more effectively and fix any problems."

The deck is valuable for both beginners and advanced skiers.

"When you ski on snow there are a lot of distractions," says Swezey. "This is a controlled environment with low variables and no distractions. The only thing left is learning."

The session begins at the bottom of the hill, with the skier holding onto a safety bar that stretches the width of the deck. With the instructor at your side, you feel the surface of the deck begin to move under your feet. After a few trips guiding yourself back and forth across the deck on the bar, it's time to let go.

It takes a few minutes to get used to the pull of the carpet, but once learning to maneuver the skis, you can safely become suspended in the middle of the deck, floating effortlessly from side to side. The attention and encouragement of the instructor is constant, which would be logistically impossible on a ski slope.

Swezey stayed inches away during the $20, half-hour session, talking through every move. The lesson seemed to provide more technical knowledge than a few years of practicing on snow.

Aspen Hill Ski Training Center hours are 8 a.m.-10 p.m. Monday through Friday, 10-5 Saturday and Sunday. Call (301) 598-5200.