As the hours pass and the wine begins to flow, the talk turns to snow, a skier's only essential element. We can manage without the usual resort conveniences: on-mountain restaurants, trail maps, maybe even the chairlifts. But without snow, preferably fresh powder, we'd be nowhere.

George, our waiter tonight and a ski bum by day, cocks an ear. There's no such thing as bad snow, he tells our table. If it's on the slopes, he's there, skiing everything from packed powder and crusty glades to windy cornices and icy snow bowls.

"Never had a bad day in 25 years, and I've skied just about every place you can name," he says, clearing the plates at the Lynn Britt Cabin, on the slopes at Snowmass Resort in central Colorado. He brushes away the crumbs with a flourish. "I guess I'm just lucky."

Now, if George has been cruising America's ski trails for that many winters and at that many ski resorts, he's probably developed an intuitive sense of snow. When you work at a ski mountain, patrolling the snow by day or grooming the slopes by moonlight, reading the signs becomes second nature.

But the average recreational skier has to pick a date and takes his or her chances. If you have just a few days to ski -- a week or a couple of weekends -- why not pick the resort most likely to have first-rate snow?

Snow conditions depend on a variety of factors: the latitude; elevation; sun exposure; and micro-climate features such as lakes, parallel ranges and deserts. As spring approaches, nighttime temperatures and storm patterns come into play. Get to know the skinny, then plan ahead so the snow is there when you are. Or choose one of these six resorts known for predictably fine snow.

SNOWMASS RESORT, CENTRAL COLORADO

For fresh powder and deep coverage from February through March, we like Snowmass Ski Resort, 20 minutes from the town of Aspen. From December on, a combination of early-season snowmaking and scattered snowstorms keeps Snowmass' 11,000- to 12,000-foot mountains mostly white and skiable. But Snowmass' heaviest snows fall in late February and March, accumulating an average of 300 inches of snow on the trails, a thick base that lasts until the resort closes, usually in mid-April. Freezing temperatures at night and the region's famously low humidity tend to preserve powder conditions, especially at higher elevations. Good grooming keeps slopes smooth until the end of March when sunny afternoons finally turn the lower ones to slush.

We try to make reservations for the first week of March, the best month statistically for total snowfall. With thousands of slope-side condominiums in Snowmass Village, lodging is rarely a problem. See more at www.aspensnowmass.com.

BIG SKY RESORT, SOUTH-CENTRAL MONTANA

Out back and beyond is how most skiers feel on their first day at Big Sky Resort, on the wide open snowy slopes of 11,176-foot Lone Peak. Where are the crowds, the lift lines, the trampled-to-mush trails? It may take you a little longer to fly into Bozeman and drive an hour to Big Sky, but the pleasure of skiing unspoiled wilderness, as it was when skiing was in its infancy, will make all other ski areas look shoddy.

Since early winter snows aren't guaranteed, even here in the nation's higher latitudes, wait until December to pick your ski date. After that, the location of the mountains and winter's predictably howling blizzards tend to create first-rate ski conditions from January on, with regular top-ups lasting through April.

Log onto the website, but don't be fooled by the array of scenic photos and hot doggers negotiating vertical couloirs. Big Sky's terrain is planned for skiers of all levels, including kids and beginners.

In 2003, when Moonlight Basin Ski Resort opened on Lone Peak's other (north) side, the skiable terrain doubled to 5,512 acres, especially after Moonlight installed the now-famous Tram to the top, opening official access to killer terrain in the legendary Headwaters Bowl. See more at www. bigskyresort.com.

WHISTLER-BLACKCOMB, BRITISH COLUMBIA

This mammoth pair of Canadian resorts, with 8,171 acres between them on two adjacent mountains north of Vancouver, is farther north than any continental U.S. ski area. Whistler's first snows typically fall in November, and by December you can ski most slopes. Total annual snowfall here usually reaches an impressive 33 feet.

But the low elevation (between 2,000 and 7,400 feet) and the coastal range location can be a problem. Together they can bring rain to the base village and pea-soup fog to mid-level slopes. Visibility shrinks to zero, a disconcerting experience. But you can finesse the problem by boarding the gondola or nearest chairlift and riding up through the mist to clear skies.

Snow falls throughout the winter and into May, making for great ski conditions especially on the top terrain. Unless it's windy, conditions are generally better up high, with some north-facing slopes skiable into June or later. Most Whistler fans recommend February and March for the best snow coverage and clearest visibility. You take your pick of dates. Accommodations are ample, ranging from budget rooms to luxury lodges. See more at www.whistlerblackcomb.com.

HEAVENLY RESORT, Lake Tahoe, Calif.

With a reputation for some of the West's most unpredictable winters, when the snow finally does come to Heavenly Resort, at the south end of Lake Tahoe, it comes in a big way. In a good year, the white stuff piles up in huge drifts, sticking to the ground and sidewalks and blocking chairlift platforms. By January, most of the mountain trails -- which straddle the California-Nevada border -- will be open. In record-breaking years, the heaviest snowfalls arrive in February or later.

Heavenly's 10,000-foot top elevation means that trees grow to the summit, helping to shade and slow down late-season melting. But Lake Tahoe can create a "lake effect," making late-season snow wet and sticky, the reason for the nickname "Sierra cement." Colorado skiers poke fun at the "cement," but Californians and Nevadans who treasure their lake ski it with aplomb. If the winter looks like a blockbuster, you'll know by January, in time to find rooms for a ski trip during the non-holiday weeks from early February to early March. For more, see www.skiheavenly.com.

TAOS SKI VALLEY, NORTHERN NEW MEXICO

When the snow's good at Taos Ski Valley, a three-hour scenic drive north of Albuquerque, it's very, very good, as light and feathery as talcum powder. When it's marginal -- in the occasional New Mexico drought years -- you may have to search for it. If you ride to the top of the highest lift, at elevation 11,819 feet, then climb 40 minutes more to the top of Kachina Peak, at 12,481 feet, you'll find it. For some skiers, that's too much effort.

Happily, the high elevation, thin air and arid desert climate at the tail end of the Rockies make for super powder snow, especially in March when most of the longest and strongest storms settle over the range. In an average year, the snowfall measures about 305 inches, keeping most of Taos' rugged, north-facing slopes white.

Despite the mountain's reputation for heart-stopping expert steeps, Taos has bunny slopes at the base and delicious intermediate runs at mid-mountain. Hotel rooms in this tiny and most charismatic of America's ski villages are limited, so book space as soon as winter weather forecasts look promising. For more, visit www.skitaos.org.

STEAMBOAT RESORT, NORTHERN COLORADO

For whisper-light snow, with multiple feet on the ground by January and storms through March, point your skis toward Steamboat. The micro-climate in the northern Rockies, on Interstate 40 west of the Continental Divide, produces two storm patterns that blow through at predictable intervals, ensuring regular dumps of Steamboat's legendary (and copyrighted) "champagne powder."

The resulting ski conditions more than compensate for the resort's lower elevations (6,900-10,500 feet) and its south-facing slopes, about 23 percent of the total. You won't find above-timberline bowls at this altitude, but a mix of open slopes and trees to the summit create big views and challenging glade skiing.

Far west of the more popular ski areas closer to Denver (those along Colorado's I-70 corridor), Steamboat's uncrowded slopes, busy ski school and an active family orientation make this a popular destination resort. Children's programs, the ever-generous Kids Ski Free packages and a wide choice of base area condominiums in all price ranges make Steamboat a top choice. See more at www.steamboat.com.

SNOWBIRD SKI RESORT, UTAH

Of Utah's many Wasatch Mountains ski areas, Snowbird stands out for an unusual combination of features that create what Snowbird fans claim is the West's best powder snow.

A high elevation, between 8,000 and 11,000 feet, plus very dry air from the arid Great Basin location and endless "lake effect" moisture from the Great Salt Lake, in the valley just to the west, combine to produce monster winter storms. So much snow falls -- an annual average of 500 inches -- that Snowbird regularly opens in mid-November and stays open until Memorial Day.

Though skiers like to hype Snowbird's vertical powder steeps and glades, recreational skiers shouldn't be wary. Only 35 percent of Snowbird's 2,500 skiable acres are rated for experts. The rest is divided between beautiful beginner and intermediate runs. If you need more elbow room, ski over to sister resort Alta Ski Area (www.alta.com), which shares lift ticket privileges and ski slopes with its neighbor.

Privately owned, Snowbird has kept its small-town charm, evident in the local accommodations, with rooms in four lodges operated by the Little Cottonwood Canyon Resort. Restaurants and ski rentals are also on site. The resort is about 14 miles from downtown Salt Lake. See more at www.snowbird.com.

Anne Z. Cooke is a travel writer based in Venice, Calif.