Booking a European ski trip is a bigger gamble than it used to be. Warm winters and shrinking snowlines mean low-lying resorts can no longer be trusted months in advance, and with a warm, wet El Niño-pattern winter forecast, altitude is the single most important number to check before you book. An Alps-based expert who has spent six seasons helping Americans plan trips says the rule of thumb is simple: look for resorts topping out above 10,000 feet in France, Italy and Switzerland, and above 8,200 feet in Austria.

That rules out some famous names. Austria's Kitzbühel and Saalbach are wonderful towns with real ski history and megapass access (Kitzbühel is on Ikon, Saalbach gives Epic holders five days), but both sit low, and off-piste days are increasingly limited. France's huge Portes du Soleil domain, straddling the Swiss border with 360 miles of pistes, peaks at just 7,200 feet — these days rain above 6,500 feet is not unusual in the French Alps.

Even the two big American bucket-list resorts come with caveats. Chamonix is steeped in history — it hosted the first Winter Olympics in 1924 — but the Ikon Pass only includes the basic Le Pass, not Mont-Blanc Unlimited. That means no Vallée Blanche, no Courmayeur Skyway, and no top of the Grands Montets, arguably the three best things there. Budget an extra €90 (about $103) if you want the full experience. Zermatt delivers Matterhorn views and snowsure, high-altitude pistes, but at roughly double French prices, with food that lags France and Italy, and limited storm-day skiing.

The expert's top all-rounder? Tignes/Val d'Isère in France — glacier terrain to 11,339 feet, a genuine village at Val d'Isère, and one of the highest bases in the Alps at 5,906 feet. Day tickets run about $80, and it's on neither Epic nor Ikon, so you'll dodge the crowds of the roughly three million Americans on those passes. Epic fans get good value at Trois Vallées and Paradiski ($66-$85 per day).

Further south lie the under-the-radar picks. Serre Chevalier near Briançon is billed as the best big French resort most Americans have never heard of, with village charm at Monêtier-les-Bains and tickets around $78. Montgenèvre ($58-$66) links into Italy's Via Lattea, and tiny high-altitude Queyras resorts like Saint-Véran (9,186 feet) offer lift tickets from $48.

Italy is the value-and-culture play, with Aosta Valley now on Ikon: Monte Rosa for off-piste and touring (base yourself in Alagna or Gressoney), and Cervinia as a cheaper, better-eating alternative to Zermatt on the same Matterhorn ski area — a new 3S cable car due by 2030 will make the Italian side faster to the Klein Matterhorn than Zermatt itself. Via Lattea offers world-class tree skiing around Sestrière.

The broad trade-off: France and Italy win on food and price but can be disorganised; Switzerland and Austria run more efficiently, get more snow, and boast the Alps' best lifts — most of its 3S cable cars. For a snow-safe trip this season, prioritise altitude over fame.