At about 6.45am, I realise that I'm not going to be going skiing today. We're at a rave in an underground car park, DJ and stacks of pounding speakers at one end, a makeshift bar on trestle tables at the other. The tightly packed crowd sports sunglasses, skinny jeans and spiky haircuts. We could be in Hoxton or Hackney but, in fact, when we finally climb up the stairs into the frail morning light, it's into the main street of a charming, traditional Austrian village, Mayrhofen.
It's April, the end of the ski season, and the final night of Snowbombing – the climax of the winter's party calendar, the ultimate end-of-term blow-out, and an event that in the 10 years since its inception has grown to be recognised as the Olympics of après-ski.
To be honest, it's not really après-ski at all. This is a full-on music festival that just happens to be taking place in the mountains. Forget lederhosen-slapping oompah bands and cheesy Euro-pop, the line-up for Snowbombing 2009 includes Fatboy Slim and Grandmaster Flash, Dizzee Rascal, The Whip and Zane Lowe.
Gareth Cooper, a tour operator from Manchester, dreamt up the idea after becoming bored with the terrible music usually played in ski resort nightclubs. 'We thought, well, if the mountain won't come to the music, the music will come to the mountains,' he says. So in the spring of 2000, a group of 200 people, including a few DJs and their record bags, set off for the first Snowbombing, in the tiny French resort of Risoul. It was chaotic and disorganised but raucous and unique, and since then the event has grown and grown. Next year's 10th anniversary event will boast seven venues, 30 live acts, 70 DJs and 5,000 'Snowbombers'.
And it's no longer alone – inspired by Snowbombing's success, music festivals are springing up across the Alps. This winter sees the first Snowside, partly organised by the team behind the Secret Garden Party, while comedy-themed Altitude, and electro-focused Tignesfest will have their second outings. Most take place in the final weeks of the season, when demand, and prices, drop, and hoteliers welcome even the rowdiest guests with open arms.
After moving around for a few years, Cooper brought Snowbombing to Mayrhofen in 2005 and realised he had found the perfect location. For a start, the resort embraces après-ski with a passion all winter long, so the locals were unlikely to be easily shocked. And, crucially for such a late event, should there be little snow, it's just a 20-minute, free bus ride up the valley to Hintertux, a glacier ski area with the country's highest lift and guaranteed skiing all summer long – not that skiing is really that high on the agenda for many Snowbombers.
As I wander back to the hotel, the previous day's action on the slopes is a distant memory. Mayrhofen sits among fields at 630m in the flat-floored Ziller Valley, with mountains rising almost vertically on either side. We'd skied all morning, relishing the metre of fresh snow that had fallen earlier in the week, then spent the afternoon on the sunny terrace of the Grillhofalm, watching professional snowboarders from across Europe compete in the Highway to Hell competition.
Back in town, the fancy dress street party was well under way by mid-afternoon. Snowbombers love nothing more than fancy dress, and the streets thronged with Snow Whites and dwarfs, every kind of lion, bear, badger and chipmunk, an excellent Adam Ant and a disturbingly well executed Osama bin Laden.
Some of the venues are as unconventional as the audience. Earlier in the week we'd seen Madness play in a forest clearing. Tonight, we took the Ahorn cable car, opened late for the event, back up the mountain, and followed a trail of flaming torches to the Arctic Disco, an igloo big enough to hold 200 people, where Krafty Kuts was spinning discs in a DJ booth carved from the ice. We danced until it grew so hot the walls were melting, then we danced some more outside under the starry sky. Eventually, we skidded and slipped back across the piste to catch the lift down to the town, and a hundred people started doing the conga around the cable car.
It was 11pm, but the party marathon had barely begun. At Snowbombing there are only five hours in each 24 when there isn't some music event going on. We trawled from club to club, to watch the Filthy Dukes, DJ Yoda, and Erol Alkan, before finally ending up at the underground Garage for Tristan da Cunha.
By the time I finally reach my hotel, the waiters are clearing away breakfast. It occurs to me that though the sound and light systems have grown slick and professional, Snowbombing's atmosphere has changed little since that original trip to Risoul. It still feels less like a commercial venture, more like a group of friends coming together to have the time of their lives. Maybe I'm getting a bit tired and emotional, but it has been a very long night.
■ Snowbombing 2009 (www.snowbombing.com) runs from 29 March to 4 April in Mayrhofen. Week-long packages cost from £249 including six nights' accommodation and access to most events, but not flights. Transfers from Innsbruck, Salzburg and Munich airports, cost from £15 each way.
This is an edited extract from Tom Robbins' book 'White Weekends'. To order a copy for £18 with free UK p&p, call 0870 836 0885 or go to observer.co.uk/bookshop
