´óÏó´«Ã½

With the opening ceremony of the Paralympic Winter Games this week, and Beijing's average temperature in March well above freezing, what weather conditions might the athletes expect?

Some of the events will take place indoors. The National Aquatics Centre, used in the Beijing 2008 summer Paralympic Games, has been converted into the "Ice Cube" in preparation for the wheelchair curling competition. Ice hockey will take place in Beijing's National Indoor Stadium.

But what of the outdoor events and where will they take place?

Roughly 75km north-west of the city centre, the Xiaohaituo mountain area in north-west Yanqing will be the setting for the alpine skiing events, including the downhill and Super-G.

The Zhangjiakou zone, approximately another 100km further on, will host the biathlon, plus cross-country skiing and snowboarding.

Whilst the mountain settings of these alpine events boast spectacular scenery and breathtaking runs they lack just one vital ingredient: real snow.

Beijing is a city where snow and precipitation are usually hard to come by in the colder months. The winter tends to be dominated by a semi-permanent area of high pressure that feeds in cold air from Siberia, and this only slowly relinquishes its grip in early spring.

The city typically records a maximum temperature of 12C in March and an average minimum temperature of 1C.

Zhangjiakou is a few degrees colder and gets more snow each year than Beijing since it is at a higher elevation. The average annual snowfall in the area is reportedly 63cm. Compare this with Val d'Isere in the French Alps, admittedly at a higher elevation, where annual snowfall amounts are 450cm.

The Winter Paralympics share a venue with the Winter Olympic games - and International Olympic Committee (IOC) officials warned in their evaluation of the Beijing bid in June 2015 that the venues "have minimal annual snowfall and for the Games would rely completely on artificial snow".

The climate of the area means organisers have to make their own snow, just as they did in the Winter Olympics.

It was estimated Beijing 2022 would need about 49 million gallons (222 million litres) of water to create the required artificial snow. A recent report by the Sport Ecology Group at Loughborough University and Save Our Winters outlined the environmental dangers of artificial snow.

It's not the first time the IOC has chosen an alpine venue with more rock than snow.

Pyeongchang, the South Korea venue for the 2018 Winter Olympics and Winter Paralympics, has a similarly cold, arid climate and also required vast quantities of artificial snow. The balmy weather for the 2014 Games in Sochi, Russia, left many athletes grumbling about slushy conditions. And even Vancouver in 2010 had to drive truck loads of snow into the melting Cypress Mountains venue.

While the focus has been on the lack of snow, other weather elements can cause problems for winter sports, including fog and high winds.

Organisers will hope for timely and accurate forecasts to help schedule and run the events safely. The Beijing Institute of Urban Meteorology is leading forecasting at Beijing 2022.

They will make use of sophisticated Doppler radar and more automated observation sites, with the aim of producing a high resolution forecast model showing detail down to 500m for the greater Beijing-Tianjin-Hebei (BTH) region and 100m in two small domains covering the key event areas.

In addition, the snow making and snow storage processes need accurate high-resolution short-term forecasting of low-level and surface temperature, humidity and wind.

Climate change means the winter sports season is getting shorter and ski resorts are increasingly relying on artificial snow, so expect more talk about winter weather in the coming years.