What will the snow be like this year? This is the question on everyone’s lips in Tirol as winter approaches. Finding an answer is often complicated. We set out in search of clues –indoors and outdoors.
PHOTOS: DAVID SCHREYER
What will the snow be like this year? To answer this eternal question, Lukas Ruetz must know what this strange machine on the mountain knows. His weather station, a collection of rods, funnels and cables, is easy to reach by Tirolean standards. From the Kühtaisattel ridge it is only a few metres up through the thin forest. Nevertheless, the trail is difficult –Ruetz often sinks up to his knees in the seemingly solid snow. “Faulschnee,” he says, a word used by experts like him to describe soft, brittle snow such as this. It has rained in the night and in the morning; now the sun is beating down from the clear blue sky. The snow is wet, heavy, unpleasant – a world away from “Wildschnee”, the light and fluffy powder that all skiers dream of. “Growing up as a child, the weather forecast was always wrong,” says Ruetz. “Today I know for myself how difficult it is to get it right!” What will the snow be like this year? This is the question on everyone’s lips in Tirol as winter approaches. Anyone who lives in the middle of the mountains has a special relationship with the white stuff which first sugars the peaks and then wraps them in white for months. Snow forms the basis for the Austrian national sport of skiing as well as the key industry of winter tourism. As such, weather has a big impact on the economy. At the same time, heavy snowfall can also become dangerous. Trees break, snow and ice make the roads and railways unpassable, people and whole valleys are cut off from the outside world. Avalanches thunder down the mountain. Snow, therefore, is a question of life and death. And yet, predicting its arrival and behaviour is very complex – and constantly changing.
Lukas Ruetz, 27, is one of those trying to find answers to the snow question. Alongside his main job working at the Gasthof Ruetz in St. Sigmund im Sellrain, a hotel owned and run by his family, Lukas draws on his degree in geography to give lectures on avalanche awareness and provides the regional avalanche warning service with information on the current snow conditions. In his blog he reports about the weather conditions in the Sellrain Valley. He has been fascinated by the subject since his youth, explains Ruetz, as he trudges ahead through the heavy snow. “There are about 30 terms for the different types of snow,” he says. Experts categorise different types of snow according to how old it is (“Neuschnee”, “Harsch” or “Firnschnee”) or how dense it is (“trockener Pulverschnee” or “gebundener Pulverschnee”), with the heaviest category (“Schwimmschnee”) surpassed in density only by ice.
The Tirolean native is interested in snow for two reasons. Firstly, his family runs a hotel in the Sellrain Valley, a region popular with locals and tourists alike in winter. Secondly, he writes a blog all about snow and gives avalanche awareness seminars: www.lukasruetz.at
Avalance warning and coffee for breakfast
It is little wonder that here in Tirol so much effort goes into better understanding the subject of snow and snow conditions. The morning radio announcements by the avalanche warning service are as much a part of breakfast here as a cup of coffee. At the Innsbruck University, students of environmental engineering learn the secrets of snow. Alongside the major weather services, countless blogs on the web compete for the most accurate forecast – essential reading for thousands of people planning their day according to the weather, from farmers to skiers.
Hundreds of weather stations have therefore been set up in Tirol over the years to extract as much information as possible from the mountain sky. One of these many stations appears on the horizon as Lukas Ruetz fights his way through the snow in Kühtai. Under the summit of the Zwölferkogel mountain, an anemometer stretches out its feelers to detect gusts of wind. An ultrasound sensor sends invisible waves down to determine the depth of the snow. A device resembling a thermos flask catches precipitation. The data collected are transmitted directly to an internet platform run by the avalanche warning service. Ruetz points to the Hochwanner mountain, to the west of the Zwölferkogel. It is there that the valley opens up and the clouds often push in. “We are an area with little snow,” he says, “but snow is guaranteed.” This is no contradiction, explains Ruetz: the Sellrain Valley does not get much snow compared with other regions, but there are very few winters indeed when it gets none at all.
Mountain people have always looked up to the sky and tried to discern a pattern in wind and cloud formations. Over the centuries, superstitions and sayings have emerged like “Red sky at night, shepherd’s delight” and “On Saint Valentine’s day the snow goes away.” In reality, an accurate 14-day forecast is only possible with expertise and plenty of data. Intuition and superstition have no place in serious weather forecasting. “It is difficult to say what the weather is going to be like,” says Manfred Bauer, chief meteorologist for Tirol at the Central Institute for Meteorology and Geodynamics (ZAMG). His office is located in the flight control tower at Innsbruck airport – the perfect place for somebody who needs to keep a close eye on the sky. Bauer explains that, for there to be any chance of snow, a number of things have to happen in the right order in the right conditions in different places.
The office of the weather expert Is located in the air control tower at Innsbruck airport. It is there that the Tirolean branch of the Central Institute for Meteorology and Geodynamics (ZAMG) has its headquarters.
Every powder alarm originates somewhere over the Atlantic. “The Atlantic Ocean is our weather kitchen,” says Bauer. Above the sea, layers of air warm up, rise and absorb moisture from the water below. At altitude the air then cools down. Clouds form and a low-pressure system with areas of cold and warm air develops. The wind drives these cold and warm fronts towards Europe until they hit the Alps. The mountain peaks form a barrier which the clouds cannot pass until they have dropped enough ballast – in the form of precipitation. For Tirol this means, if the clouds come from the south or south-east, they get stuck on the main ridge of the Alps – the chain of peaks that stretches from the Reschenpass to the Hohe Tauern. Such conditions tend to bring snow to Italy’s northernmost province, South Tirol, and the neighbouring Austrian region of East Tirol. With westerly and northerly winds, on the other hand, the clouds remain on the northern side of the Alps – in the Karwendel Mountains or on the other side of the main ridge – and causes precipitation in North Tirol. If the air temperature ranges between one and two degrees Celsius, there is a good chance that this precipitation will fall snow.
Supercomputers and snow lines
Weather models have been developed to calculate what the laws of physics and thermodynamics mean for our lives – air traffic, agriculture or simply a weekend in the mountains with friends. Such models are best imagined as mathematical equations with countless variables. The more values you enter, the more accurate – but also the more complex – the process becomes. Several European countries have joined forces and send their data to the European Centre for Medium-Range Weather Forecasts, where supercomputers perform these calculations. Austria’s national weather service, the ZAMG, also operates its own supercomputer centre in Vienna. But even this concentrated computing power is sometimes not enough to produce accurate forecasts for very specific places. That is why the ZAMG meteorologists in Innsbruck sit in front of eight screens to compare satellite images, weather model calculations and data from local weather stations. As beautiful as they are to look at, Tirol’s mountains are a nightmare for weather forecasters. The wind often drives the clouds away through the wide Inn Valley. Snow-rich areas such as St. Anton, Seefeld and Hochfilzen benefit from classic winter weather fronts arriving from the north-west, because there is a particularly high accumulation of clouds in the Arlberg mountains and along the Northern Alps. Regions such as Obergurgl and Galtür, on the other hand, get a bit of snow in many weather conditions because they are located quite high and centrally in the Alps. And then there are local weather phenomena like the warm “Föhn” wind that often blows around Innsbruck. “The snow line can vary within Tirol by as much as 1,000 metres in altitude,” says Bauer.
Those who only look out of the window do not understand the weather. But equally, just staring at a screen all day also means you miss out important information. That is why Lukas Ruetz uses his laptop to check the data from the local weather stations in the mountains. He looks out for any anomalies that tell him something about the quality of the snow. If, for example, the weather station on the Zwölferkogel shows strong winds, this means gusts could have carried a lot of snow away from the western face. Assuming, that is, the sensor is working properly and has not frozen. “The other day it reported zero wind in the mountains while down in the valley there was a storm raging. That’s when you know that the data can’t be entirely correct,” says Ruetz.
Indeed, of all the many factors involved in making the weather, the wind is the most important one. “Wind is the most significant influence,” says Lea Hartl. Nobody knows better than her whether powder-loving skiers will be jumping for joy or down in the dumps in the coming weeks. She works from home in the small town of Wörgl, where she sits at a corner desk by the window. The meteorologist supplies snow forecasts to a number of clients, including PowderGuide. This website is one of the most popular places for fans of ski touring and freeriding, with the accurate and up-to-date weather forecasts among the most in-demand content. The team at PowderGuide collects data from various sources – forecasts from supercomputers, satellite images, radar and station data – and supplements them with regional reports, such as those produced by Lukas Ruetz in Sellrain. Each week Hartl advises PowderGuide on the overall weather situation, while a colleague of hers looks in detail at the snow quantities to see exactly where most powder is expected. The precipitation forecasts of the weather models indicate the amount of rain on the way, but that must be converted into snowflakes (the same amount of water can sometimes yield a lot of snow, sometimes only very little). “The temperature on the ground and the wind also play a major role,” says Hartl. If there is no wind, powder snow stays where it has fallen. If the wind blows too strongly, snow cornices are created and the danger of avalanches increases.
The meteorologist based in Wörgl supplies websites including powderguide.com with snow forecasts – using satellite data, computer models and, above all, years of experience.
Theory, data, local knowledge, experience – all these things make it possible for Hartl to weigh up very carefully whether there will be good skiing conditions in the coming days. However, she is honest about the fact that any forecast beyond about a week is very much in the realm of speculation. Advances in computer technology have taken weather modelling to a new level, but they cannot solve a fundamental mathematical problem: the longer the period being looked at, the more the variables in the equations scatter. Uncertainties which appear small at the start add up until a range of different results are obtained. “It is impossible to genuinely predict in summer what the winter will be like in Tirol,” says Hartl. Then there is the influence of climate change. Extreme weather events are on the increase. One hypothesis also assumes that the melting of ice in the Arctic will cause the polar vortex to lurch – and that this could lead to more stable weather conditions in Europe: permanent precipitation or permanent sunshine. “But there are still lots of things science does not know yet,” says Hartl.
In a world based on probabilities, there are no certainties. And even with the latest technology, the riddle of the snow cannot be solved. Maybe that’s a good thing after all. That way there is always something to talk about in winter: the snow. You will soon discover that everyone has their own secret app that’s never wrong, or friends tell stories about how they arrived on the mountain in the evening and it started snowing, all night long, and in the morning, of course, the sun was shining. “I never cease to be surprised by the weather,” says Lukas Ruetz. In 2019, for example, there was a strong Föhn wind from the east in the Sellrain Valley – “that hasn’t happened ten years. It didn’t snow anywhere else, but here in Sellrain we had half a metre in just a few hours.” Ruetz turns his back on the weather station. Today and tomorrow, he says, there’s not much chance of snow. But the day after tomorrow it should snow again, with temperatures around freezing and little wind. If it turns out as he expects, a powder day awaits.
FOR AMATEUR WEATHER WATCHERS
These websites provide the latest information on snow and weather conditions. We have learned that it is always better to have several sources of information:
The avalanche warning service shows all weather stations in Tirol: LAWIS
Current ZAMG forecasts for Tirol: ZAMG
Interactive wind data for Europe: Windy
European Centre for Medium-Range Weather Forecasts: ECMWF