Eugen, what is your role at MeteoSwiss and how did you get into meteorology?
I work at MeteoSwiss as a meteorologist and team leader in the forecasting service and do weather forecasts, warnings, aviation weather service and the whole spectrum around that. After graduating from the ETH in earth sciences, I came directly to MeteoSwiss and have been working as a meteorologist ever since. That was in 1995, quite a while ago (laughs). In between, I spent almost two years as an on-board meteorologist on two research ships around the world. The dynamics of the weather have always fascinated me. I'm also a passionate sailor, which is probably where a lot of this fascination comes from. When sailing, you are dependent on the weather and especially the wind, and you deal with it intensively.

How do weather forecasts come about?
It's an ongoing process that always starts with the current weather. You have to understand what the weather-determining systems are, such as fronts, jet stream, highs and lows. By analysing weather maps, satellite images, radar and measuring stations, we map the large-scale weather situation over Europe and the near North Atlantic. Since the weather services exchange their data internationally, we have worldwide weather data at our disposal. From the large-scale weather situation, the focus then moves to specific regions and finally to a location, for example an airport. For the local forecast, it is important to understand the overall weather situation.

 

The further out into the future I want to look, the more I have to rely on models with different strengths and weaknesses. The weather forecast is finally produced from this overall view, whereby we publish the forecast that is most probable. Since the weather models used are merely a simplification of natural processes, the challenge of making a forecast that is as accurate as possible arises anew every day. It never gets boring in the weather service - and that's what I like so much about it.

The weather is essential for flight operations. Who do you provide with what information?
The internationally standardised weather forecasts for airports, the so-called Terminal Aerodrome Forecasts (TAF), are very important for flight planning. Based on these, the first basic calculations for fuel quantity or "alternate planning" of alternative airports are made. They help pilots to estimate whether they should expect a thunderstorm, for example, and make the appropriate preparations. All cockpit crews flying to Zurich read our TAFs. For the major airports in Switzerland, these are 30-hour forecasts, which also cover every long-haul flight. At Zurich Airport alone, we have eleven weather stations that measure additional data such as cloud base and visibility. The runways have up to three measuring devices, for example to record visibility or wind in the "touch-down zone".

 

In the mornings and afternoons, we also hold a briefing in the OPC, where SWISS, Dispatch and NOC are present. We discuss the current weather and how it will develop in Zurich and Geneva over the next few hours. If there are significant weather situations worldwide, for example a tropical cyclone, we also address these. In addition, we provide air traffic control with weather data, especially to forecast major thunderstorm zones so that air traffic controllers can relieve the affected zones accordingly.

And how does the flight weather finally reach SWISS pilots?
SWISS pilots usually have their own systems on which they can access our measurement data and forecasts. From time to time they drop by MeteoSchweiz in the OPC and look at the overviews on the screens. Some information is displayed better here or they ask us questions directly. But nowadays, cockpit crews can find a lot of information on their own which they previously had to compile or ask for.

 

Is there a day in your career that has remained special in your memory from a meteorological point of view?
Definitely, yes! That was the hurricane "Lothar" on 26 December 1999, a day I was on duty. In 1999, we had already experienced very stormy (pre)Christmas days, triggered by several low-pressure areas that had moved from the Atlantic to us in Central Europe. One of these low-pressure areas subsequently developed much stronger than our models had predicted. In other words, this storm was significantly underestimated and its dimensions were only guessed at on the morning in question. That was very impressive from a meteorological point of view. Hopefully, one experiences such an enormous storm only once in a lifetime!

 

Thank you very much, Eugen, for the interesting interview!