Interview with Walter Hermann, Meteorologist, 14 July 2019

The weather conditions make the present championship challenging not only for the pilots but also for the weatherman. What has been the most challenging day for you so far?

The most difficult day for me so far was yesterday [day 6 of the championship] because there was a dichotomy in weather conditions: on the one hand, a strong atmospheric instability in the east and, on the other hand, stable conditions in the west. And we were exactly on the edge between the two. And the problem was to discern or to predict when and where the overdevelopment and possibly thunderstorms would occur. And if this difficult situation happens, to inform about it the competition management to the best of my knowledge and belief, because one cannot say with 100% , not even 80% certainty: “There and there thunderstorms will occur” . We could see yesterday that after initial overdevelopment in the east, the weather stabilised for a short time, during which it became possible to fly a short task but shortly afterwards again overdevelopment occurred followed by the thunderstorms and rain showers.

I have heard positive comments about the decision making on that day. People were impressed how the competition management managed to catch exactly the window to fly. Could you tell us more on how and when the decision to fly was taken on that day?

After a thorough analysis of the weather situation, I normally inform the task setter about the current weather and in cooperation with him [we develop] the possible route to be flown. Coming back to yesterday, it was difficult to establish both the start time and how long the weather would remain flyable to complete the task or when to expect an early end of thermals due to a rain shower or thunderstorm activity.

There is always a balance between, on the one hand, the desire to have as many flying days as possible in order to meet the requirement for the number of valid competition days and, on the other hand, the need to be on the safe side and not to put the pilots at risk. How do you make your judgement – based on the ‘prudence principle’?

Safety is always paramount. Whenever I give advice to the competition management, I am always aware that even my choice of words will be of decisive importance for the decision that the competition management will take. If I am 100% convinced, I express myself quite differently than when I have certain doubts. And then I convey my doubts to the competition management. In the case of yesterday it was extremely difficult and I had butterflies in my stomach the whole day about how the conditions would develop. And we were lucky yesterday, I must say. Many years of experience on my part played a certain role in the decision.

You are a glider pilot yourself and you used to fly competitions. How does your gliding experience help you in your present role?

I began flying 50 years ago, started flying competitions relatively soon afterwards and flew until 1987. After that I confined myself mainly to flying in the club as a flight instructor. I still fly crosscountry today, but most of the time I concentrate on the club activities. Of course, the experience I have gained over these fifty years helps a lot: I have about 4500 flight-hours. In addition to that, I am in regular contact with the glider pilots who I met over time. The experience from forecasting at different competitions also helps a lot. This is on the one hand. On the other hand is, of course, my professional experience since I worked as an air weather consultant with the German Army, the army aviators. There, day after day, I advised pilots, and then, unlike the German Weather Service, I got a debriefing from them and had an opportunity to verify my forecasts and learn from mistakes.

You have been acting as a meteorologist at fifty gliding competitions for more than thirty years. What do you find most challenging in this job?

The biggest challenge is certainly to always make a correct forecast (smile). That was difficult at the beginning, you go often wrong in your predictions, if you do not have much experience, this is understandable. A second big challenge is always to have a good relationship with the task setter. You have to build up trust: the task setter must have confidence in the meteorologist, and vice versa. Thanks God, I have been always lucky over the past years, with few exceptions.

And here it is also working well, I presume?

Yes, sure. Otherwise I would not be here for the third time.

For the third time in Stendal? With the same team?

With Christoph [Christophe Barniske, task setter].

You have been the Team Meteorologist of the German National Team and the German National Women’s Team at various World and European gliding championships. Is there a difference between doing a job of a team meteorologist with the national team at an international championship and being the meteorologist at a championship?

The assignment of the meteorologist at competitions is to give general advice, how the weather will develop during the day. When advising a team, there is already some forecast given by the competition management. And my job is to identify if there are any alterations that are likely to follow, from my perspective, and to inform the team members where the crunch points, the difficulties can occur today. As well as to provide information during their flying on the basis of weather reports, satellite images, radar images, partly in the encrypted form, so that the other nations do not get it, to give appropriate tips or help by their decision making and developing the tactics of the flight.

What can you say about weather conditions in Stendal? Are there any typical characteristics of the weather in the area?

Stendal and the surrounding area feature good sandy soils, where thermals can develop with even little sunlight. In addition, there is well known Fläming, a small forested hill, which helps thermals to develop more quickly if the weather conditions, especially in the northern or northeastern part of Germany, are difficult as it sometimes happens.

You will also be here in Stendal next year at the World Championship. Hopefully the weather will be better than this year.

Hopefully. This year is simply a crazy year. This is my fourth competition this year, and the fourth competition where the weather conditions are difficult. The first was in Klix, the second was the German Championship for the small classes in Zwickau and the third was in Hockenheim. And all of the competitions were at the edge in terms of the number of flying days, they had to fight to get the required number of competition days, because of the weather.

So, for a meteorologist, unlike for pilots, it is probably easier with blue thermals than when the weather is like now? 

Actually not. To predict the border between blue thermals and one to two eighth cumuli – this is sometimes very difficult. Nuances can be crucial when blue thermals were predicted and then suddenly cumuli come. And that makes a big difference in the speed of the pilots: with cloud thermals they are certainly much faster than with blue thermals. And this has an impact on the length of the task etc., etc. This is a difficult problem. It is easy when it rains (smile), or when you really have a weather with high cloud base and constantly high pressure as we sometimes had last year.

In what type of weather is it most difficult to make a forecast? In the conditions like yesterday?

This is the most difficult situation because you have a great responsibility for setting up a task when there is a risk of thunderstorms in the area. Then you really have butterflies in your stomach.

Thank you very much, Walter, for this interview and good luck!


The interview was taken by Evgenia Alexeeva.