The hail season 2020 has been exceptionally calm so far. After very nice weather in March/April we had rather cooler weather with lower temperatures at the beginning of our season in May/June. Therefore the danger for thunderstorms with hail was rather low so far. With rising temperatures, the danger of hail is now much greater, which has been observed in the last few days. So far, we have carried out eleven flights during the 2020 season.
We work very closely with a weather service which provides us with several meteorologists from the end of April to mid-October. They permanently observe the weather and determine the operational readiness of the pilot and the cloud seeder. Every morning at 8:00 a.m. we receive a detailed weather report for the protected area, in which the meteorologist explains what will happen in the weather and especially if and when there is a danger of hail and when a pilot has to be ready. Thereupon the pilot prepares the aircraft and contacts the meteorologist again to clarify whether there were any changes to the original assessment. The meteorologist then gives the launch command to the pilot and tells him in which direction to fly. Pilot and meteorologist are in constant contact until the rest of the day. From the air, the pilot can see the clouds that have to be vaccinated very clearly. In addition, he has a tablet on board with which he can follow the weather over the entire protected area very closely via a satellite connection. He flies to the cloud, "crosses" under the cloud - thus looking for the updraft area and then circles under the cloud and starts the vaccination process.
With our work we support the natural process of ice formation in a thundercloud. So in addition to the natural ice nuclei such as dirt particles in the air, we bring artificially produced ice nuclei into the thundercloud. We do this very purposefully by circling with our airplane under the cloud in the updraft area of the thunderstorm and vaccinating the cloud with the artificial ice nuclei. These then enter the cloud together with the natural ice nuclei, where the hail originates. A larger number of ice nuclei then produces more small-grained hail, which can then melt again easily until it reaches the ground.
This method is also used internationally in many similar projects. There are studies from an artificial environment (climate chamber) which prove that our application principle works. There is not a single study that proves the opposite and proves that hail prevention does not work the way we practice it.
«Through our activities, we see time and again that thunderstorms during our flights quickly diminish or even do not develop so strongly in the first place.»
Switzerland undertook the well-known large-scale experiments in the 1980s and was already relatively well advanced in hail control at that time. However, the topic was then somewhat lost sight of again, as the large-scale trials were not successful from a scientific point of view. However, the findings of the large-scale tests were used internationally as an opportunity to revise the methods and adopt a different approach. In global terms, hail protection by means of missiles is now only rarely used, but this was the reason for the development of the approaches we know today.
Switzerland now also has the advantage that in southern Germany they have already gained some experience with cloud vaccination by plane. I also have a small team of scientists working for me who have been working on the topic of vaccination material for more than 30 years. Their findings are also incorporated into our products, which we use for application, from which Switzerland also benefits. The ETH is now in the process of conducting a study as an independent institute to examine the effectiveness of our mission flights. Through our activities, we see time and again that thunderstorms during our flights quickly diminish or even do not develop so strongly in the first place.