Significantly more lightning than in summer 2018

Across Switzerland, 85,270 lightning strikes occurred this summer, compared to 53,430 in summer 2018. The most lightning strikes in the three summer months - in terms of area - occurred in the municipality of Gravesano in the canton of Ticino. The BLIDS system, the lightning information service from Siemens, registered 16.21 lightning strikes per km2 here. Among the ten localities that recorded the highest lightning density in the summer months, eight are located in the canton of Ticino. The municipality with the highest lightning density in German-speaking Switzerland is Jaberg in the canton of Bern with 11.23 lightning bolts per km2. In contrast, in more than 120 Swiss localities, no lightning strikes were recorded at all last summer. Looking at the absolute numbers at the cantonal level, the canton of Graubünden recorded the most strikes with 15,749 ground lightning bolts, followed by the canton of Ticino (13,856) and the canton of Bern (11,566). In the canton of Basel-Stadt, there were only 63 lightning strikes in the same period. By comparison, the Valais municipality of Bagnes alone recorded 1,753 lightning strikes in three months.

Determination accurate to 100 meters

The high accuracy of BLIDS is based on the Time-of-Arrival (TOA) principle. The lightning location is calculated from the difference in the times recorded in the receivers. "Whereas it used to take up to 30 seconds for information about a lightning strike to be retrievable in the system, today it takes only ten," explains Stephan Thern, head of the lightning information service at Siemens. "Today, we can pinpoint about half of the lightning strikes to within less than 100 meters." In addition to precise localization, this measurement and calculation method also makes it possible to detect polarity and current strength as well as partial flashes within an overall flash. The more precise and faster the data, the greater the protection for people, industrial facilities and infrastructure. BLIDS is used by weather services, insurance companies, and industrial and power companies, among others.

How the BLIDS system works

Every lightning bolt emits an electromagnetic signal, or electromagnetic waves. This information is registered with antennas and analyzed at Siemens' BLIDS center in Karlsruhe. The antennas are designed in such a way that they can detect from which direction the signal is coming. In combination with the information from other antennas, it is possible to determine the point of impact. The course of a thunderstorm can thus be depicted without gaps, as communicated by Siemens.

The lightning information service BLIDS uses about 160 connected measuring stations in Europe to record lightning and manages the measuring network in Switzerland, Germany, Great Britain, Benelux, Czech Republic, Slovakia and Hungary. For summer 2019, data on ground lightning was collected in Switzerland. This only includes lightning that occurs between the lower part of a cloud and the ground.

With the free BLIDS spy, interested parties can register at www.blids.de quickly and up-to-date information also about lightning strikes in Switzerland.