After the heat wave, nature was unleashed in Ticino with violent storms late last week. In Switzerland, Lugano and Malcantone are the areas where lightning is most frequent.
“Lightning is the most dangerous weather phenomenon, often fatal for living beings,” says Luca Nisi, meteorologist at MeteoSwiss, adding that every year grazing animals, sometimes entire herds, are struck by lightning. “But fires and damage to infrastructure are more common.” What’s more, in the last ten years, Ticino has recorded eight times more lightning claims than anywhere else in the country, according to insurance company Axa Suisse.
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Climate models are not yet sufficiently developed to predict how climate change influences storms, says the expert. However, we know that summer heat waves and dry spells are likely to be more frequent. “These conditions are less favorable for storms that struggle to develop with warm air at high altitudes. They could therefore be less numerous.
But on the other hand, with the average temperature being higher, there will be more moisture in the air, therefore more energy. For this reason, one can imagine that the number of thunderstorms during the year will increase. “Anyway, summer fires will be more frequent, starting more easily due to drought. In addition, in these conditions, thunderstorms are characterized by a lot of wind and lightning and little rain.
Storms: a history of Ticino
The study of thunderstorms has a long history in Ticino. In 1943, a center for the study of rays, now a museum, was founded on top of Monte San Salvatore, led by Karl Berger of the Swiss Federal Institute of Technology in Zurich. In the 1950s, the Locarno Monti weather station was the first to use (originally military) radar to study storms. The station has developed algorithms to predict severe storms that are used in other parts of Switzerland.
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Researcher at the Federal Institute for Forestry Research, Snow and Landscaping WSL, in Cadenazzo, where he studies the factors linked to the outbreak of forest fires caused by lightning, Boris Pezzatti recalls that in Switzerland the only natural fires are lightning; nearly half of summer wildfires are caused there in drier years. “In Ticino, the months of July and August are the most favorable for this type of fire, which often develops from the base of lightning-stricken conifers, where a brood of needles has accumulated over the years.
These fires are often underground and their identification can be difficult in the early days because combustion is very slow at first, he explains. “In Leventina, a forester could barely make out a bit of smoke and realized there was a fire when his sole melted.” They occur mainly above 1000 meters of altitude, in exposed, rocky and often difficult to access areas. “What can make interventions dangerous, mainly because they are difficult to extinguish”, points out the researcher, noting that the phenomenon is observed mainly in the Alps; in Ticino, but also in Graubünden and Valais.
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increase in fires
Head of the forestry sector of the cantonal administration of Ticino, Roland David cites some figures: between 2000 and 2010, 12% of fires were caused by lightning, while between 2011 and 2022 it was 15.75%. In 2020, its proportion was 19% and this year, so far, 20.7%. “So yes, their numbers are increasing, but so far this type of fire has not affected large areas.”
As it does not develop on the surface, one can think of having it erased and four days later, it can start again, says the person in charge. “That’s why we take readings with a thermal camera.” During several years fighting forest fires, Ticino has developed an experience that it shares with other cantons. “We are well organised, we were faced with a high number of lightning fires this year and our interventions have been effective”, notes Roland David, specifying that sometimes these start and disappear on their own thanks to precipitation. , or some helicopter water pitches. “Like at the end of last week in Giornico. But right now, it’s man-made fires that concern us the most.”
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