A refreshing summer rain, a menacing thunder storm or a full-blown hailstorm – even the weather experts can only make an educated guess at what that particular cloud in the sky really has in store.
They do, however, agree that severe rain storms and the damage they cause are on the increase – particularly in regions that are already at risk. When looking back at the end of the summer, the newspapers will report on “results battered by hail” if the season was a severe one. Some precautionary measures can, however, help to minimize hail damage.
“It goes without saying that we are pleased about every natural catastrophe that does not happen,” says Clement B. Booth, Member of the Board of Management at Allianz SE. “We are very interested in good preventative measures and provide our customers with corresponding advice. However, when a storm does happen, we are there for our customers – as an insurer, that’s quite simply our job.”
Hail forecasts not easy, but not impossible
Radar forecasts can provide hour-by-hour images of thunderstorm cells forming and can generate storm warnings. The strength of the radar signal depends on the volume and form of precipitation – strong signals suggest that hail is on its way.
“Hail usually comes hand-in-hand with a violent thunderstorm,” says Dr. Markus Stowasser, meteorologist and climate expert at Allianz SE Reinsurance. “But even when using modern forecasting methods, hail forecasting still bears considerable uncertainties.”
Paying attention to storm warnings can determine whether you are hit by a hailstorm “out of the blue” or whether you know at least a few hours beforehand that a hailstorm might, or might not, be on its way.
Hailstones measure at least 5 mm in diameter – smaller stones are sometimes called ice pellets. Hailstones with a diameter of 2.5 cm or more can leave small dents in the bodywork of cars, or damage in roof tiles or house facades (see graphic below). In extreme cases, hailstones can be the size of tennis balls, baseballs or grapefruits. Despite these comparisons, hailstones are not round and smooth, instead these chunks of ice have a rough crystal-like structure.
The main hail season in Europe, for example, is the summer: most hailstorms happen between May and September. They can also occur at other times of the year, but these storms then tend to be less heavy.
Hail damage: damaged plants, dented cars, damage to facades and roofs
This summer saw major hailstorms across Europe, in countries such as France, Germany and Switzerland. The hailstones from the July storms in Germany were the size of walnuts and left thousands of damaged cars in their wake.
After severe storms, Allianz units often set up mobile claims stations in the affected areas to ensure that customer claims are settled as quickly and unbureaucratically as possible. Partial own damage insurance picks up the costs associated with repairing dented cars.
Hail is the weather occurrence that causes the most damage to cars. Hail damage caused to a car can cost thousands of euros. For a company, the loss can be significantly higher. If hail affects an entire new car storage yard, the damage for the auto manufacturer can be immense. The agricultural sector, too, can be hit hard depending on the time of year, especially if plants are still young and vulnerable or if entire greenhouses are damaged by hailstones.
The risk of hail damage is rising
There are various reasons for the increase in the number of claims caused by extreme weather. First, numerous studies prove the link between global warming and more extreme precipitation events. Second, the volume of insured assets is on the rise – especially in Asia, which is experiencing strong growth in population figures and prosperity levels. In addition, technical developments such as solar panels mounted on roofs or housing insulation can make residential buildings more susceptible to hail damage than they were in the past, meaning that smaller hailstones can cause more damage.
Hail can occur anywhere in the world. But there are certain regions that experience more severe, or more frequent storms: namely the US, central Europe, western China and the north of India. The climatic conditions that produce thunderstorms and hail are very similar in these regions: air rises up a mountain range, intensifying the updrafts required for hail to form. If very warm, damp masses of air form at the same time, this produces extreme weather events like tornados, thunderstorms or hail.
Severe hail events which can cost over one billion euros in losses occur approximately every 150 years. Experts refer to this as “return periods”. However, two similarly severe weather events can occur within a shorter space of time, as was the case with the two “century floods” in central Europe (2002, 2013).
