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Storm front on a Doppler radar screen

The term storm stands for a strong wind event .

Meteorological definition

Storm in the North Atlantic, 9..12 Bft.
Wave height 12 m
Winter storm in the North Atlantic : high seas and water over deck and hatches

Winds with speeds of at least 20.8 m / s (74.9 km / h) or 9 Beaufort are referred to as storms . A storm with a wind speed of at least 32.7 m / s (117.7 km / h) or 12 Beaufort is known as a hurricane . In between one speaks of a severe storm at 10 Beaufort and a hurricane-like storm at 11 Beaufort . If the wind only reaches storm strength for a short time (for a few seconds), one speaks of a storm gust . As a rule, a storm is also associated with heavy rains , which is why the term is often used colloquially as a synonym for a heavy shower or a thunderstorm , but both are only side effects or special cases of a storm. At sea there is also high waves for the wind-related the term storm in use, with less emphasis on the mostly simultaneous precipitation. Depending on what stirs up a storm or what it occurs together with, one speaks of a snow storm , hail storm , sand storm ( Buran ) or dust storm . In the mountains, foehn storms occur as dry wind events .

A differentiation according to the season is sometimes used, for example one speaks of a winter storm . Such distinctions are particularly important in the impact assessment in the case of agricultural and forestry damage ( e.g. crop failures after floods, wind breaks and the risk of bark beetles ).

Other types of storm are the tornado , sometimes called a (small) trombone , tornado , waterspout or twister, as well as the snowstorm blizzard .

In coastal regions, the interaction of storms and tides can lead to storm surges .

Origin and appearance

Storm winds can arise when high pressure gradients (high pressure differences over a relatively short distance) occur. These are often present as storm lows in the area of ​​influence of strong low pressure areas. Storm winds can also arise from topographically determined channeling of the wind, for example as valley winds in narrow valleys.

Storms often occur over the ocean as there is less ground friction . So the winds can develop better than on the mainland and reach storm force much more frequently. In addition, tropical cyclones , i.e. hurricanes and typhoons , can only arise above the sea and weaken rapidly over land masses.

Hazards, damage and storm insurance

Storm damage in the High Tatras , Slovakia
An approaching storm over the North Sea off Sylt

Direct storm damage mainly affects the covering of roofs or other wind movements; in wooded areas, property damage is also caused by knocked over trees ( storm wood ). Indirect damage is also important, for example from the deposition of sand on agricultural land in the event of a sand storm or damage from hail. For people, the greatest danger is from objects flying around, falling branches and falling trees, and possibly from damaged power lines above ground, so it is usually safest to stay inside buildings during the duration of a storm.

Many insurance companies  only pay for storm damage - if storm damage insurance has been taken out - when the wind has demonstrably reached wind force 8 ( stormy wind , the insurance term "storm" is to be interpreted differently here). The general insurance conditions for residential buildings (Germany about § 8 ​​VGB 88) understand storms to mean a weather-related air movement of at least wind force 8. The definition in German § 3 (3) a FEVB is similar, according to which it is an atmospheric air movement of at least wind force 8 must act according to Beaufort. The insurance law term thus deviates from the meteorological terminology. According to the relevant Beaufort scale, strength 8 means "stormy wind that breaks branches of trees and makes walking outdoors considerably more difficult".

The policyholder of a building insurance who claims the presence of a storm can be exposed to difficulties of proof in borderline cases. To prove storm damage, it is of course not necessary that proof of direct impact of an air movement of at least wind force 8 on the insured building is provided. Many newer insurance conditions make it sufficient that storm damage has occurred (also) in the neighborhood. Otherwise, according to the Karlsruhe Higher Regional Court, it is even sufficient that the building was damaged by air movements and that a wind force 8 storm occurred in its immediate vicinity at the same time.

In the shipping industry , weathering can avoid dangers in a storm . There is a particular danger in container transport , where losses at sea occur again and again. Allegedly, work has been going on for years to improve the situation.

Historical storm events and their damage


The world's largest insurance claims:


Major storm catastrophes in Austria:

  • November 8, 1982, the "blow dryer of the century"
  • February / March 1990 Vivian and Wiebke (Spitz Wiebke with 147 km / h (Hörsching), joint damage three billion schillings (approx. 218 million euros))
  • April 5, 1997, combined with heavy snowfall in the next few days
  • February 5, 1999, Lara with storm peaks of 130 km / h (Vienna Airport)
  • December 26, 1999, hurricane Lothar
  • March 19, 2001, Storm Emma (one dead and two seriously injured in Lower Austria)
  • December 15, 2005, Storm Dorian
  • January 18, 2007 Hurricane Kyrill , 216 km / h (Gaisberg), 100 million euros in damage, numerous fatalities in the repair process
  • 26.-27. January 2008 Storm Paula , 230 km / h (Schneeberg), major damage, especially in Styria
  • 1st – 2nd March 2008 Emma , 222 km / h (Wendelstein)
  • October 29, 2017, Storm Herwart , up to 179 km / h, thousands of households without electricity, major damage throughout Austria


Major storm catastrophes in Germany:

  • November 13, 1972: Hurricane Quimburga , 245 km / h (Brocken), over England, Benelux, Northern Germany, 73 dead, damage approx. 1.34 billion DM
  • 25-26 January 1990: Storm Daria , 130 km / h, 8 dead in Germany, damage approx. 4.4 billion euros
  • December 26, 1999: Hurricane Lothar , 272 km / h ( Hohentwiel ), 13 fatalities in Germany and more being repaired, damage approx. 1.2 billion euros
  • January 18, 2007: Hurricane Kyrill , 200 km / h ( Wendelstein ), 13 fatalities and more in the repair work, damage amount 2.3 billion euros
  • March 31 - April 1, 2015: Hurricane Niklas , 192 km / h ( Zugspitze ), 9 fatalities, damage amount approx. 750 million euros
  • January 18, 2018: Storm Friederike , 205 km / h as a top gust ( Brocken ), 8 fatalities, damage amount (estimated) 500 million euros
  • 9-11 February 2020 Hurricane Sabine , 178 km / h as a top gust ( Feldberg ), 4 dead, damage amount (estimated) 600 million euros

Web links

Wiktionary: Sturm  - Explanations of meanings, word origins, synonyms, translations
Commons : Storm  - Album with pictures, videos and audio files

Individual evidence

  1. OLG Karlsruhe, judgment of April 12, 2005 , Az. 12 U 251/04, full text.
  2. Wetterlexikon - Hurricane entry on
  3. a b c d e Natural and anthropological catastrophes 2001: Man-made damage of a new dimension. In: sigma 1/2002, Schweizerische Rückversicherungs-Gesellschaft, p. 23 ( web document  ( page no longer available , search in web archivesInfo: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , pdf)@1@ 2Template: Toter Link /  
  4. Definitions & overview of the last decades of heavy storm events in Austria , analyzes of extreme weather events from Austria 2002–2006,
  5. Since 1990: Again and again strong storms in Lower Austria ( Memento from July 17, 2012 in the Internet Archive )
  6. Most powerful storms over Austria from 1990 to 2005 , Salzburger Nachrichten online, January 18, 2007
  7. K. Frey: Der “Jahrhundertföhn” from November 8, 1982. A synoptic view. In: Meteorologische Rundschau 37 (1984), pp. 209-220