The Winter of Terror was a three-month period during the winter of 1950–1951 during which an unprecedented number of

avalanche An avalanche is a rapid flow of snow down a slope, such as a hill or mountain. Avalanches can be set off spontaneously, by such factors as increased precipitation or snowpack weakening, or by external means such as humans, animals, and eart ...

s took place in the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Swi ...

along the Austria–Switzerland border. The series of 649 avalanches killed over 265 people and caused large amounts of damage to residential and other human-made structures.

Damage and casualties

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populou ...

suffered the most damage and loss of human life with 135 killed and many villages destroyed. Thousands of

acres The acre is a unit of land area used in the imperial and US customary systems. It is traditionally defined as the area of one chain by one furlong (66 by 660 feet), which is exactly equal to 10 square chains, of a square mile, 4,840 square y ...

of economically valuable forest in both Austria and Switzerland, were also damaged during the period. The

Valais Valais ( , , ; frp, Valês; german: Wallis ), more formally the Canton of Valais,; german: Kanton Wallis; in other official Swiss languages outside Valais: it, (Canton) Vallese ; rm, (Chantun) Vallais. is one of the 26 cantons forming the Sw ...

canton of

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

suffered 92 human deaths, approximately 500

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Adult females are referred to as cows and adult ...

deaths, and destruction of 900 human-made structures. As in Austria, economically important forests were also damaged during the period.Tufty, B. (1978) ''1001 Questions Answered about Earthquakes, Floods, Avalanches and Other Natural Disasters'', Courier Dover, p133, The Swiss town of

Andermatt Andermatt ( rm, ) is a mountain village and municipality in the canton of Uri in Switzerland. At an elevation of above sea level, Andermatt is located at the center of the Saint-Gotthard Massif and the historical center cross of north-south and ...

in the Adula Alps was hit by six avalanches within a 60-minute period, resulting in 13 deaths.

Causes

The period is thought to have been the result of atypical weather conditions in the Alps: high

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...

due to the meeting of an

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the "Old World" of Africa, Europe a ...

warm front A warm front is a density discontinuity located at the leading edge of a homogeneous warm air mass, and is typically located on the equator-facing edge of an isotherm gradient. Warm fronts lie within broader troughs of low pressure than cold fr ...

with a polar

cold front A cold front is the leading edge of a cooler mass of air at ground level that replaces a warmer mass of air and lies within a pronounced surface trough of low pressure. It often forms behind an extratropical cyclone (to the west in the Northern ...

resulted in 3–4.5 metres of

snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...

being deposited in a two- to three-day period. More than 600 buildings were destroyed and over 40,000 people were buried under snow.

References

{{Authority control 20th-century avalanches 1951 in Austria 1951 in Switzerland 1951 in Italy

Winter Winter is the coldest season of the year in polar and temperate climates. It occurs after autumn and before spring. The tilt of Earth's axis causes seasons; winter occurs when a hemisphere is oriented away from the Sun. Different cultures ...

1951 natural disasters Winter weather events 1950 in Austria 1950 in Switzerland 1950 in Italy 1950 natural disasters Avalanches in Austria Avalanches in Italy Avalanches in Switzerland