How does a snow storm come about


From the New England states in the northeastern United States, including Maine, New Hampshire, Vermont and Massachusetts, we keep getting reports and pictures of snowstorms that bring all traffic to a standstill. The high-tech world is downright stuck in the → snow. These catastrophic snowstorms are also called → blizzards there. In addition to snow, they bring icy → wind, the dreaded freezing rain and permafrost. In the north and northeast of the USA, heavy snowstorms rage almost regularly. These blizzards are usually preceded by mild weather. They are caused by strong ingress of cold air from the north and north-west on the back of low pressure areas. A slow drop in air pressure and rapidly dropping temperatures herald the icy winter storms. The wind reaches storm force with wind speeds between 60 and 75 km / h.

As a result of their large amounts of snow, but above all through snow drifts, snowstorms cause locally catastrophic traffic conditions and cause enormous supply problems. In addition, there is freezing rain and permafrost. The sometimes three to four meter high snowdrifts often cut off entire cities from the outside world.

In January 1998, the worst winter storms in decades raged in Canada for days. Several thousand soldiers were deployed to repair the damage caused by the heavy ice and snow storms. The Canadian Defense Minister Art Eggleton spoke of the largest crisis deployment of the army in the history of Canada. The northeast of the USA was also badly affected by snow masses and freezing rain. The long-lasting winter storm in eastern Canada in January 1998 caused hundreds of Montreal residents to leave their cold homes and seek refuge in community centers and schools. Montreal and Ottawa airports were closed on January 9, 1998. Rail traffic between Toronto and Quebec was discontinued. Numerous power lines collapsed under the weight of the ice masses. Schools, shops and authorities remained closed. As in Canada, winter chaos prevailed in the northeastern United States. The US President Bill Clinton declared five districts in the US state of New York to be emergency areas. Even two weeks after the severe winter storms in Canada, around 240,000 households were without electricity. In the greater Montreal area, police went door-to-door in mid-January to place residents in emergency shelters. 24 people were killed as a result of the catastrophic weather conditions.

Heavy snowstorms in the winter of 1978/79 and in the spring of 1979 also caused catastrophic conditions in northern Germany. Schleswig-Holstein was worst affected. To ensure supplies and snow removal operations, a total driving ban was imposed on December 30, 1978. Schleswig-Holstein was well prepared for the forces of nature on the part of the sea through extensive coastal protection, but not for a state-wide emergency caused by snow. On December 28, 1978, a stable high pressure area over Scandinavia and a low over the Rhine met. The consequences were strong wind fields and squalls. Due to a drop in temperature, long-lasting rains first turned into freezing rain and then into heavy snowfall. It snowed for days without a break. As a result, communication in Schleswig-Holstein was largely interrupted. As a result of the freezing rain, overhead lines were literally sheathed in ice. This made them so heavy that they simply tore apart. Even high-voltage pylons buckled like matches. As the energy supply subsequently collapsed, chaos threatened fully technical agriculture with air-conditioned stables. More than 5,000 people had to be rescued from vehicles and trains, and traffic completely collapsed. 17 people found death in the snow. Bundeswehr armored recovery vehicles, helicopters and clearing equipment with aid teams from other federal states provided assistance, and the farms, which were largely cut off from the outside world, were supplied with emergency power generators. A few weeks later the snow chaos was repeated in northern Germany.

On February 13, 1979, meter-high masses of snow piled up over the "snow of yesterday". Traffic connections were paralyzed again for almost a week. In contrast to the previous snow disaster, however, the deployment of the auxiliaries and the alerting of the population went much better. In addition, the farms were still equipped with emergency power generators, so that there were hardly any problems here. The state of Schleswig-Holstein drew the lesson from these events that adequate precautions must be taken with appropriate emergency plans not only for coastal protection, but also for other extensive natural forces.