san bernardino pass

Snow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by external pressure. Snowflakes come in a variety of sizes and shapes. Types which fall in the form of a ball due to melting and refreezing, rather than a flake, are known as graupel, ice pellets or snow grains. Snowfall amount and its related liquid equivalent precipitation amount are determined using a variety of different rain gauges.

The process of precipitating snow is called snowfall. Snowfall tends to form within regions of upward motion of air around a type of low-pressure system known as an extratropical cyclone. Snow can fall poleward of these systems' associated warm fronts and within their comma head precipitation patterns (called such due to the comma-like shape of the cloud and precipitation pattern around the poleward and west sides of extratropical cyclones). Where relatively warm water bodies are present, for example due to water evaporation from lakes, lake-effect snowfall becomes a concern downwind of the warm lakes within the cold cyclonic flow around the backside of extratropical cyclones. Lake-effect snowfall can be locally heavy. Thundersnow is possible within a cyclone's comma head and within lake effect precipitation bands. In mountainous areas, heavy snow is possible where upslope flow is maximized within windward sides of the terrain at elevation, if the atmosphere is cold enough.

The Swiss Alps (German: Schweizer Alpen, French: Alpes suisses, Italian: Alpi svizzere, Romansh: Alps svizras) are the portion of the Alps mountain range that lies within Switzerland. Because of their central position within the entire Alpine range, they are also known as the Central Alps. The highest summit in the Swiss Alps is Monte Rosa (4,634 metres) near the Swiss-Italian border. The highest mountain which lies entirely on Swiss territory is the Dom (4,545 metres). Other main summits can be found in the list of mountains in Switzerland.

Since the Middle Ages, transit across the Alps played an important role in history. The region north of the St. Gotthard Pass became the nucleus of the Swiss Confederacy in the early 14th century.

San Bernardino Pass (elevation 2,066 metres or 6,778 feet) is a high mountain pass in the Swiss Alps connecting the Hinterrhein and the Mesolcina (Misox) valleys between Thusis (Graubünden) and Bellinzona (Ticino). Located in the far eastern side of the Western Alps it is not to be confused with the Great St. Bernard Pass and the Little St. Bernard Pass. The top of the pass represents both the Italo-German language frontier and the watershed (drainage divide) between the Po basin and the Rhine basin.

The route first became important as a mule track in the fifteenth century when the route between Thusis and Splügen was known as the Via Mala. A road for wheeled vehicles was opened in 1770; this road was significantly improved between 1821 and 1823, financed in part by the Kingdom of Sardinia, keen to improve a trade route connecting Genoa and Piedmont to the Graubünden that was not directly controlled by Austria.