Canada’s Coast Mountains stretch about 1,000 miles (1,600 km) from Yukon, Alaska, USA to the Frasier River in Southern British Columbia, Canada. They are a part of the massively long “American Cordillera”—a group of peaks that run along western North America, Central America, and Antarctica.
Snow is a prime feature of the Coast Mountains, accumulating along the entire range, both peaks and valleys, in the wintertime. Snow depth, moisture content, and other characteristics are the result of many climate features, including air temperature, wind, atmospheric moisture, precipitation amounts, and storm frequency. As spring arrives and temperatures warm, the snowpack begins to melt, feeding rivers and streams and providing vital water to surrounding regions, filling lakes and water reservoirs, irrigating agricultural land, and providing for other needs of humans and the ecosystem.
On April 20, 2021, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a true-color image of the Coast Mountains north of the island of Vancouver. The ecoprovinces recognized by British Columbia that are captured in this image include Coast and Mountains (west), the Central Interior (north), and the Southern Interior. While substantial snow remains on the highest elevations, spring melting is well underway with many valleys in the interior snow-free, especially in the Southern Interior. Some lakes in the Central Interior, however, remain ice-covered.
According to British Columbia’s Environmental Reporting BC webpage, snow depth and the water content of snow both significantly decreased in three of B.C.’s ecoprovinces between 1950 and 2014. Snow depth and snow water content decreased at a rate of 11 and 7 percent per decade in the Southern Interior, 10 and 5 percent per decade in the Central Interior, and 7 and 5 percent per decade in the Southern Interior Mountains.