The amount of snow that falls each winter can vary widely from year to year. Differences in weather patterns can cause heavier than normal or lighter than normal accumulations. Topography and the proximity of bodies of water can also have an effect on the amount of snowfall. Recent changes in otherwise predictable weather patterns are causing controversy over whether the burning of fossil fuels is the source of these alterations in historic patterns.
What Causes Heavy Snowfalls?
A number of factor influence the amount of snowfall in a given area, including the presence of convective clouds, heavy water vapor content in the air and strong updrafts that cause the snow to drop from the bottom of the clouds. Heavy snows often occur around lakes and in mountainous regions because of the atmospheric conditions in these areas that favor snowfall. Orthographic effects occur when air rises up the windward side of mountains, pushing moist air into the cloud bottoms. This effect leaves the leeward side of the slopes drier with less precipitation.
World Record Snowfalls
Determining records for weather extremes around the world can be difficult because data collection is unreliable or non-existent in some remote regions. In addition, information is calculated in a number of ways, such as over 24 hours or over a winter season, that make it difficult to compare figures. The largest unofficial snowfall data is 1,140 inches of snow that fell at Mt. Baker ski area in Washington during the 1998-99 season. The officially recognized largest snowfall in 24 hours occurred at Silver Lake in the Colorado Rockies on April 14-15 in 1921 when 75.8 inches fell.
Record Cold and Snow in Europe
Over 2010 and 2011 winters, Europe saw some of the coldest temperatures on record for the continent, with cold temperatures and the heaviest snowfall they have seen since 1981. Snow covered normally warmer countries such as Italy, leading scientists to suggest that the abnormally long-lasting high pressure cell hanging over Greenland may be a result of more than just a freak weather pattern.
Climate Change Effects on Snowfall Amounts
The ongoing data about global warming and subsequent climate change has caused scientists to postulate that weather patterns will cause increased snow cover in the future in North America. This effect is also expected to increase the severity of winters in Europe and Russia as the Arctic ice caps melt and polar winds bring more moisture to the atmosphere.