Chances for a white Christmas continue to fall

MISHAWAKA, Ind. -- While many of us hope to see a cold blanket of white this Christmas morning, the forecast says otherwise.

Temperatures are forecasted to land in the upper 40s on Christmas day, meaning even if the upper levels of our atmosphere were cold enough to form snow, accumulation would be minimal to none at the surface.

Historically, 20 Christmas days since 1979 have had no recorded snowfall, with seven of the past 20 since 2012.

Over the past five years, three Christmas holidays have received no snowfall. 

Many weather-based factors contribute towards lack of snowfall on Christmas, but the increased frequency of snow-less Christmas days can be primarily attributed to anthropogenic climate change and an overall warmer climate profile over Michiana compared to thirty years ago.

As of now, the right ingredients for a white Christmas this year are missing.

Multiple kinds of atmospheric forcings on three scales of size are responsible for snowfall.

Unlike baking a cake or cooking dinner, the same ingredients do not always amount to the same results in meteorology. 

Michiana also has the unique location of being right next to Lake Michigan, further complicating snow forecasts. 

The smallest scale of weather phenomenon, also known as the microscale, can be observed by those in Michiana. Soil moisture/temperature, lake sea surface temperatures (SSTs), cloud types, etc. are just a few of many examples.

Medium scale weather events, also known as the mesoscale, mostly relate to cold/warm fronts, the land/sea breeze interaction with Lake Michigan, system snow, thunderstorms, and the jet stream.

The largest scale of weather is known as the synoptic scale and covers entire continents.

Air masses such as continental polar air or maritime tropical air are synoptic, with the boundaries between air masses known to us as fronts.

Midlatitude cyclones and anticyclones can exist on the synoptic scale or mesoscale.