What albedo is and how it impacts our forecasted temperatures

SOUTH BEND, Ind. -- With almost all of Michiana still having snow on the ground, a concept called "albedo" has been influencing daily temperatures. 

Albedo is defined as the ratio of reflected flux density to incident flux density referenced to a specific surface.

In a practical and physical sense, albedo is the amount of sunlight reflected by a certain body or surface back into space. 

Asphalt has the lowest surface albedo known, reflecting only three to four percent of sunlight on a clear day with no clouds. 

Freshly fallen snow has the highest albedo value, reflecting anywhere from 80% to 90% of sunlight back into space.

Like any meteorological concept, albedo values vary based on time scales, atmospheric conditions, and the "brightness" of any given day.

However, a preliminary typical amount of sunlight diffusely reflected can be found in the table below. 

Baseline albedo amounts represented as fractions. (eg. 0.03 = 3%, 0.80 = 80%) SolarGIS
Albedo plays a critical role in temperature modification, especially with a pre-existing snowpack. 

With minimal sun forecasted across the area, any sunlight that reaches the surfaces will almost be completely reflected back into space, substantially limiting heat absorption.

As a result, daily radiational cooling will be at a maximum which limits high temperature values to lower than what they would be without snow on the ground.

The lack of sunlight in tandem with the amount of snow present limits snow melt as well.

Inversely, what little heat the snow does trap is emitted back in the overnight hours, prompting a smaller daily range of maximum and minimum temperatures. 

Over the next several days, both high and low temperatures will sit in the mid to upper 30s as the snow continues to slowly melt away with milder weather moving in.

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