Regional And Mesoscale Meteorology Team
Daily Satellite Discussion
Friday November 7, 1997
Possible reasons snow covered areas will appear different:
1. Dark regions may have no snow at all and will appear darker than locations having received snow.
2. Regions may appear relatively dark if the snow depth was relatively small. Deeper snows cover most surfaces and it takes longer to melt enough snow to reveal the darker surfaces below than for shallow snows.
3. Regions may appear relatively dark if they have more vegetation. Limbs and leaves of trees do accumulate snow, but this snow is easily removed by wind and the snow usually will not completely cover all branches and leaves. This is the case for the vegetation lined rivers which run through the plains of eastern Colorado (such as the Arkansas which runs east from Pueblo, and for the South Platte running east from Greeley) This is also the case in the mountains where evergreen trees are dense. Note that Conifer (within the foothills) appears darker than the eastern plains of CO, yet Conifer received nearly a foot more of snow than the plains.
4. Cities may appear darker due to the localized vegetation there and also the amount of paved surfaces (roads and rooftops) that generally shed their snow faster than the unpaved ground (note the cities identified in the image appear as darker spots).
There are likely more possibilities than those I have presented here. The point is that relative darkness of different locations is not sufficient information to confidently diagnose relative snow depths.