The
humidity around the glacier most likely affects the snow. Desert type humidity with relatively warm days can give the appearance of a groomed slope.
Below is a link to a slope I rode on the day this image was taken. This valley (Hope Valley, California) drains directly into the desert type environment of Carson Valley, Nevada. I consider this to be a very low humidity area. The slope was smoother than some groomed runs.
http://www.snowboardgang.com/
dscf1351backcountry2007.jpg-173.html