A significant change in the flow pattern happened on Friday night, the deepening upper level trough pushed south from the Gulf of Alaska giving us cooler temperatures and a stronger jet stream.
This trough will keep moving southward in the next couple of days.
From Colorado, CAIC: Early Season Conditions
From 1986, Steamboat Patrol Video: Old School
More winter outlooks 2012-2013: NOAA
Why more people are dying in avalanches: ESPN
