High cirrus began invading western Colorado early this morning just ahead of a Pacific storm that will push through the west as an open trough on slight SW flow. The San Juans especially the southern SJ’s will be in the main flow late tonight through late tomorrow with up to 2′ of snow possible. Storm dynamics including a stalled surface cold front, high winds (polar jet-165 k overhead) and decent southern moisture push the storm potential. The moist subtropical jet should meet the cold front sliding south Tuesday morning causing a significant precipitation event for the southern SJ’s.
The south San Juans could receive the brunt of this moist storm with 12-24″ or more at Wolf Creek. The cold front should drop air temps allowing snowfall instead of rain in the lower elevation valleys (5 – 7,000′), something unusual this winter.
Following this storm a dry pattern for the first 10 days of March looks real. The storm track moves into the northern Rockies and B.C.