Saturday, February 22, 2014
The Steamboat ski area reported 1.5” mid / 2” top on the 11:20am update, though no snow was reported at 5am. Again, I’ve generally over-predicted our snowfall in these westerly wind events, especially when the atmospheric stability above mountain top is neutral or stabilizing.
Light snow is currently falling on the upper mountain, and another wave rotating around the Hudson Bay vortex will increase light snowfall this afternoon and overnight into tomorrow. We do have some cool air moving in around midnight, but generally westerly mountain-top winds are again predicted. These might affect snow quality, though wind speeds should be less than the last 2 days. I might expect 3-7” by tomorrow morning with snow ending around noon.
Current forecast have Sunday afternoon through early Tuesday dry before the final grazing wave rotating around the Hudson Bay vortex produces light snow by late Tuesday morning. There is some cool air associated with this that will help support snowfall rates, especially Tuesday afternoon, and we may see 3-6” by Wednesday morning.
Snow is forecast to diminish Wednesday, and may even end for a short time before a major northern hemispheric pattern change occurs behind the late-Tuesday wave. As happened in the warm storms of last week, the west coast ridge is forecast to be undercut by the polar jet stream, bringing relatively warm and wet weather into our area by the end of the workweek.
The first of these waves is timed for Thursday with pieces of another stronger wave affecting our weather by the weekend. Pattern changes are notoriously difficult to predict, especially when a dominant pattern like the west coast ridge is forecast to weaken and break down, so I expect changes to this forecast as we get closer to the event. It does appear that this pattern may persist for a week or so, bringing significant precipitation to the moisture-starved California area, while first the Midwest and then the East Coast are tormented by more arctic outbreaks during the workweek.