JR’s San Juan Mountains Weather & Snowpack Report. 12/27/10. 09:30
A fast moving short wave has brought a trace to several inches of snow to the northern San Juans this morning. Split flow develops tonight with imbedded short waves, associated cloudiness and maybe an inch or two more snow. A Pacific NW storm with deeper moisture begins to approach on Tuesday then shifts to southerly flow holding more energy late Tuesday evening.
By Wednesday we’ll see a cold front and a deep long wave trough digging into the area on west/south west flow with strong jet support that looks interesting, although past models have overplayed jet influence with little snow production this season according to NWS.
This system has colder temperatures associated with it and the models show the trough turning into a closed low over Co./N.M Thursday, slowing down and potentially bringing good snow amounts favoring the south and west San Juans. By Friday the back edge of the trough will push through the area changing wind and orographic influence from SW to N/NW flow favoring the north side of the range. Looks like a good storm period into the weekend.
All of the past weeks storm totals are resting upon a thin, weak snowpack that saw a big natural cycle, but is slowly tightening up and becoming more difficult to trigger by ski or board. The Avalanche Danger is CONSIDERABLE on W-N-E above TL and MODERATE below TL on the SW-S-SE. The SW winds loaded the northern aspects with slab conditions so pick your terrain and runs wisely..