San Juan North ============== LOW, MODERATE, avalanche danger, crusts, drifted, faceted, facets, powder , slab, slabs, sluffs, Weather Synopsis Strong northwesterly flow will ease tonight, as the shoulder of large ridge slides over Colorado. There will be some light, scattered snow north of I-70. Winds have eased in the Southern and Central mountains. Tomorrow, the turn comes for the Northern Mountains. Temperatures will warm a few degrees more Sunday. The ridge remains over the western US through the week. It might break down next weekend--expect the media to begin hyping yet another weekend storm. Weather Issued at: 2/3/2007 3:50 PM by Spencer Logan Tonight Tomorrow Tomorrow Night Forecast Forecast Forecast Temperature(°F) 0-5 18-23 10-15 Wind Speed(mph) 15-25 10-20 5-15 Wind Direction NW NNW N Sky Cover Mostly Clear Clear Clear Snow(in) 0 0 0 Snowpack Discussion One to two feet of snow fell during the last storm. There was little avalanche activity following the storm. Most of the activity was pocket-like, with smaller sectiosn of soft slab pulling out, or loose sluffs running fast and far. The snow never formed widespread slabs. That is not saying there are not slabs out there--carefully evaluate any steep slope that is drifted or has slab-like snow on the surface. With west and northwesterly winds, slabs are most likely on NE-E-SE aspects. If you do encounter a slab, it will be sitting on some sort of weak older snow. The new snow is not bonding very well to any of these surfaces. Below the new slab, some north and east slopes consist entirely of weak, faceted snow, while southerly slopes have burly crusts with facets sandwiched between them. Above treeline, the depth, strength and spatial distribution of slabs and faceted snow is variable. Avalanche Danger The avalanche danger is MODERATE on all aspects near and above treeline. Below treeline the danger is MODERATE on W-NW-N-NE-E aspects and LOW on SE-S-SW aspects. San Juan South ============== CONSIDERABLE, MODERATE, avalanche danger, crusts, faceted, powder , slabs, surface hoar, windloaded, windslabs, Weather Synopsis Strong northwesterly flow will ease tonight, as the shoulder of large ridge slides over Colorado. There will be some light, scattered snow north of I-70. Winds have eased in the Southern and Central mountains. Tomorrow, the turn comes for the Northern Mountains. Temperatures will warm a few degrees more Sunday. The ridge remains over the western US through the week. It might break down next weekend--expect the media to begin hyping yet another weekend storm. Weather Issued at: 2/3/2007 3:33 PM by Spencer Logan Tonight Tomorrow Tomorrow Night Forecast Forecast Forecast Temperature(°F) 5-10 25-30 12-17 Wind Speed(mph) 15-25 10-20 10-20 Wind Direction NNW WNW NW Sky Cover Mostly Clear Clear Clear Snow(in) 0 0 0 Snowpack Discussion Around two feet of snow fell during the storm near Wolf Creek Pass. With Friday/Saturday's strong west-northwest winds, fresh slabs formed on NE-E-SE aspects. The biggest concern is where the slabs sit on a layer of surface hoar near and above treeline on shady NW-N-NE-E aspects. Treat these slopes carefully--on Thursday, a skier triggered an avalanche on the fourth run down a 37 degree, NE aspect slope. The windslabs reside on top of a weak foundation on most aspects. That foundation is variable with older hard slabs above treeline, weak faceted snow on shady aspects below treeline and sun crusts on southerly aspects. Buried surface hoar is also sandwiched in between these crusts. Avalanche Danger The avalanche danger in the Southern San Juans is CONSIDERABLE on NW-N-NE-E-SE aspects near and above treeline. On other aspects near and above treeline the danger is MODERATE. You can probably trigger an avalanche in windloaded terrain, and there is a reactive surface hoar layer under the recent snow. Below treeline, the avalanche danger is MODERATE on all aspects.