AVALANCHES: Good view of recent avalanche cycle from the weekend’s storm. About a dozen soft slabs, D1 to D1.5’s, failing at the storm interface on northwest to east-northeast aspects. (Several on Mt. Axtell, Carbon Peak, East bowl in the Anthracites, Northwest bowl in the Anthracites, above Coal Creek, and in the Anthracite Range). Most of these were near/below treeline, and two were above treeline near Ohio Peak. Two notable slides had larger crowns, and looked to have failed on older, deeper layers, several feet deep and D2 in size. One was a heavily crossloaded slope on Mt Axtell, NE aspect below treeline. The other was a north facing bowl below Ohio Peak. I think the latter failed today. There were dozens of dry loose avalanches, D1 in size, on various aspects, and a number of natural wet loose avalanches ran today on southerly aspects, but didn’t see any slab avalanches on these aspects in the Ruby Range or Peeler Basin.
WEATHER: Clear skies. Calm winds. High of 32 at 10k.
SNOWPACK: Snow surfaces became moist on E through S through W aspects today.
UPLOADS:
Date: 02/24/2015
As the closed low moves west into central Arizona, we’ll see cloud cover decrease today under light winds. The pattern shifts to northwest flow through the rest of the week as a large scale trough moves across Canada, sending a series of shortwaves to our north. We’ll see cold air, increased winds, and a continued chance for snowfall into the weekend.
High Temperature: 25
Wind Speed: 2-12 mph
Wind Direction: NE
Sky Cover: Decreasing clouds
Snow: 0
Low Temperature: 15
Wind Speed: 8-18 mph
Wind Direction: NW
Sky Cover: Increasing clouds
Snow: 0-1″
High Temperature: 22
Wind Speed: 13-23 mph
Wind Direction: NW
Sky Cover: Overcast
Snow: 1-3″
WEATHER: Overcast sky was breaking up in the afternoon. A frew s-1 snow showers through out the day. Strong solar through thin clouds was creating a green housing effect. Calm wind throughout the day.SNOWPACK/AVALANCHE OBS: Green housing and some solar warmed the snow surface and created a 1-2cm crust by the afternoon. Had pits along the way found generally good bonding between the new/old snow interface as well as the new snow lacking a cohesive slab. HST at 11,000ft was 40-45cm. BTL south facing slopes grater then 30 degrees and below 10,000ft where bare of snow before this storm.
AVALANCHES: Observed ~10 natural soft slab avalanches failing on the storm interface (near surface facets) mostly below treeline and a few near treeline slopes on North and Northeast aspects. Slabs were generally 40 to 150 feet wide, 12″-16″ deep, and ran a couple hundred vertical, not large enough to bury someone. Observed slides in Schuykill Ridge, Climax Chutes, Happy Chutes, and Peeler Basin. (SS-N-R1-D1-I). One exception was a wider and longer running slide on Schuykill Ridge, maybe 300-400 feet wide and ran 1,000 vertical, D2 in size.
We skier triggered about 15 similar slides, all BTL on N/NE aspects on Schuykill Ridge. D1 in size on relatively small terrain features. Slides behaved like storm slabs in that they didn’t propagate beyond the steep rollovers and wouldn’t trigger remotely.
WEATHER: Overcast to broken skies. Calm winds. Very light snowfall (S-1) tapered by 10:00 a.m. Mild temperatures.
SNOWPACK: 12″ to 16″ of fist hard storm snow, zero wind affect. Formed a soft slab over widespread near surface facets on N/NE, thin crust over facets on E, and thick crust on S. Storm snow was very reactive anywhere that it was on near surface facets. Widespread shooting cracks up to 100 feet, some collapsing, and anything over 36 or 37 degrees was almost a sure bet it would slide. No signs of instability on south aspects and got one collapse on an east aspect, under the thin crust. Below the storm slab, the snowpack was faceted throughout, and didn’t feel persistent slab structure, even near ridgetop. However, we didn’t poke around under the large, windloaded start zones that are likely to be holding stronger mid or upper pack.
UPLOADS:
Schuykill Ridge. NE aspect  SS-N-R1-D1-I
Schuykill Ridge, NE aspect. Â SS-N-R2-D2-I
Skier triggered soft slab. Â Schuykill Ridge. N or NE aspect BTL
Skier triggered soft slab. Â Schuykill Ridge. N or NE aspect BTL
Skier triggered soft slab. Â Schuykill Ridge. N or NE aspect BTL
Skier triggered soft slab. Â Schuykill Ridge. N or NE aspect BTL
Natural soft slabs on Peeler Peak. Â SS-N-R1-D1-I
Skier triggered soft slab. Â Schuykill Ridge. Â NE aspect BTL
NAME: Jeff, Donny
DATE: 20150222
ACTIVITY: Avy L2
Date: 2/23/15
Light snow during the day Sunday but steady moderate snow overnight, becoming light near sunrise. The 24 hour totals are 13″ new with 0.87″ water and now at the winters deepest snowpack of 48″. Thankfully no wind. Currently overcast and calm with very light snow and mild- between 16 and 18ºF overnight. billy bar
Date: 02/23/2015
Yesterday’s snowfall was a bit later and lighter then forecasted but we still did well with a general foot of snow so far. A low pressure system south of Colorado is producing excellent snowfall in the San Juan mountains. That same moisture is carrying over to our mountains too and we’ll see continued snowfall today. The big forecasted player in enhanced snowfall for our mountains was a convergent zone the set up to our west and hasn’t moved over our areas to produce the significant snowfall that was in the forecast yesterday. On Tuesday the low pressure to our south will be moving out of the area and we’ll see a dryer transition day. By Wednesday a shortwave will be dropping into Northern Colorado that should keep us seeing snowfall later this week.
High Temperature: 22
Wind Speed: 5-15
Wind Direction: S
Sky Cover: Overcast
Snow: 2-5
Low Temperature: 18
Wind Speed: 0-10
Wind Direction: SE, S
Sky Cover: Overcast
Snow: 0-2
High Temperature: 25
Wind Speed: 2-12
Wind Direction: N, NE
Sky Cover: Decreasing clouds
Snow: 0
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AVALANCHES: None, except minor sluffing.
WEATHER: Steady S1 through the day, increased to S2 around 4:00. Calm winds. Overcast. Mild Temps
SNOWPACK: By 4pm, 8″ of storm snow at ridgeline and 4″ of snow at valley bottom; no wind affect. About 2-3″ of new through the day. New snow was too shallow and incohesive for slab formation; no storm slab concerns (yet). Falling on near surface facets on North/Northeast aspects. On these slopes, the snowpack felt almost entirely faceted in many places, except as we got higher near treeline, where some lingering stronger midpack prevailed. 5 pits, never saw surface hoar, but fist hard facets in every pit in the upper snowpack. The only pit with propagating results was a windloaded feature where a shallow, persistent slab from recent wind events was over near surface facets. On East and Southeast aspects, the new snow is on meltfreeze crusts. Warm snow seemed to be bonding decently, but there were a few slopes with thin crust /facet/crust sandwich (Feb 20th and Feb 16th crusts), and these produced small, localized cracking. Bottom line – plenty of weak layers out there under this storm snow, just need more snow/wind loading.
