Mountain Weather February 26, 2015

CB Avalanche Center February 26, 2015Weather

Date: 02/26/2015

We’ll see a brief lull in active weather this morning before another extended period of snowy weather kicks carrying us into next week. The previews start this afternoon as the next shortwave moves in from the northwest, issuing the first round of snowfall favoring Kebler and Paradise Divide. Unstable air will fuel showers on Friday morning, before the main feature begins to set up for the weekend. A large trough will tap into healthy amount of moisture and drive it over our region under southwest flow, fueling significant snowfall with good dynamic support. A foot or more seems reasonable by the end of the weekend.

Today

High Temperature: 18
Wind Speed: 5-15
Wind Direction: W, NW
Sky Cover: Increasing clouds
Snow: 0-3″

Tonight

Low Temperature: 5
Wind Speed: 5-15
Wind Direction: SW, W
Sky Cover: Mostly Cloudy
Snow: 1-4″

Tomorrow

High Temperature: 20
Wind Speed: 10-20
Wind Direction: SW, W
Sky Cover: Overcast
Snow: 1-4″

Coney’s Obs

CB Avalanche Center February 26, 20152014-15 Observations

LOCATION: Kebler Pass Area
DATE OF OBSERVATION: 02/25/2015
NAME: Evan Ross

SUBJECT: Coney’s Obs
ASPECT: North East
ELEVATION: NTL/BTL

AVALANCHES:

WEATHER: WEATHER: Mostly Cloudy with several snowfall bursts throughout the day. About 1″ new near the top of Coney’s at 2pm. Light to moderate winds where down valley at BTL elevations and westerly at ridgeline.

SNOWPACK: SNOWPACK/AVALANCHE OBS:
Only significant result was an intentionally skier triggered windslab at the top of the bowl. Propagated 40ish feet wide with an average crown of about 4″. Ran 150 feet and was a D1. Windslab failed on lower density storm snow.

Everywhere else we traveled in the bowl we didn’t really find any form of a slab within last weekends storm snow. There were certainly areas to be avoided at all elevations where you likely could have triggered a similarly small windslab.

Dug a pit at 10,700ft. HS 140. Last weekends storm snow was 35cm on a 2cm MFcr. Below this crust was F hard facets that where progressively harder all the way to the ground where they had become 1F hard. The facets just below the MFcr was the layer of concern but needed more of a slab on top to propagate a result. CTH SC, ECTN 20 on this interface.

Shady slopes below treeline have the most concerning structure as the storm snow is sitting on F hard weak facets to the ground. Though we didn’t come across a slope where last weekends storm snow had formed a slab, yet. Unless recent winds had cross loaded the slope. Near the trailhead there had been several storm slabs that failed naturally and where all D1 in size. These storm slabs where shallow and appeared to fail within the storm snow and not on the old snow interface.

UPLOADS:

IMG_0213

Mountain Weather February 25, 2015

CB Avalanche Center February 25, 2015Weather

Date: 02/25/2015

Unsettled northwest flow is developing over Colorado. A few pulses of moisture through the rest of the work week will bring the chance for light snow each day and increased wind speeds. We are too far south and west to catch major accumulations, but a larger storm is brewing for the weekend, which has some similar traits as last weekend’s storm.

Today

High Temperature: 20
Wind Speed: 15-25, G35
Wind Direction: NW
Sky Cover: Mostly Cloudy
Snow: 0-3″

Tonight

Low Temperature: 5
Wind Speed: 10-20
Wind Direction: NW
Sky Cover: Mostly Cloudy
Snow: 0-2″

Tomorrow

High Temperature: 15
Wind Speed: 5-15 mph
Wind Direction: W, NW
Sky Cover: Mostly Cloudy
Snow: 0-2″

Mountain Weather February 25, 2015

CB Avalanche Center February 25, 2015Weather

Date: 02/25/2015

Today

High Temperature: 20
Wind Speed: 15-25, G35
Wind Direction: NW
Sky Cover: Mostly Cloudy
Snow: 0-3″

Tonight

Low Temperature: 5
Wind Speed: 10-20
Wind Direction: NW
Sky Cover: Mostly Cloudy
Snow: 0-2

Tomorrow

High Temperature:
Wind Speed:
Wind Direction:
Sky Cover:
Snow:

Mt. Owen

CB Avalanche Center February 25, 20152014-15 Observations

LOCATION: Kebler Pass Area
DATE OF OBSERVATION: 02/24/2015

SUBJECT: Mt. Owen
ASPECT: North, North West
ELEVATION: 13000 feet

AVALANCHES: Skier triggered storm slab. Broke 1 foot deep propagated 100 feet on steep, shady alpine terrain and ran 1000 feet

WEATHER: clear calm

SNOWPACK: 10-14 inches of new snow, now wind.

UPLOADS:

avy

snow surveys

CB Avalanche Center February 25, 20152014-15 Observations

LOCATION: Crested Butte Area
DATE OF OBSERVATION: 02/24/2015
NAME: ADB

SUBJECT: snow surveys
ASPECT:
ELEVATION:

AVALANCHES: Numerous slides observed on Axtell and Happy Chutes. Most of the slides were soft slab. Damage scale was mostly D1 with some D2. Aspects where activity occurred was from NE to E.

WEATHER: Mostly sunny. calm. Hot

SNOWPACK: Snow survey depths for Red lady Glades: 25 to 35.5 inches for 5 measurements.
Snow Survey depth for Butte: 25 to 42.5 inches for 12 measurements

UPLOADS:

Recent Natural Avalanches along Kebler Pass Road

CB Avalanche Center February 25, 20152014-15 Observations

LOCATION: Kebler Pass Area
DATE OF OBSERVATION: 02/24/2015
NAME: Zach Guy

SUBJECT: Recent Natural Avalanches along Kebler Pass Road
ASPECT: North, North East, East, South
ELEVATION:

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:

Mountain Weather February 24, 2015

CB Avalanche Center February 24, 2015Weather

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.

Today

High Temperature: 25
Wind Speed: 2-12 mph
Wind Direction: NE
Sky Cover: Decreasing clouds
Snow: 0

Tonight

Low Temperature: 15
Wind Speed: 8-18 mph
Wind Direction: NW
Sky Cover: Increasing clouds
Snow: 0-1″

Tomorrow

High Temperature: 22
Wind Speed: 13-23 mph
Wind Direction: NW
Sky Cover: Overcast
Snow: 1-3″

Natural and skier triggered avalanches in Slate River Basin

CB Avalanche Center February 24, 20152014-15 Observations

LOCATION: Crested Butte Area
DATE OF OBSERVATION: 02/23/2015
NAME: Zach Guy

SUBJECT: Natural and skier triggered avalanches in Slate River Basin
ASPECT: North, North East, East, South
ELEVATION: 9,000 -11,400 ft.

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. SS-N-R2-D2-I

Skier triggered soft slab. Schuykill Ridge. N or NE aspect BTL

Natural soft slabs on Peeler Peak. SS-N-R1-D1-I

Skier triggered soft slab. Schuykill Ridge. NE aspect BTL

Mountain Weather February 23, 2015

CB Avalanche Center February 23, 2015Weather

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.