Valdez

Forecast as of 02/18/2019 at 18:00 and expires on 02/22/2019

Above 4,000ftNone

2,000 to 4,000ftNone

Below 2,000ftNone

Degrees of Avalanche Danger

Low
Moderate
Considerable
High
Extreme

Avalanche Problems

Problem 1

Storm Snow:

Likelihood:

  • Almost Certain
  • Very Likely
  • Likely
  • Possible
  • Unlikely

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 2

Persistent Slab:

Likelihood:

  • Almost Certain
  • Very Likely
  • Likely
  • Possible
  • Unlikely

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 3

Glide Avalanches:

Likelihood:

  • Almost Certain
  • Very Likely
  • Likely
  • Possible
  • Unlikely

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Avalanche Activity

Reports from Feb 15:   
1st slope on moonlight basin slid naturally, crown was blown in but judging by the chunks in the debris crown was 3′ deep in spots.
Small slide in Gully 2 NW aspect SS-N R1-D1.5 3000′.
Small slide on cracked ice N aspect cross loaded gully feature SS-N-R1-D1 3000′.
Hippie Ridge, South aspect ran 1500′, crown is at 4000′, appears to have stepped down potentially to the PWL.,  300’~ below initial crown. SS-N-R2.5-D2.5.

Feb 12: 2 small skier triggered wind slab avalanches were reported from the north side of Billy Mitchell. 2x SS-AS-D1 6″ crown that ‘propagated fairly wide.’

Please share your field observations including signs of stable snow HERE.

Weather

The most recent NWS rec Forecast can be found HERE:

319 PM AKST Sat Feb 16 2019
The Thompson Pass Mountain Forecast covers the mountains (above
1000 ft) surrounding Keystone Canyon through Thompson Pass to
Worthington Glacier.
                   Tonight      Sun

Temp at 1000`      19 F         32 F

Temp at 3000`      22 F         26 F

Chance of precip   100%         100%

Precip amount
(above 1000 FT)    0.31 in      0.85 in

Snow amount
(above 1000 FT)    3-5 in       7-12 in

Snow level         sea level    sea level

Wind 3000` ridges  E 2-15 mph   E 10-30 mph

Additional Information

SNOWPACK BIG PICTURE: In the top 4′ of the snowpack there is a challenging combination of weak layers and new wind slabs in the Valdez region. Below the Jan 23rd buried surface hoar the snow has good strength and structure. The further interior, the problem layers are more widespread and snowpack is considerably shallower.

Recent snowpack history, from top to bottom:

Feb 7-14: Nearly 0″ new snow and building north winds (70mph NE gusts on Feb 14 at Thompson Pass.) Widespread surface hoar growth up to 6mm. In windy locations, and close to the pass, most of this surface hoar has been knocked down.

Feb 3-6: 0.7″ SWE and 8″ of snow from Valdez to Thompson Pass. 8″ of new snow was recorded at 5500′ on Catcher’s Mitt. Freezing level was sea level throughout this cycle.

Jan 30-Feb 1: Natural avalanche cycle on all aspects above 3000′, up to size D3. Most ran on buried surface hoar.

Jan 28-30: 2″ SWE in Valdez, moderate winds, freezing level 1000′.

Jan 23-25: Multiple days of warm and wet with periods of rain up to 2500′.

Jan 13-22: Mostly clear, cold, and dry with light to moderate north winds. Widespread Surface Hoar growth (up to 15mm) and Near Surface Faceting.

Jan 12-13: 3-10″ of new snow with little wind.

Jan 4-12: was VERY cold and dry: moderate winds and wind chill reaching -50F. Pockets of surface hoar and widespread near surface faceting.

Dec 30-Jan 3: The New Year’s Eve storm brought nearly 2.5″ of SWE to Valdez and almost another 1″ (SWE) on the 2-3rd of January. The rain line was 1200′ during the Jan 2-3 storm, forming a 1-3″ crust locking up all the snow beneath it. These storms accumulated over 3′ above 2000′ near Thompson Pass. Both of these storms had little wind.

Above 4000′ the snowpack averages well over 300cm deep and has good strength and structure (few lemons). Below 4000′, the snowpack is significantly shallower and has old problem layers that are bonding well (rounding) and currently dormant: facet-crust combos and BASEL facets (all the way to sea level). 

If you get out riding, please send in an observation.

Do a rescue practice with your partners. Always carry a beacon, shovel, and probe, and KNOW HOW TO USE THEM. 

Practice good risk management, which means only expose one person at a time to slopes 30 degrees and steeper, make group communication and unanimous decision making a priority, and choose your terrain wisely: eliminating unnecessary exposure and planning out your safe zones and escape routes.

Announcements

There is no current hazard rating, read on for the most recent hazard information…..

CONSIDERABLE at all elevation: nearly 2′ of new snow just fell on top of multiple problems layers in the top 4′ of the snowpack.  After 10+ days of no ‘refresh,’ the new snow will be very tempting; but the conditions demand conservative travel techniques AND/OR the patience to wait until the new snow settles. Be mindful of overhead hazards.

More info is available by clicking FULL FORECAST below. (All three forecast regions have the same info.)

Please share your field observations HERE.