Season Final Bulletin, May 13, 2014

Final Spring Bulletin, May 13, 2014     Issued/Updated: 9:00 AM 5/13/14

This is the last bulletin for the 2013-2014 season. It is a quick synopsis of typical spring conditions and how to manage them. Avalanche hazards still remain, so combine the info here and your personal experience to create safe strategies for spring travel in the mountains. Celebrate surviving another winter by soaking up some sun and fun.

Elevations:
  • Alpine – Above 2,000 feet
  • Treeline – 2,000 feet
  • Below treeline – Below 2,000 feet

 

DANGER TREND:  The danger trend will remain steady for the foreseeable future; avalanche danger is less each morning and increases through the day – especially warm, sunny days.

AVALANCHE PROBLEM(S):   As warm, sunny days continue to prevail and summer nears, a variety of new and old avalanche problems can reveal themselves. Wet snow avalanches, deep persistent slab releases and cornice/icefall failure will occur independently or as part of a chain reaction.

icon-wet avalanches

Loose Wet & Wet Slab Avalanches: Wet sluffs continue to initiate around warming rock bands and entrain larger amounts of snow, eventually down to ground. These point releases and/or failing cornices will also trigger larger slab avalanches down to weak layers or the ground. (See avalanche activity below.) Monitor the sun-baked slopes for wet, loose snow and slab sensitivity during these warm days.

 

Problem Specific Travel Advisory - Timing is everything. Plan your outing according to which aspects and elevations are loosing strength. Keep in mind that you don’t want to be stuck in steep terrain when the snow is acting more like water. Use the morning conditions as a timing gauge: the warmer the night-time temperatures, the quicker the snow will degrade that day. Limit exposure to overhead hazards: cornices, couloirs, rock bands etc.

List of Avalanche Problems <here>

GENERAL TRAVEL ADVISORY: 

  • Travel on glaciers requires the gear and skills for crevasse rescue.
  • Snow bridges are sagging and opening up.

AVALANCHE ACTIVITY:  New avalanches to destructive size 2+, continue to initiate in warming rocky areas and on steep north facing faces. While most of these are loose snow releases from solar effect, some slabs have been pulling out naturally on steep, northerly coastal mountain faces around 3,000 ft. The slabs, seen from a distance, have similarities to a human triggered slab from Sunday May 4 on the Pass. These slabs are likely sliding on the Damalanche facet interface, before gouging down to ground in thinner spots. With warm, sunny weather ahead, look out for more of this activity.

  • Avalanche sizing via destructive scale <here>
  • Avalanche size estimation aid <here>.

SNOWPACK DISCUSSION:  With the last warm and sunny period, we have seen that the facets above the Damalanche crust are still a problem in places. Several slides since May 3rd have been large wet slabs running on the crust or just above. Other shallower areas have gouged down directly to the ground-vegetation.

If we get another winter-like storm (not impossible for May), analyze the interface between it and the old surfaces. A storm slab, especially in the high elevations, might just take the first sun to cause activity.

As the snow becomes more isothermal at the upper elevations and until firn snow forms, consider the ability to trigger avalanches down to deep to weak layers or even the ground.

Please CONTRIBUTE to the Snow Observations page <here>.

Photos and observations are welcome and helpful for all to stay in tune with the current conditions. Thanks!

WEATHER: A high pressure ridge will linger over us and provide more sun and warmth through the 3rd week of May. Overnight freezes will lesson and raise in elevation, making for a weaker snowpack. Use links below to follow the up and coming weather.

SNOW & PRECIPITATION HISTORY:
VALDEZ
THOMPSON PASS
24 Hour Snow / Water Equiv.
?” / ?”
0″ / 0.01″
May Snow / Water Equiv.
?” / ?”
0″ / 0.3″
Current Snow Depth
?”
20″
Total Winter Snowfall
?”
335″
(Valdez NWS office has permanently closed=no new data)
MAY 1st SNOW SURVEY:
Location: Depth: Inches of Water: Percent Water:
Valdez 15 5 32%
Milepost 18 20 8 38%
Worthington Glacier 53 20 37%
Milepost 37 31 10 33%

Weather Quicklinks:

  • Valdez Glacier UAF weather station at 6600 feet <data here> <map here>.
  • Thompson Pass weather <here>.
  • Further weather resources <here>
  • Summary of January 13-30 avalanche cycle<here>
  • Season Summary from the beginning of winter to January 8 <here>

SNOW CLIMATE ZONES:

  • Maritime (Coastal) – from the Port of Valdez to Thompson Pass, all waters flowing into Valdez Arm and everything south of Marshall Pass.
  • Inter-mountain (Transitional) – between Thompson Pass and Rendezvous Lodge.
  • Continental (Interior) – the dry north side of the Chugach (north of 46 Mile, including the Tonsina River).

2014 marks the ninth year of public avalanche safety bulletins for the Valdez Chugach mountains October through May

Free smart phone avalanche forecasts at: http://www.avalancheforecasts.com/

Saturday-Tuesday, May 10-May 13, 2014

Saturday-Tuesday, May 10-May 13, 2014     Issued/Updated: 8:00 AM 5/10/14

AVALANCHE DANGER RATING:

SATURDAY:     SUNDAY:     MONDAY & TUESDAY:
Morning: Afternoon:   Morning: Afternoon:   Morning: Afternoon:
Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′
high icon high icon high icon
Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′
high icon high icon high icon

DANGER SCALE details <here> explain the colors and symbols.

Elevations:
  • Alpine – Above 2,000 feet
  • Treeline – 2,000 feet
  • Below treeline – Below 2,000 feet

 

FORECASTER CONFIDENCE: GOOD

DANGER TREND:  The danger trend will remain steady over for the next few days, meaning low each morning and increase each afternoon with warm, sunny days. Temperatures will remain above freezing overnight at the mid elevations.

AVALANCHE PROBLEM(S):  A variety of new and old avalanche problems can reveal themselves during the spring thaw. Wet snow avalanches, deep persistent slab releases and cornice/icefall failure can occur independently or as part of a chain reaction.

icon-wet avalanches

Loose Wet & Wet Slab Avalanches: Solar warming problems have returned. Watch out for wet sluffs off of warming rock bands and failing cornices. Monitor the sun-baked slopes for wet slab sensitivity with these warm days.

Problem Specific Travel Advisory - Limit exposure and travel earlier before the snow gets too soft and saturated with water. Timing is everything.

List of Avalanche Problems <here>

GENERAL TRAVEL ADVISORY: 

  • Travel on glaciers requires the gear and skills for crevasse rescue.
  • Snow bridges are sagging and opening up.

AVALANCHE ACTIVITY:  New avalanches, size 2 to 2+, continue to occur with a scattering of size 3. Most of them are initiating naturally off of solar heated rocks, while one size 3 was human triggered Sunday May 4 on the lower face below Python at about 3,000′. Several of the natural point releases have pulled in adjacent wet slabs, likely sliding on the Damalanche facet interface, before gouging down to ground in thinner spots. With warm, sunny weather ahead, look out for more of this activity.

Human triggered slide on Sun, May 4

20140504_171524[1]L

  • Avalanche sizing via destructive scale <here>
  • Avalanche size estimation aid <here>.

SNOWPACK DISCUSSION:  With the last warm and sunny period, we have seen that the facets above the Damalanche crust can promote a problem. Many slides have used the heavy, wet snow above this weak layer to pull in more snow via wet slabs to create larger events. Other shallower areas have directly gouged down to the depth hoar at the ground-vegetation.  Additionally, consider the increasing temperatures and solar effect as the warm days stick around into next week.

New snow transport could be seen off the summits yesterday, so if you are headed up to the higher peaks, look out for pockets of wind slab near ridge tops. Most old surfaces are hard and won’t play well with new snow util it is given time. On the other hand, north aspects could have preserved dry snow underneath, but look out for near-surface facets that could be buried.

Snow below treeline is melting fast and isothermal. Many aspects at the mid elevations that get a lot of solar radiation are not far behind.

Please CONTRIBUTE to the Snow Observations page <here>.

Photos and observations are welcome and helpful for all to stay in tune with the current conditions. Thanks!

WEATHER: A high pressure ridge will provide more sun and warmth through the weekend. Some clouds may start to settle in Tuesday as the low pressure in the Gulf of Alaska extends out to reach us. Overnight temperatures have returned to above freezing at Thompson Pass.

WEATHER FORECAST for TODAY @ 5,000 ft (RIDGETOP):
Temperature Forecast (deg F): Mid-High 30′s
Ridgetop Wind Forecast (mph): NNE @ 7
Snowfall Expected Next 24 Hrs: 0
SNOW & PRECIPITATION HISTORY:
VALDEZ
THOMPSON PASS
24 Hour Snow / Water Equiv.
?” / ?”
0″ / 0.01″
May Snow / Water Equiv.
?” / ?”
0″ / 0.3″
Current Snow Depth
?”
20″
Total Winter Snowfall
?”
335″
(Valdez NWS office has permanently closed=no new data)
WIND & TEMPERATURE HISTORY (Past 24 Hours) : VALDEZ AIRPORT THOMPSON PASS
Average Wind Speed (mph) / Direction 13 / ENE 33 / NE
Max Wind Gust (mph) 40 43
Temperature Min / Max (deg F) 45 / 64 40 / 49

 

MAY 1st SNOW SURVEY:
Location: Depth: Inches of Water: Percent Water:
Valdez 15 5 32%
Milepost 18 20 8 38%
Worthington Glacier 53 20 37%
Milepost 37 31 10 33%

Weather Quicklinks:

  • Valdez Glacier UAF weather station at 6600 feet <data here> <map here>.
  • Thompson Pass weather <here>.
  • Further weather resources <here>
  • Summary of January 13-30 avalanche cycle<here>
  • Season Summary from the beginning of winter to January 8 <here>

SNOW CLIMATE ZONES:

  • Maritime (Coastal) – from the Port of Valdez to Thompson Pass, all waters flowing into Valdez Arm and everything south of Marshall Pass.
  • Inter-mountain (Transitional) – between Thompson Pass and Rendezvous Lodge.
  • Continental (Interior) – the dry north side of the Chugach (north of 46 Mile, including the Tonsina River).

2014 marks the ninth year of public avalanche safety bulletins for the Valdez Chugach mountains October through May

Free smart phone avalanche forecasts at: http://www.avalancheforecasts.com/

Thursday-Sunday, May 8-May 11, 2014

Thursday-Sunday, May 8-May 11, 2014     Issued/Updated: 7:30 AM 5/8/14

AVALANCHE DANGER RATING:

THURSDAY:     FRIDAY:     SATURDAY & SUNDAY:
Morning: Afternoon:   Morning: Afternoon:   Morning: Afternoon:
Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′
Moderate-150x150 high icon high icon high icon
Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′
Moderate-150x150 Considerable Considerable Considerable

DANGER SCALE details <here> explain the colors and symbols.

Elevations:
  • Alpine – Above 2,000 feet
  • Treeline – 2,000 feet
  • Below treeline – Below 2,000 feet

 

FORECASTER CONFIDENCE: GOOD

DANGER TREND:  The danger is increasing since a reasonable amount of new precipitation has and continues to fall in our forecast area. New rain and/or snow adds weight and stress to an already weakened snowpack after last weeks warm days and little overnight freezing. Snow at the higher elevations will be resting on very firm layers that will not bond immediately. Once the sun shows itself again and/or temperatures rise significantly, be concerned about a series of new avalanches to occur. With the temperatures and precipitation dropping, the daily trend should return to the cycle of lower hazard with nighttime freezing and higher hazard with afternoon warming.

AVALANCHE PROBLEM(S):  A variety of new and old avalanche problems can reveal themselves during the spring thaw. Wet snow avalanches, deep persistent slab releases and cornice/icefall failure can occur independently or as part of a chain reaction.

icon-wet avalanches

Loose Wet & Wet Slab Avalanches: The snow has had a series of warm days to progressively weaken it with limited freezing at night. New rain and/or snow will only add stress despite recent temperatures closer to freezing at night. Solar warming will likely be a problem when the sun shows itself again Thursday or Friday.

Problem Specific Travel Advisory – Be cautious just after a heavy rain-snow event. Let things settle. As days begin to warm again, plan your activity with the daily warming in mind.

List of Avalanche Problems <here>

GENERAL TRAVEL ADVISORY: 

  • Travel on glaciers requires the gear and skills for crevasse rescue.
  • Snow bridges are weakening.

AVALANCHE ACTIVITY:  Many new size 2 to 2+ avalanches have occurred since April 29th with a scattering of size 3. Most of them seem natural, while one size 3 was human triggered Sunday on the lower face below Python at about 3,000′. Most all seem to be starting as point releases, then branch out by pulling wet slabs, sliding on the Damalanche facet interface, before trenching down to ground in thinner spots. These all seem to have happened during the sunny, warm spell.

20140504_171524[1]

  • Avalanche sizing via destructive scale <here>
  • Avalanche size estimation aid <here>.

SNOWPACK DISCUSSION:  With the last warm and sunny period, we have seen that the facets above the Damalanche crust can promote a problem. Many slides have used the heavy, wet snow above this weak layer to pull in more snow via wet slabs to create larger events. Other shallower areas have directly trenched down to the depth hoar at the ground-vegetation.  Keep an eye out for natural activity with added rain and weight to the snowpack. This will only add more lubricant to the weak layers that a slab could slide on. Additionally, consider the increasing temperatures and solar effect as the days warm and skies clear later in the week.

Any new snow that falls at the higher elevations should be inspected to see how it is bonding with the old surfaces below. Most old surfaces are hard and won’t play well with new snow util it is given time. On the other hand, north aspects could have preserved dry snow underneath, but look out for near-surface facets that could be buried.

Snow below treeline is melting fast and isothermal. Many aspects at the mid elevations that get a lot of solar radiation are not far behind.

Please CONTRIBUTE to the Snow Observations page <here>.

Photos and observations are welcome and helpful for all to stay in tune with the current conditions. Thanks!

WEATHER: After a brief break in weather yesterday, overcast skies and rain have pushed back in. It looks like it should start to break Thursday evening, while Friday and onward into the weekend are still looking quite nice and sunny. Overnight temperatures have continued to be closer to freezing at Thompson Pass, but slightly warmer last night. That means rain on the pass and snow line higher up.

WEATHER FORECAST for TODAY @ 5,000 ft (RIDGETOP):
Temperature Forecast (deg F): 36
Ridgetop Wind Forecast (mph): NE @ 10
Snowfall Expected Next 24 Hrs: 0
SNOW & PRECIPITATION HISTORY:
VALDEZ
THOMPSON PASS
24 Hour Snow / Water Equiv.
?” / ?”
0″ / 0.01″
May Snow / Water Equiv.
?” / ?”
0″ / 0.3″
Current Snow Depth
?”
27″
Total Winter Snowfall
?”
335″
(Valdez NWS office has permanently closed=no new data)
WIND & TEMPERATURE HISTORY (Past 24 Hours) : VALDEZ AIRPORT THOMPSON PASS
Average Wind Speed (mph) / Direction 5 / SW 7 / SW
Max Wind Gust (mph) 12 13
Temperature Min / Max (deg F) 39 / 54 31 / 43

 

MAY 1st SNOW SURVEY:
Location: Depth: Inches of Water: Percent Water:
Valdez 15 5 32%
Milepost 18 20 8 38%
Worthington Glacier 53 20 37%
Milepost 37 31 10 33%

Weather Quicklinks:

  • Valdez Glacier UAF weather station at 6600 feet <data here> <map here>.
  • Thompson Pass weather <here>.
  • Further weather resources <here>
  • Summary of January 13-30 avalanche cycle<here>
  • Season Summary from the beginning of winter to January 8 <here>

SNOW CLIMATE ZONES:

  • Maritime (Coastal) – from the Port of Valdez to Thompson Pass, all waters flowing into Valdez Arm and everything south of Marshall Pass.
  • Inter-mountain (Transitional) – between Thompson Pass and Rendezvous Lodge.
  • Continental (Interior) – the dry north side of the Chugach (north of 46 Mile, including the Tonsina River).

2014 marks the ninth year of public avalanche safety bulletins for the Valdez Chugach mountains October through May

Free smart phone avalanche forecasts at: http://www.avalancheforecasts.com/

Wednesday to Saturday, May 7-10, 2014

Wednesday-Saturday, May 7-May 10, 2014     Issued/Updated: 7:30 AM 5/7/14

AVALANCHE DANGER RATING:

WEDNESDAY:     THURSDAY:     FRIDAY & SATURDAY:
Morning: Afternoon:   Morning: Afternoon:   Morning: Afternoon:
Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′
Moderate-150x150 high icon high icon high icon
Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′
Moderate-150x150 Considerable Considerable Considerable

DANGER SCALE details <here> explain the colors and symbols.

Elevations:
  • Alpine – Above 2,000 feet
  • Treeline – 2,000 feet
  • Below treeline – Below 2,000 feet

 

FORECASTER CONFIDENCE: GOOD

DANGER TREND:  The danger is increasing since a reasonable amount of new precipitation has fallen in our forecast area. New rain and/or snow adds weight and stress to an already weakened snowpack after last weeks warm days and little overnight freezing. Snow at the higher elevations will be resting on very firm layers that will not bond immediately. Once the sun shows itself again and/or temperatures rise significantly, be concerned about a series of new avalanches to occur. With the temperatures and precipitation dropping, the daily trend should return to the cycle of lower hazard with nighttime freezing and higher hazard with afternoon warming.

AVALANCHE PROBLEM(S):  A variety of new and old avalanche problems can reveal themselves during the spring thaw. Wet snow avalanches, deep persistent slab releases and cornice/icefall failure can occur independently or as part of a chain reaction.

icon-wet avalanches

Loose Wet & Wet Slab Avalanches: The snow has had a series of warm days to progressively weaken it with limited freezing at night. New rain and/or snow will only add stress despite recent temperatures closer to freezing at night. Solar warming will likely be a problem when the sun shows itself again Thursday or Friday.

Problem Specific Travel Advisory – Be cautious just after a heavy rain-snow event. Let things settle. As days begin to warm again, plan your activity with the daily warming in mind.

List of Avalanche Problems <here>

GENERAL TRAVEL ADVISORY: 

  • Travel on glaciers requires the gear and skills for crevasse rescue.
  • Snow bridges are weakening.

AVALANCHE ACTIVITY:  Many new size 2 to 2+ avalanches have occurred since April 29th with a scattering of size 3. Most of them seem natural, while one size 3 was human triggered Sunday on the lower face below Python at about 3,000′. Most all seem to be starting as point releases, then branch out by pulling wet slabs, sliding on the Damalanche facet interface, before trenching down to ground in thinner spots. These all seem to have happened during the sunny, warm spell.

20140504_171524[1]

  • Avalanche sizing via destructive scale <here>
  • Avalanche size estimation aid <here>.

SNOWPACK DISCUSSION:  With the last warm and sunny period, we have seen that the facets above the Damalanche crust can promote a problem. Many slides have used the heavy, wet snow above this weak layer to pull in more snow via wet slabs to create larger events. Other shallower areas have directly trenched down to the depth hoar at the ground-vegetation.  Keep an eye out for natural activity with added rain and weight to the snowpack. This will only add more lubricant to the weak layers that a slab could slide on. Additionally, consider the increasing temperatures and solar effect as the days warm and skies clear later in the week.

Any new snow that falls at the higher elevations should be inspected to see how it is bonding with the old surfaces below. Most old surfaces are hard and won’t play well with new snow util it is given time. On the other hand, north aspects could have preserved dry snow underneath, but look out for near-surface facets that could be buried.

Snow below treeline is melting fast and isothermal. Many aspects at the mid elevations that get a lot of solar radiation are not far behind.

Please CONTRIBUTE to the Snow Observations page <here>.

Photos and observations are welcome and helpful for all to stay in tune with the current conditions. Thanks!

WEATHER:  While overcast skies and precipitation have settled in, the rain should start to let up Wednesday and clouds start to break Thursday. Hope for a good amount of sun on Friday and Saturday. Overnight temperatures have dipped down to freezing at the elevation of Thompson Pass. That means new snow fell at higher elevations.

WINDS & TEMPERATURES (Past 24 Hours) : VALDEZ THOMPSON PASS
Average Wind Speed / Direction 6 mph / W 12 mph / SSE
Max Wind Gust 13 mph 25 mph
Temperature Min / Max (deg F) 37 / 45 31 / 34
SNOW & PRECIPITATION:
VALDEZ
THOMPSON PASS
24 Hour Snow / Water Equiv.
?” / ?”
trace” / 0.3″
May Snow / Water Equiv.
?” / ?”
trace” / 0.3″
Current Snow Depth
?”
30″
Total Winter Snowfall
?”
335″
(Valdez NWS office has permanently closed=no new data)

 

MAY 1st SNOW SURVEY:
Location: Depth: Inches of Water: Percent Water:
Valdez 15 5 32%
Milepost 18 20 8 38%
Worthington Glacier 53 20 37%
Milepost 37 31 10 33%

Weather Quicklinks:

  • Valdez Glacier UAF weather station at 6600 feet <data here> <map here>.
  • Thompson Pass weather <here>.
  • Further weather resources <here>
  • Summary of January 13-30 avalanche cycle<here>
  • Season Summary from the beginning of winter to January 8 <here>

SNOW CLIMATE ZONES:

  • Maritime (Coastal) – from the Port of Valdez to Thompson Pass, all waters flowing into Valdez Arm and everything south of Marshall Pass.
  • Inter-mountain (Transitional) – between Thompson Pass and Rendezvous Lodge.
  • Continental (Interior) – the dry north side of the Chugach (north of 46 Mile, including the Tonsina River).

2014 marks the ninth year of public avalanche safety bulletins for the Valdez Chugach mountains October through May

Free smart phone avalanche forecasts at: http://www.avalancheforecasts.com/

Tuesday-Friday, May 6-May 9, 2014

Tuesday-Friday, May 6-May 9, 2014     Issued/Updated: 7:00 AM 5/6/14

AVALANCHE DANGER RATING:

TUESDAY:     WEDNESDAY:     THURSDAY & FRIDAY:
Morning: Afternoon:   Morning: Afternoon:   Morning: Afternoon:
Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′
Moderate-150x150 high icon Moderate-150x150 high icon Moderate-150x150 high icon
Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′
Moderate-150x150 Considerable Moderate-150x150 Considerable Moderate-150x150 Considerable

DANGER SCALE details <here>. Memorize this so you know what the colors and numbers are based on.

Elevations:
  • Alpine – Above 2,000 feet
  • Treeline – 2,000 feet
  • Below treeline – Below 2,000 feet

 

FORECASTER CONFIDENCE: FAIR

DANGER TREND:  The danger will increase when a reasonable amount of new precipitation falls or the the temperature rises again after this weather passes. New rain and/or snow will only add weight and stress to an already weakened snowpack after the long stint of warm days with no freezing at night. Snow at the higher elevations will be resting on very firm layers that will take awhile to begin the bonding process. Once the sun shows itself again and/or temperatures rise significantly, be concerned about a series of new avalanches to occur. With the temperatures and precipitation decreasing Wednesday night, the danger should decrease until a warming afternoon could cause some activity.

AVALANCHE PROBLEM(S):  A variety of new and old avalanche problems can reveal themselves during the spring thaw. Wet snow avalanches, deep persistent slab releases and cornice/icefall failure can occur independently or as part of a chain reaction. icon-wet avalanches

Loose Wet & Wet Slab Avalanches: The snow has had a series of warm days to progressively weaken it with limited freezing at night. New rain and/or snow will only add stress to this despite cooler temperatures closer to freezing at night. Solar warming will be a problem when the sun shows itself again.

Problem Specific Travel Advisory – Be causes just after a heavy rain-snow event. Let things settle. As days begin to warm again, plan your activity with the daily warming in mind.

List of Avalanche Problems <here>

GENERAL TRAVEL ADVISORY: 

  • Travel on glaciers requires the gear and skills for crevasse rescue.
  • Snow bridges are weakening.

AVALANCHE ACTIVITY:  Many new size 2 to 2+ avalanches have occurred in the last few days with a scattering of size 3. Most of them seem natural, while one size three was human triggered Sunday on the lower face below Python at about 3,000′. Most all seem to be starting as point releases, then branch out by pulling wet slabs, sliding on the Damalanche facets, before trenching down to ground in thinner spots. These all seem to have happened during the sunny, warm spell.

  • Avalanche sizing via destructive scale <here>
  • Avalanche size estimation aid <here>.

WEATHER:  Overcast skies have settled in, while precipitation should follow, most intensely Tuesday afternoon and into Wednesday or Thursday. Overnight temperatures will dip down closer to freezing the next few nights on the pass. That could mean new snow at higher elevations. The weather will start to break Thursday with a higher chance of sun on Friday.

  • Valdez Glacier UAF weather station <data here> at 6600 feet <map here>.
  • Thompson Pass weather <here>.
  • Further weather resources <here>

SNOWPACK DISCUSSION:  With the last warm and sunny period, we have seen that the facets above the Damalanche crust can be a problem. Many slides have used this weak layer to pull in more snow via wet slabs to create larger events. Other shallower areas have directly trenched down to the depth hoar at the ground.  Keep an eye out for natural activity with added rain and weight to the snowpack. This will only add more lubricant to the weak layers that a slab could slide on. Additionally, consider the increasing temperatures and solar effect as the days warm and skies clear later in the week.

Any new snow that falls at the higher elevations should be inspected to see how it is bonding with the old surfaces below. Most old surfaces are hard and won’t play well with new snow util it is given time. On the other hand, north aspects could have preserved dry snow underneath, but look out for near-surface facets that could be buried.

Snow below treeline is melting fast and isothermal. Many aspects at the mid elevations that get a lot of solar radiation are not far behind.

Please CONTRIBUTE to the Snow Observations page <here>. Photos and observations are welcome and helpful for all to stay in tune with the current conditions. Thanks!

SNOW & PRECIPITATION (updated April 30):

 SEASONAL TOTALS:
VALDEZ
THOMPSON PASS
24 Hour Snow
0″
0″
April Snow
?”
9″
Winter Total
?”
335″
Base
?”
48″
24 Hr Water Equivalent
?”
0″
April Water Equivalent
?”
0.7″
(Valdez NWS office has permanently closed=no new data)

 

May 1st Snow Survey:
Location: Depth: Inches of Water: Percent Water:
Valdez 15 5 32%
Milepost 18 20 8 38%
Worthington Glacier 53 20 37%
Milepost 37 31 10 33%

Summary of January 13-30 avalanche cycle <here>

Season Summary from the beginning of winter to January 8 <here>

SNOW CLIMATE ZONES:

  • Maritime (Coastal) – from the Port of Valdez to Thompson Pass, all waters flowing into Valdez Arm and everything south of Marshall Pass.
  • Inter-mountain (Transitional) – between Thompson Pass and Rendezvous Lodge.
  • Continental (Interior) – the dry north side of the Chugach (north of 46 Mile, including the Tonsina River).

2014 marks the ninth year of public avalanche safety bulletins for the Valdez Chugach mountains October through May

Free smart phone avalanche forecasts at: http://www.avalancheforecasts.com/

Sunday-Wednesday, May 4-May 7, 2014

Sunday-Wednesday, May 4-May 7, 2014     Issued/Updated: 7:30 AM 5/4/14

AVALANCHE DANGER RATING:

SUNDAY:     MONDAY:     TUESDAY & WEDNESDAY:
Morning: Afternoon:   Morning: Afternoon:   Morning: Afternoon:
Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′
Low high icon Low high icon Low Considerable
Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′
Low Moderate-150x150 Low Moderate-150x150 Low Moderate-150x150

DANGER SCALE details <here>. Memorize this so you know what the colors and numbers are based on.

Elevations:
  • Alpine – Above 2,000 feet
  • Treeline – 2,000 feet
  • Below treeline – Below 2,000 feet

 

FORECASTER CONFIDENCE: GOOD

DANGER TREND: The danger is increasing due to very warm spring days ahead. The danger is greater on sun baked slopes during the heat of the day. Consider your options in relation to the slope aspect. The danger decreases with overnight freezing, but forecasted above-freezing temperatures at night may not give the snow a chance to reset. With weather and cooling temperatures possibly arriving Monday night, the danger will decrease Tuesday.

AVALANCHE PROBLEM(S): A variety of new and old avalanche problems can reveal themselves during the spring thaw. Wet snow avalanches, deep persistent slab releases and cornice/icefall failure can occur independently or as part of a chain reaction.

icon-wet avalanches Loose Wet Avalanches: As the snowpack softens throughout these progressively warmer days, expect natural avalanches where the weak snow has lost its ability to stick together. Cold dry snow remains in the shaded upper elevations and should not exhibit this type of problem immediately.

Problem Specific Travel Advisory - Plan your activity with the daily warming in mind. Stay away from steep southeast, south and southwest facing terrain as they become heated by solar radiation.

List of Avalanche Problems <here>

GENERAL TRAVEL ADVISORY: 

  • Travel on glaciers requires the gear and skills for crevasse rescue.
  • Snow bridges are weakening.

AVALANCHE ACTIVITY: Calm, sunny days continue to trigger loose slides off steep, solar aspects at all elevations and produce dirt streaks in the thinner, rocky areas. The avalanche activity from the last few days, is starting to gouge deeper into the isothermal snowpack. This could potentially lead to the triggering of an old weak layer buried below. Releases Wednesday the 30th, on high SW aspects, were nearing size 3. Avalanche activity may slow down with cloudier and cooler weather, but new precipitation may play a part in some concern Tuesday and Wednesday.

  • Avalanche sizing via destructive scale <here>
  • Avalanche size estimation aid <here>.

WEATHER: Sunny, clear weather will stick around through Monday, while temperatures will cool slightly Monday and even more Tuesday as clouds settle in and may bring some rain and/or snow Tuesday afternoon and Wednesday. Overnight temperatures will remain well above freezing Sunday night, but will dip lower, closer to 32 F, at higher elevations Monday night with the weather.

  • Valdez Glacier UAF weather station <data here> at 6600 feet <map here>.
  • Thompson Pass weather <here>.
  • Further weather resources <here>

SNOWPACK DISCUSSION:  While the snowpack feels fairly strong with night-time freezing, recent warm nights at higher elevations can compromise it’s strength. Daily warming could produce larger slab avalanches that are difficult to predict. The Damalanche crust facets buried deeply in the snowpack might become problematic when water percolates down to the crust. Keep an eye out for natural activity, more likely in the afternoon. Additionally, consider whether a smaller slide could possibly step down to the crust and create a much larger incident.

Snow below treeline is melting fast, isothermal and not going to be around long if the warm forecasted weather continues. Many aspects at the mid elevations that get a lot of solar radiation are not far behind.

In contrast, north facing  and wind protected aspects above 4,000 feet are preserving winter snow conditions.

Please CONTRIBUTE to the Snow Observations page <here>. Photos and observations are welcome and helpful for all to stay in tune with the current conditions. Thanks!

SNOW & PRECIPITATION (updated April 30):

 SEASONAL TOTALS:
VALDEZ
THOMPSON PASS
24 Hour Snow
0″
0″
April Snow
?”
9″
Winter Total
?”
335″
Base
?”
48″
24 Hr Water Equivalent
?”
0″
April Water Equivalent
?”
0.7″
(Valdez NWS office has permanently closed=no new data)

 

May 1st Snow Survey:
Location: Depth: Inches of Water: Percent Water:
Valdez 15 5 32%
Milepost 18 20 8 38%
Worthington Glacier 53 20 37%
Milepost 37 31 10 33%

Summary of January 13-30 avalanche cycle <here>

Season Summary from the beginning of winter to January 8 <here>

SNOW CLIMATE ZONES:

  • Maritime (Coastal) – from the Port of Valdez to Thompson Pass, all waters flowing into Valdez Arm and everything south of Marshall Pass.
  • Inter-mountain (Transitional) – between Thompson Pass and Rendezvous Lodge.
  • Continental (Interior) – the dry north side of the Chugach (north of 46 Mile, including the Tonsina River).

2014 marks the ninth year of public avalanche safety bulletins for the Valdez Chugach mountains October through May

Free smart phone avalanche forecasts at: http://www.avalancheforecasts.com/

Friday-Monday, May 2-May 5, 2014

Friday-Monday, May 2-May 5, 2014     Issued/Updated: 7:00 AM 5/2/14

AVALANCHE DANGER RATING:

FRIDAY:     SATURDAY:     SUNDAY & MONDAY:
Morning: Afternoon:   Morning: Afternoon:   Morning: Afternoon:
Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′
Low high icon Low high icon Low high icon
Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′
Low Moderate-150x150 Low Moderate-150x150 Low Moderate-150x150

DANGER SCALE details <here>. Memorize this so you know what the colors and numbers are based on.

Elevations:
  • Alpine – Above 2,000 feet
  • Treeline – 2,000 feet
  • Below treeline – Below 2,000 feet

 

FORECASTER CONFIDENCE: GOOD

DANGER TREND: The danger is steadily increasing due to very warm spring days ahead. The danger is greater on sun baked slopes during the heat of the day. Consider your options in relation to the slope aspect. The danger decreases with overnight freezing, but forecasted above-freezing temperatures at night may not give the snow a chance to reset.

AVALANCHE PROBLEM(S): A variety of new and old avalanche problems can reveal themselves during the spring thaw. Wet snow avalanches, deep persistent slab releases and cornice/icefall failure can occur independently or as part of a chain reaction.

icon-wet avalanches Loose Wet Avalanches: As the snowpack softens throughout these progressively warmer days, expect natural avalanches where the weak snow has lost its ability to stick together. Cold dry snow remains in the shaded upper elevations and should not exhibit this type of problem immediately.

Problem Specific Travel Advisory - Plan your activity with the daily warming in mind. Stay away from steep southeast, south and southwest facing terrain as they become heated by solar radiation.

List of Avalanche Problems <here>

GENERAL TRAVEL ADVISORY: 

  • Travel on glaciers requires the gear and skills for crevasse rescue.
  • Snow bridges are weakening.

AVALANCHE ACTIVITY: Calm, sunny days continue to trigger loose slides off steep, solar aspects at all elevations and produce dirt streaks in the thinner, rocky areas. The avalanche activity from the last few days, is starting to gouge deeper into the isothermal snowpack. This could potentially lead to the triggering of an old weak layer buried below. Releases Wednesday on high SW aspects were nearing size 3. With the series of warm days and nights ahead, they likely will only get larger and more plentiful. Older activity back on the 21st and 22nd reached size 2.5.

  • Avalanche sizing via destructive scale <here>
  • Avalanche size estimation aid <here>.

WEATHER: It looks like sunny, clear weather will stick around into this weekend and even into Monday, with temperatures increasing every day (up to the 50′s on the pass). We could see some weather Monday night. Temperatures will not allow the snow to freeze overnight. With seasonal highs being reached, note the snow’s reactivity each afternoon, amount of water melting into the snowpack and its effect it may have on a deep, persistent weak layers.

  • Valdez Glacier UAF weather station <data here> at 6600 feet <map here>.
  • Thompson Pass weather <here>.
  • Further weather resources <here>

SNOWPACK DISCUSSION:  While the snowpack feels fairly strong with night-time freezing, warmer nights at higher elevations can compromise it’s strength. Daily warming could produce larger slab avalanches that are difficult to predict. The Damalanche crust facets buried deeply in the snowpack might become problematic when water percolates down to the crust. Keep an eye out for natural activity, more likely in the afternoon. Additionally, consider whether a smaller slide could possibly step down to the crust and create a much larger incident.

Snow below treeline is melting fast, isothermal and not going to be around long if the warm forecasted weather continues. Many aspects at the mid elevations that get a lot of solar radiation are not far behind.

In contrast, north facing  and wind protected aspects above 4,000 feet are preserving winter snow conditions where “powder” can be found.

Please CONTRIBUTE to the Snow Observations page <here>. Photos and observations are welcome and helpful for all to stay in tune with the current conditions. Thanks!

SNOW & PRECIPITATION (updated April 30):

 SEASONAL TOTALS:
VALDEZ
THOMPSON PASS
24 Hour Snow
0″
0″
April Snow
?”
9″
Winter Total
?”
335″
Base
?”
48″
24 Hr Water Equivalent
?”
0″
April Water Equivalent
?”
0.7″
(Valdez NWS office has permanently closed=no new data)

 

May 1st Snow Survey:
Location: Depth: Inches of Water: Percent Water:
Valdez 15 5 32%
Milepost 18 20 8 38%
Worthington Glacier 53 20 37%
Milepost 37 31 10 33%

Summary of January 13-30 avalanche cycle <here>

Season Summary from the beginning of winter to January 8 <here>

SNOW CLIMATE ZONES:

  • Maritime (Coastal) – from the Port of Valdez to Thompson Pass, all waters flowing into Valdez Arm and everything south of Marshall Pass.
  • Inter-mountain (Transitional) – between Thompson Pass and Rendezvous Lodge.
  • Continental (Interior) – the dry north side of the Chugach (north of 46 Mile, including the Tonsina River).

2014 marks the ninth year of public avalanche safety bulletins for the Valdez Chugach mountains October through May

Free smart phone avalanche forecasts at: http://www.avalancheforecasts.com/

Thursday-Sunday, May 1-May 4, 2014

Thursday-Sunday, May 1-May 4, 2014     Issued/Updated: 9:00 AM 5/1/14

AVALANCHE DANGER RATING:

THURSDAY:     FRIDAY:     SATURDAY & SUNDAY:
Morning: Afternoon:   Morning: Afternoon:   Morning: Afternoon:
Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′
Low high icon Low high icon  Low high icon
Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′
Low Moderate-150x150 Low Moderate-150x150  Low Moderate-150x150

DANGER SCALE details <here>

Elevations:
  • Above treeline – Above 2,000 feet
  • Treeline – 2,000 feet
  • Below treeline – Below 2,000 feet

 

FORECASTER CONFIDENCE: GOOD

DANGER TREND: The danger is steadily increasing due to very warm spring days ahead. The danger is greater on sun baked slopes during the heat of the day. Consider your options in relation to the slope aspect. The danger decreases with overnight freezing, but forecasted above-freezing temperatures at night may not give the snow a chance to reset.

AVALANCHE PROBLEM(S): A variety of new and old avalanche problems can reveal themselves during the spring thaw. Wet snow avalanches, deep persistent slab releases and cornice/icefall failure can occur independently or as part of a chain reaction.

icon-wet avalanches Loose Wet Avalanches: As the snowpack softens throughout these progressively warmer days, expect natural avalanches where the weak snow has lost its ability to stick together. Cold dry snow remains in the shaded upper elevations and should not exhibit this type of problem immediately.

Problem Specific Travel Advisory - Plan your activity with the daily warming in mind. Stay away from steep southeast, south and southwest facing terrain as they become heated by solar radiation.

List of Avalanche Problems <here>

GENERAL TRAVEL ADVISORY: 

  • Travel on glaciers requires the gear and skills for crevasse rescue.
  • Snow bridges are weakening.

AVALANCHE ACTIVITY: Calm, sunny days continue to trigger loose slides off steep, solar aspects at all elevations and produce dirt streaks in the thinner, rocky areas. The avalanche activity from the last few days, is starting to gouge deeper into the isothermal snowpack. This could potentially lead to the triggering of an old weak layer buried below. Releases Wednesday on high SW aspects were nearing size 3. With the series of warm days and nights ahead, they likely will only get larger. Older activity back on the 21st and 22nd reached size 2.5.

  • Avalanche sizing via destructive scale <here>
  • Avalanche size estimation aid <here>.

WEATHER: It looks like sunny, clear weather will stick around into this weekend and even into Monday, with temperatures increasing every day (up to the 50′s on the pass). Temperatures will not allow the snow to freeze overnight. With seasonal highs being reached, note the snow’s reactivity each afternoon, amount of water melting into the snowpack and its effect it may have on a deep persistent slabs that could get triggered at the old Damalanche crust.

  • Valdez Glacier UAF weather station <data here> at 6600 feet <map here>.
  • Thompson Pass weather <here>.
  • Further weather resources <here>

SNOWPACK DISCUSSION: 

While the snowpack feels fairly strong with night-time freezing, warmer nights at higher elevations can compromise it’s strength. Daily warming could produce larger slab avalanches that are difficult to predict. The Damalanche crust facets buried deeply in the snowpack might become problematic when water percolates down to the crust. Keep an eye out for natural activity, more likely in the afternoon. Additionally, consider whether a smaller slide could possibly step down to the crust and create a much larger incident.

Snow below treeline is melting fast, isothermal and not going to be around long if the warm forecasted weather continues. Many aspects at the mid elevations that get a lot of solar radiation are not far behind.

In contrast, north facing  and wind protected aspects above 4,000 feet are preserving winter snow conditions where “powder” can be found.

Please CONTRIBUTE to the Snow Observations page <here>. Photos and observations are welcome and helpful for all to stay in tune with the current conditions. Thanks!

SNOW & PRECIPITATION (updated April 30):

 SEASONAL TOTALS:
VALDEZ
THOMPSON PASS
24 Hour Snow
0″
0″
April Snow
?”
9″
Winter Total
?”
335″
Base
?”
48″
24 Hr Water Equivalent
?”
0″
April Water Equivalent
?”
0.7″
(Valdez NWS office has permanently closed=no new data)

 

May 1st Snow Survey:
Location: Depth: Inches of Water: Percent Water:
Valdez 15 5 32%
Milepost 18 20 8 38%
Worthington Glacier 53 20 37%
Milepost 37 31 10 33%

Summary of January 13-30 avalanche cycle <here>

Season Summary from the beginning of winter to January 8 <here>

SNOW CLIMATE ZONES:

  • Maritime (Coastal) – from the Port of Valdez to Thompson Pass, all waters flowing into Valdez Arm and everything south of Marshall Pass.
  • Inter-mountain (Transitional) – between Thompson Pass and Rendezvous Lodge.
  • Continental (Interior) – the dry north side of the Chugach (north of 46 Mile, including the Tonsina River).

2014 marks the ninth year of public avalanche safety bulletins for the Valdez Chugach mountains October through May

Free smart phone avalanche forecasts at: http://www.avalancheforecasts.com/

Wednesday-Saturday, April 30-May 3, 2014

Wednesday-Saturday, April 30-May 3, 2014     Issued/Updated: 9:00 AM 4/30/14

AVALANCHE DANGER RATING:

WEDNESDAY:     THURSDAY:     FRIDAY & SATURDAY:
Morning: Afternoon:   Morning: Afternoon:   Morning: Afternoon:
Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′ Above 3,000′
Low high icon  Low high icon  Low high icon
Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′ Below 3,000′
Low Moderate-150x150  Low Moderate-150x150  Low Moderate-150x150

DANGER SCALE details <here>

Elevations:
  • Above treeline – Above 2,000 feet
  • Treeline – 2,000 feet
  • Below treeline – Below 2,000 feet

 

FORECASTER CONFIDENCE: GOOD

DANGER TREND: The danger is steadily increasing due to very warm spring days ahead. The danger is greater on sun baked slopes during the heat of the day. Consider your options in relation to the slope aspect. The danger decreases with overnight freezing.

AVALANCHE PROBLEM(S): A variety of new and old avalanche problems can reveal themselves during the spring thaw. Wet snow avalanches, deep persistent slab releases and cornice/icefall failure can occur independently or as part of a chain reaction.

icon-wet avalanches Loose Wet Avalanches: As the snowpack softens throughout these progressively warmer days, expect natural avalanches where the weak snow has lost its ability to stick together. Cold dry snow remains in the shaded upper elevations and should not exhibit this type of problem immediately.

Problem Specific Travel Advisory - Plan your activity with the daily warming in mind. Stay away from steep southeast, south and southwest facing terrain as they become heated by solar radiation.

List of Avalanche Problems <here>

GENERAL TRAVEL ADVISORY: 

  • Travel on glaciers requires the gear and skills for crevasse rescue.
  • Snow bridges are weakening.

AVALANCHE ACTIVITY: Warm sunny days continue to trigger loose slides off solar aspects at all elevations and produce dirt streaks in the thinner, rocky areas. The avalanche activity from the last two days, the 28th and 29th, is starting to gouge deeper into the isothermal snowpack. This could potentially lead to the triggering of an old weak layer buried below. Older activity back on the 21st and 22nd reached size 2.5.

  • Avalanche sizing via destructive scale <here>
  • Avalanche size estimation aid <here>.

WEATHER: It looks like sunny, clear weather will stick around into this weekend, with temperatures increasing every day. With seasonal highs being reached, note the snow’s reactivity each afternoon, amount of water melting into the snowpack and its effect it may have on a deep persistent slabs that could get triggered at the old Damalanche crust.

  • Valdez Glacier UAF weather station <data here> at 6600 feet <map here>.
  • Thompson Pass weather <here>.
  • Further weather resources <here>

SNOWPACK DISCUSSION: 

While the snowpack feels fairly strong with night-time freezing, spring warming could produce larger slab avalanches. The Damalanche crust facets buried deeply in the snowpack might become problematic when water percolates down to the crust. Keep an eye out for natural activity, more likely in the afternoon. Additionally, consider whether a smaller slide could possibly step down to the crust and create a much larger incident.

Snow below treeline is melting fast, isothermal and not going to be around long if the warm forecasted weather continues. Many aspects at the mid elevations that get a lot of solar radiation are not far behind.

In contrast, north facing  and wind protected aspects above 4,000 feet are preserving winter snow conditions where “powder” can be found.

Please CONTRIBUTE to the Snow Observations page <here>. Photos and observations are welcome and helpful for all to stay in tune with the current conditions. Thanks!

SNOW & PRECIPITATION (updated April 30):

 SEASONAL TOTALS:
VALDEZ
THOMPSON PASS
24 Hour Snow
0″
0″
April Snow
?”
9″
Winter Total
?”
335″
Base
?”
48″
24 Hr Water Equivalent
?”
0″
April Water Equivalent
?”
0.7″
(Valdez NWS office has permanently closed=no new data)

 

May 1st Snow Survey:
Location: Depth: Inches of Water: Percent Water:
Valdez 15 5 32%
Milepost 18 20 8 38%
Worthington Glacier 53 20 37%
Milepost 37 31 10 33%

Summary of January 13-30 avalanche cycle <here>

Season Summary from the beginning of winter to January 8 <here>

SNOW CLIMATE ZONES:

  • Maritime (Coastal) – from the Port of Valdez to Thompson Pass, all waters flowing into Valdez Arm and everything south of Marshall Pass.
  • Inter-mountain (Transitional) – between Thompson Pass and Rendezvous Lodge.
  • Continental (Interior) – the dry north side of the Chugach (north of 46 Mile, including the Tonsina River).

2014 marks the ninth year of public avalanche safety bulletins for the Valdez Chugach mountains October through May

Free smart phone avalanche forecasts at: http://www.avalancheforecasts.com/

Tuesday-Friday, April 29-May 2, 2014

Tuesday-Friday, April 29-May 2, 2014           Issued/Updated: 7:00 AM 4/29/14

AVALANCHE DANGER RATING:

TUESDAY:     WEDNESDAY:     THURSDAY & FRIDAY:
Morning: Afternoon:   Morning: Afternoon:   Morning: Afternoon:
Above 2,000′ Above 2,000′ Above 2,000′ Above 2,000′ Above 2,000′ Above 2,000′
Low Considerable  Low high icon  Low high icon
Below 2,000′ Below 2,000′ Below 2,000′ Below 2,000′ Below 2,000′ Below 2,000′
Low Moderate-150x150  Low Moderate-150x150  Low Moderate-150x150

DANGER SCALE details <here>

Elevations:
  • Above treeline – Above 2,000 feet
  • Treeline – 2,000 feet
  • Below treeline – Below 2,000 feet

 

FORECASTER CONFIDENCE: GOOD

DANGER TREND: The danger is steadily increasing due to very warm spring days ahead. The danger is greater on sun baked slopes during the heat of the day. Consider your options in relation to the slope aspect. The danger decreases with overnight freezing.

AVALANCHE PROBLEM(S): A variety of new and old avalanche problems can reveal themselves during the spring thaw. Wet snow avalanches, deep persistent slab releases and cornice/icefall failure can occur independently or as part of a chain reaction.

icon-wet avalanches Loose Wet Avalanches: As the snowpack softens throughout these progressively warmer days, expect natural avalanches where the weak snow has lost its ability to stick together. Cold dry snow remains in the shaded upper elevations and should not exhibit this type of problem immediately.

Problem Specific Travel Advisory - Plan your activity with the daily warming in mind. Stay away from steep southeast, south and southwest facing terrain as they become heated by solar radiation.

List of Avalanche Problems <here>

GENERAL TRAVEL ADVISORY: 

  • Travel on glaciers requires the gear and skills for crevasse rescue.
  • Snow bridges are weakening.

AVALANCHE ACTIVITY: Warm sunny days are triggering loose slides off solar aspects at all elevations. The activity on the 21st and 22nd reached size 2.5. Avalanches off rocky areas where the snowpack is thinner are producing dirt streaks. The avalanche activity on the 28th is starting to gouge into the deeper snowpack.

  • Avalanche sizing via destructive scale <here>
  • Avalanche size estimation aid <here>.

WEATHER: Clear weather seems like it should dominate this week with temperatures increasing into the weekend. With seasonal highs being reached, note the snow’s reactivity, amount of water melting into the snowpack and its effect it may have on a deep persistent slabs that could get triggered at the old Damalanche crust.

  • Valdez Glacier UAF weather station <data here> at 6600 feet <map here>.
  • Thompson Pass weather <here>.
  • Further weather resources <here>

SNOWPACK DISCUSSION: 

With a series of sunny days with warming temperatures, remember to monitor the Damalanche crust facets buried deeper in the snowpack. There is still concern that this layer could become problematic again after water starts to percolate down to the crust. Keep an eye out for natural activity and increasing sensitivity in the afternoon. Additionally, consider whether a smaller slide could possibly step down to the crust and create a much larger incident.

Snow below treeline is melting fast, isothermal and not going to be around long if the forecasted weather continues for an extended period. Many aspects at the mid elevations that get a lot of solar radiation are not far behind.

In contrast, north facing  and wind protected aspects above 4,000 feet are preserving winter snow conditions where “powder” can be found.

Please CONTRIBUTE to the Snow Observations page <here>. Photos and observations are welcome and helpful for all to stay in tune with the current conditions. Thanks!

SNOW & PRECIPITATION (updated April 29):

 SEASONAL TOTALS:
VALDEZ
THOMPSON PASS
24 Hour Snow
0″
0″
April Snow
?”
9″
Winter Total
?”
335″
Base
?”
52″
24 Hr Water Equivalent
?”
0″
April Water Equivalent
?”
0.7″
(Valdez NWS office has permanently closed=no new data)

 

April 1st Snow Survey:
Location: Depth: Inches of Water: Percent Water:
Valdez 38 14 36%
Milepost 18 45 16 36%
Worthington Glacier 66 24 36%
Milepost 37 51 15 30%

Summary of January 13-30 avalanche cycle <here>

Season Summary from the beginning of winter to January 8 <here>

SNOW CLIMATE ZONES:

  • Maritime (Coastal) – from the Port of Valdez to Thompson Pass, all waters flowing into Valdez Arm and everything south of Marshall Pass.
  • Inter-mountain (Transitional) – between Thompson Pass and Rendezvous Lodge.
  • Continental (Interior) – the dry north side of the Chugach (north of 46 Mile, including the Tonsina River).

2014 marks the ninth year of public avalanche safety bulletins for the Valdez Chugach mountains October through May

Free smart phone avalanche forecasts at: http://www.avalancheforecasts.com/