It’s spring! Daytime warming loosens and lubricates the snow increasing avalanche danger. Avoid steep slopes late in the afternoon, especially those being baked in direct sunshine or warmed by cloud cover creating the greenhouse effect.
Friday April 14: VAC Full Moon Spring Fling FUNraiser with Acoustic Avalanche at the Tsaina Lodge Grab a date and come boogie!
Above 2,500ft Moderate
1,800 to 2,500ft Moderate
Below 1,800ft Moderate
Degrees of Avalanche Danger ?
|SUNDAY||MONNDAY||TUESDAY & WEDNESDAY|
Elevation: Below 5000′
Aspect: east in am, south, and west in pm
Terrain: Steep terrain near rocks and vegetation.
Sensitivity: Touchy when warmed.
Likelihood (Human Triggered): Likely
Danger Trend: Increasing quickly each day with warming temperatures, falling at night
Forecaster Confidence: Good
Elevation: Above 2500′
Terrain: Slopes > 35*
Sensitivity: Stubborn on northerlies, Touchy when warmed by sun
Likelihood (Human Triggered): Possible
Size: Small – Large
Danger Trend: Decreasing
Forecaster Confidence: Fair
AVALANCHE PROBLEM SCALE DESCRIPTORS:
Sensitivity: Non-reactive, Stubborn, Responsive, Touchy
Distribution: Isolated, Specific, Widespread
Likelihood: Unlikely, Possible, Likely, Nearly Certain
Size: Small, Large, Very Large (size scale <here>)
Danger Trend: Increasing, Steady, Decreasing
Forecaster Confidence: Good, Fair, Poor
AVALANCHE PROBLEM TOOLBOX <here>
Maritime (Coastal) Specific:
Monitor where surface hoar and near surface facets are being buried by fresh flurries.
The storm that ended April 6 laid down 2-4 inches of water equivalent; 3-4 feet of snow up high on the coastal side with rain below ~3600′. That storm snow is settling and bonding relatively well to old layers. The exception is a few upper elevation areas where buried near surface facets are still reactive. South wind during that storm formed new cornices and some pockets of windslab near and below ridgelines.
The tail end of the storm April 4-6 pushed temperatures above freezing to 4500′ on the north side of the pass and up to 5500′ in the maritime. Daytime green house effect (short wave radiation bouncing between the snow surface and cloud cover) and periods of direct sunshine caused wet loose activity to entrain and step down, releasing slab avalanches to size D3. In really shallow areas, wet loose has scoured directly to the ground.
Persistent slab problems are still a concern in colder, thinner and more continental areas. The structure is very poor and the potential for a storm slab or hard slab to step down to weak basal facets is scary. Continue to monitor this structure as temperatures rise and weaken the firmer, overlaying structure.
Find more photos and observations at the bottom of the page. Sharing your observations creates an informed community that everyone benefits from at some point.
Recent Avalanche Activity
Maritime (Coastal) Specific:
- April 6-8: many wet loose avalanches on south aspects 4500′ and below stepped down and pulled out the last storm slab to old firm surfaces. These large size D3 avalanches ran full path. A few reports of similar activity above 4500′.
- April 2: a scattered few human triggered soft slab avalanches up to D2: failed both within new snow (E-NE) and at new-old snow interface (SW)
- March 31: Many small (D1) loose wet avalanches around the port and in Keystone Canyon.
|WEATHER FORECAST for NEXT 24 HRS at 3,000 ft:|
|Temperature Forecast (Min/Max *F):||25 / 27|
|Ridgetop Wind Forecast (direction/mph):||South / 4-15|
|Snowfall (in/water equivalent):||Trace” / Trace”|
|WIND & TEMPERATURE
PAST 24 hours
|Ferry Terminal||Thompson Pass|
|Average Wind Speed (mph) / Direction||3 / Var||9 / Var|
|Max Wind Gust (mph) / Direction||6 / NNW||11 / SE|
|Temperature Min / Max (*F)||34 / 45||25 / 31|
Weather Forecast: Mostly cloudy greybird today with a possibility of window shopping. Freezing line about 1500′. Flurries with next very little acculumation. Variable light wind with moderate northeast wind picking up Monday.
Additional Info & Media
|SNOW HISTORY:||Valdez 4/9 AM||Thompson Pass 4/9 AM|
|24 Hour Snow / Water Equiv.||0”/0.0″||0″ /0″|
|Storm Snow /Water Equiv. (3/27-4/6)||16.9″ /4.1″||24″ /2.4″|
|Current Snow Depth||37″||45″|
|April Snow / Water Equiv.||~″ /1.82″||9″ / 0.9″|
|Total Winter Snowfall / Water Equiv.||239.8″ /24.47”||328″ / 31.5″|
|Snowload in Valdez||65.0 lbs/sq. ft.|
|SNOWFALL at OTHER STATIONS:
LAST 24 HRS (4/8 AM)/STORM TOTAL (3/27-4/6)/STORM WATER EQUIV.:
|Nicks Valley at 4200 ft (in):||0″ / ~16″ / ?”|
|Upper Tsaina at 1750 ft (in):||0″ / ?” / 1.2+”|
|Sugarloaf at 550 ft (in):||0″/ 20+rain” / 2.8″|
|SNOW DEPTH & WATER SURVEY (4/2/2017)||Depth||Snow Water Equivalent|
|Milepost 2.5 Valdez||41.9″||11.9″|
|Milepost 29 Worthington Flats||62.2″||19.6″|
|Milepost 37 Tsaina River bridge||46.3″||12.5″|
|This survey is done the first week of each month.|
- Northeast Prince William Sound NWS Weather Forecast
- Middleton Island Radar for Valdez area
- GOES Alaska water vapor satellite loop
- NOAA NWS Recreational spot forecast for Thompson Pass
- Thompson Pass MP 25.7 RWIS weather station 2740′ (Mesowest)
- Valdez Marine Ferry Terminal weather station sea level
- Nicks Happy Valley above MP 30 weather station 4200′ (scroll to Nicks Valley)
- Upper Tsaina River Snotel near MP 32 1750′
- Sugarloaf Snotel 551′
- Above Valdez Glacier Cryosphere program weather station 6600′ <map here>
- Valdez Blueberry Weather Plot observations (scroll to bottom: Valdez City)
- More Mountain Weather resources for Alaska
- GFS 16 Day Model for Valdez
- Model Average Meteogram for Valdez
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).
Photo of Thompson Pass
Interactive Map of Valdez Forecast Areas w/ Many Resource Layers (Trevor Grams)
NEWS: Our region is “one of the snowiest places on earth” – Serendipity / Rendezvous snowfall record set in 1963 <here>.
Free smart phone avalanche forecasts at: http://www.