Continued good visibility will make it tempting to test new areas. Cautious route finding and conservative decision making essential. Re-group out of harm’s way. Don’t be tempted to follow other’s tracks if they don’t match your risk tolerance.
Above 2,500ft Considerable
1,800 to 2,500ft Considerable
Below 1,800ft Moderate
Degrees of Avalanche Danger ?
Tuesday’s (12/19) storm included lower density snow and moderate winds – expect windslab on lee features. Wind capable of transporting snow was consistent yesterday afternoon and throughout the night. Pockets lee of ridges and gullies are likely still sensitive to human trigger. Expect to find cross loaded features and larger wind pillows.
We’re expecting the storm snow to become increasingly cohesive.
On steep slopes, we expect loose snow to become easily entrained.
Last snowfall ended Dec. 19 leaving 10-15″ (25-38cm) of dry snow. The Dec.2-14 storm snow totaled 110″. Current Thompson Pass depth is 6+ feet (200cm) with depth increasing with elevation. On Little Girls at about 3500′, Dec.15, an observer reported finding an average snowpack depth of 8-9′ with 4-5′ of that being December’s storm snow.
Recent Avalanche Activity
Broken skies continue today allowing for periods of good visibility. The existing snowpack is still adjusting to the additional load of Tuesday’s (12/19) storm. Steady winds and gusts capable of transporting surface snow continue to cross-load features. At various aspects throughout the advisory area, a few pockets of windslab and loose snow to size D1 (and one size D2) were observed primarily above 3000′ lee of ridges and gully walls, and near rocky outcrops.
Most of the evidence of avalanche activity prior to the 12/19 storm is becoming obscured with the additional new snow and wind transport.
|WEATHER FORECAST for NEXT 24 HRS at 3,000 ft:|
|Temperature Forecast (Min/Max *F):||4/15|
|Ridgetop Wind Forecast (direction/mph):||E-NE/3-25|
|Snowfall (in/water equivalent):||0.1″ /0.01″|
|WIND & TEMPERATURE
PAST 24 hours
|Ferry Terminal||Thompson Pass|
|Average Wind Speed (mph) / Direction||1 /ENE||13 /NE|
|Max Wind Gust (mph) / Direction||8 /N||26 /NE|
|Temperature Min / Max (*F)||19 /25||0/16|
Broken skies. Steady NE wind and gusting in the upper elevations.
Additional Info & Media
|SNOW HISTORY:||Valdez 12/22 AM||Thompson Pass 12/22 AM|
|24 Hour Snow / Water Equiv.||0”/ 0.01″||0″ /0.11″|
|Storm Snow /Water Equiv. [12/10-18]||3.5″ /3.5″snow+rain||46″ /6.4″|
|Current Snow Depth||16″||60″|
|December Snow / Water Equiv.||38″ /13.17″||132″ / 17.6″|
|Total Winter Snowfall / Water Equiv.||51″ /15.42”||197″ / 23.1″|
|Snowload in Valdez||45 lbs/sq. ft.|
|SNOWFALL at OTHER STATIONS:
LAST 24 HRS (12/19 AM)/STORM TOTAL (12/10-18)/STORM WATER EQUIV.:
|Nicks Valley at 4200 ft (in):||0″ / ?” / ?”|
|Upper Tsaina at 1750 ft (in):||0″ / 6″ /1.9″|
|Sugarloaf at 550 ft (in):||0″/ ?” /3.8″|
|SNOW DEPTH & WATER SURVEY (12/2017)||Depth||Snow Water Equivalent|
|Milepost 2.5 Valdez||″||″|
|Milepost 29 Worthington Flats||″||″|
|Milepost 37 Tsaina River bridge||″||″|
|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.