With the shift to southeast wind, observe where new windslab is forming. Expect the visibility to decrease this afternoon and plan your day accordingly. Cautious route finding and conservative decision making essential. Re-group out of harm’s way.
Above 2,500ft Considerable
1,800 to 2,500ft Moderate
Below 1,800ft Low
Degrees of Avalanche Danger ?
Yesterday northeast wind transported the dry surface snow building fresh windslab on lee features. Observers in Moonlight Basin reported windslab to 8″ deep sensitive to skier trigger. Deeper pockets lee of ridges and gullies could be sensitive to human trigger. As of midnight, a moderate southeast wind has been blowing. Expect to find cross loaded features.
Last snowfall ended Dec. 17 leaving 4-5″ dry snow. The Dec.2-14 storm snow totaled 110″. Current Thompson Pass depth is 5 feet 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
Yesterday’s clear weather allowed for the first visuals since the last storm cycle. Much of the storm avalanche activity was buried and not clearly identifiable. A few pockets of windslab to size 1 were observed primarily above 3000′ lee of ridges and gully walls. Similarly, in Moonlight Basin skiers triggered shallow windslab which propagated across the feature.
Near the port, some stormslab avalanches to size 2 fell out of steep rocky rollovers above 3000′. Some evidence of wet avalanches to size 2 in steep gullies below 3000′ from the Dec.2-14 storm.
|WEATHER FORECAST for NEXT 24 HRS at 3,000 ft:|
|Temperature Forecast (Min/Max *F):||14/32|
|Ridgetop Wind Forecast (direction/mph):||SE/8-30|
|Snowfall (in/water equivalent):||2-10″ /0.84″|
|WIND & TEMPERATURE
PAST 24 hours
|Ferry Terminal||Thompson Pass|
|Average Wind Speed (mph) / Direction||4 /NE||20 /ENE shift to SE|
|Max Wind Gust (mph) / Direction||12 /NNE||24 /SSE|
|Temperature Min / Max (*F)||24 /34||14/18|
Increasing cloud this afternoon with flurries becoming heavy snowfall by evening. Accumulation to 10″. Forecast precip. amounts to 1″ water by Wednesday. Moderate southeast wind increasing this morning 20-30mph as the front moves in.
Additional Info & Media
|SNOW HISTORY:||Valdez 12/18 AM||Thompson Pass 12/18 AM|
|24 Hour Snow / Water Equiv.||1”/ 0.06″||2″ /0.1″|
|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.