Decemember 15, 2017

Issued: Fri, Dec 15, 2017 at 12PM

Expires: Mon, Dec 18, 2017

Above 2,500ft Considerable

1,800 to 2,500ft Moderate

Below 1,800ft Low

Degrees of Avalanche Danger ?

1. Low
2. Moderate
3. Considerable
4. High
5. Extreme

Avalanche Danger Rose ?

Avalanche Problems ?

Problem Details

Steady snowfall has deposited 110 inches at Thompson Pass over the past week and a half. The big dump of colder drier snow of 12/6&7 has settled. Onshore southerly winds have redistributed a lot of snow over wind affected terrain. Temperature spikes 12/10&13 have produced moist avalanches that have run to the valley floor.

Recent Avalanche Activity

Moist snow avalanches to size 2.5 observed Monday December 11 to the valley floor at Milepost 40 off Wilbur’s.

Numerous avalanches to size 3 ran to the valley floors across the region Wednesday December 6 and Friday December 8.

Recent Weather

WEATHER FORECAST for NEXT 24 HRS at 3,000 ft:
Temperature Forecast (Min/Max *F):   27/31
Ridgetop Wind Forecast (direction/mph):  NE/10-50
Snowfall (in/water equivalent): 2-9″ /0.88″
WIND & TEMPERATURE
PAST 24 hours
Ferry Terminal Thompson Pass
Average Wind Speed (mph) / Direction   5 /variable 25 /SE shift to NE
Max Wind Gust (mph) / Direction   8 /W  50 /NE
Temperature Min / Max (*F) 33 /37 30/32

Weather Forecast:

Onshore flow continues precipitation. Northerly wind will cool temps and drop freezing level to sea level.

Additional Info & Media

 

SNOW HISTORY: Valdez 12/14 AM Thompson Pass 12/13 AM
24 Hour Snow / Water Equiv. 0”/ 0.89″ 3″ /0.4″
Storm Snow /Water Equiv. [12/10-14]  0″ /3.1″rain 24″ /3.4″
Current Snow Depth 10″ 59″
December Snow / Water Equiv. 33.5″ /12.29″ 107″ / 14.0″
Total Winter Snowfall / Water Equiv. 46.5″ /12.88” 172″ / 19.5″
Snowload in Valdez 45 lbs/sq. ft.

 

SNOWFALL at OTHER STATIONS:
LAST 24 HRS (12/14 AM)/STORM TOTAL (12/10-present)/STORM WATER EQUIV.:
Nicks Valley at 4200 ft (in): 13″ / ~” / ~”
Upper Tsaina at 1750 ft (in): rain” / ” /0.5 last 24 hrs “
Sugarloaf at 550 ft (in): 1+rain”/ ~” / “
SNOW DEPTH & WATER SURVEY (12/2017) Depth Snow Water Equivalent
Milepost 2.5 Valdez  ″  ″
Milepost 18
Milepost 29 Worthington Flats
Milepost 37 Tsaina River bridge
This survey is done the first week of each month.

Weather Quicklinks:

SNOW CLIMATE ZONES:

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

Photo of Thompson Pass

thompson-pass-ski-runs

Interactive Map of Valdez Forecast Areas w/ Many Resource Layers (Trevor Grams)

climate-zones-topoclimate-zones-satellitegoogle-earth1

Run Map of Thompson Pass Area (Sean Wisner) (2MB download)
VAC Run Map Thompson Pass

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.avalancheforecasts.com/

Posted in Continental Forecasts, Intermountain Forecasts, Maritime Forecasts, VAC Forecasts.
Pete Carter

Forecaster: Pete Carter