Monday-Thursday

Issued: Mon, Nov 14, 2016 at 8AM

Expires: Thu, Nov 17, 2016

Early season conditions exist – expect the snow character to change rapidly as you climb elevation. Drier snow in the alpine will behave wildly different from the rain affected layers lower on the mountain. Travel with caution; monitor the snowpack for persistent weak layers, especially at the ground. Read this summary on early season conditions posted on Avalanche Canada.

Learn more by taking the Avalanche 1 Class at PWSC beginning this Saturday.
November 19-20 and December 3-4. Register now! 907.834.1600

Above 2,500ft Moderate

1,800 to 2,500ft Low

Below 1,800ft None

Degrees of Avalanche Danger ?

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

Avalanche Danger Rose ?

Avalanche Problems ?

Problem Details

Expect pockets of windslab in gullies and crossloaded slopes. Due to the shifting wind, all aspects are suspect, with northerly aspects most likely to have the deepest wind slab.

The most recent storm ended Nov.12. It deposited 2.5 inches of water equivalent in our mountains, above 3500′, it all came as snow. Expect storm slabs to be up to 2 feet thick. Investigate how this snow is connected to layers beneath. Is there sugary snow down at the ground? Are you finding collapsing snow or hearing whumphing?

There aren’t many recreationalists out and about yet, so please share your observations to give others a heads up – especially if you run into unstable snow or recent avalanche activity.

Recent Avalanche Activity

dsc_1118

loose snow avalanches on North Odyssey 20161111

A few natural wet loose snow avalanches to size 2 were observed in steep terrain. These most likely were triggered by rain on snow Nov.10-11. See North Odyssey photo. With cooling temps, this problem is no longer a concern.

 

Recent Weather

Overnight cooling dried the surface snow at Thompson Pass. Visibility will decrease by mid-day as a new jag of weather brings 3-5 inches of snow to Thompson Pass. East wind to 20mph shifting south. With the southerly onshore weather, expect temperatures to rise with freezing line near 1800′.

Additional Info & Media

SNOW HISTORY: Valdez 11/14 AM Thompson Pass 11/15  AM
Current Snow Depth 1″ 21″
24 Hour Snow / Water Equiv. 0” /0.14″ 5″ / 0.4″
Storm Snow /Water Equiv. (11/11-12) 2” / 2.1” 17″ / 3″
November Snow / Water Equiv. 2″ / 2.75″ 35″ / 4.7″
Total Winter Snowfall / Water Equiv. ?″ / ?” 58″ / 7.1″
Snowload in Valdez 0
SNOW DEPTH & WATER SURVEY (date) 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:

  • NWS forecast for Northeast Prince William Sound <here>
  • NOAA NWS spot forecast for Thompson Pass <here>
  • Valdez Glacier UAF weather station at 6600 feet <data here> <map here>.
  • Thompson Pass weather <here>.
  • Further weather resources <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).

Photo of Thompson Pass <here>

Run map of some of the forecast area <here>

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 VAC Forecasts.
Sarah Carter

Forecaster: Sarah Carter