Avalanche Advisory for December 2, 2018

Issued: Sun, Dec 02, 2018 at 7AM

Expires: Mon, Dec 03, 2018

Above 3,500ft Considerable

2,500 to 3,500ft Considerable

Below 2,500ft Moderate

Degrees of Avalanche Danger ?

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

Avalanche Danger Rose ?

Avalanche Problems ?

Problem Details

The avalanche hazard will be increasing to CONSIDERABLE today, through this evening, as more snow accumulates in this storm cycle.

If you are headed into the backcountry, expect dangerous avalanche conditions. Use careful snowpack evaluation, cautious route finding, and conservative decision making.

Most avalanches happen within 24 to 48 hours of the storm, this one is no exception. We are currently in a storm cycle with ripe conditions for avalanche activity. 

It’s early season as far as the snowpack is concerned and we are just beginning to get a handle on the conditions. 

The base is thin, shallow and weak. There are already a few layers of concern, from weak, sugary basal facets, to ice and facet/crust layers, to buried surface hoar. Any large load will not bond well to this set up.  On November 30 we observed whumphing and shooting cracks on buried surface hoar in specific locations. More snow on top of this will just aggravate this avalanche problem.

10-12″ of new snow has accumulated at the Independence Mine Snotel since 11/30 (3″ on 11/30 and 8-9″ on 12/1) and about 8″ at the Marmot snow stake. A few inches of snow is expected today, followed by 10-12″ tonight.

Expects loose dry avalanches and storm snow avalanche problems on steep terrain on all aspects and wind slab avalanche problems at mid to upper elevations, on a variety of aspects as strong winds shifted and transported snow during the storm.

 

November 30 snow pit showing the weak base prior to this storm cycle.

 

 

 

 

 

 

 

 

 

 

 

 

As a special note: Southcentral AK was just rocked by an earthquake, and while the damage could have been much worse, as humans, we don’t need to push our luck with avalanches this weekend. Be safe out there, travel with partners, and be practiced and prepared for avalanche rescue.

If you get out and about, please share your observations with your community HERE.

 

 

Recent Avalanche Activity

Marmot Mountain viewed from Idependence Mine Bowl Parkinglot

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

See full observation HERE

Recent Weather

A Winter Weather Advisory is in effect for Hatcher Pass, link HERE.

NWS Recreational Weather Forecast for Hatcher Pass, December 2:

The Hatcher Pass Mountain Forecast covers the mountains in the
Hatcher Pass Recreation Area.

This forecast is for use in snow safety activities and emergency
management.

                   Today        Tonight

Temp at 1000`      29-34 F      23-27 F

Temp at 3000`      25-29 F      17-21 F

Chance of precip   60%          90%

Precip amount
(above 1000 FT)    0.11 in      0.72 in

Snow amount
(above 1000 FT)    1 in         10-12 in

Snow level         800 ft       1200 ft

Wind 3000` ridges  E 6-15 mph   SE 9-21 mph

Additional Info & Media

HPAC will be issuing intermittent snow and avalanche updates through the end of November and into early December, unless conditions warrant advisories or avalanche warnings. 

 

A magnitude 7.2 earthquake shook Southcentral AK this morning, with the epicenter near Palmer, AK.  Infrastructure damage is still being assessed. 

Natural avalanches and rock slides on King Mountain were observed this morning during the initial quake in Chickaloon, AK.

HPAC will be delayed in providing an update this weekend.

We hope that everyone is safe.

If anyone makes their way to HP today or this weekend, please share your observations HERE. There is a decent chance you may see old avalanche activity that occurred during the quake.

Posted in HPAC Forecasts.
Jed Workman

Forecaster: Jed Workman