Issued: Wed, Apr 18, 2018 at 8AM

Expires: Wed, Apr 18, 2018

Above 2,500ft Moderate

1,500 to 2,500ft Moderate

Below 1,500ft Low

Degrees of Avalanche Danger ?

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

Avalanche Danger Rose ?

Avalanche Problems ?

Problem Details

The avalanche danger will be Moderate through the day, but rising to CONSIDERABLE this evening as snowfall rates increase.

Problem #1: Storm Snow

Location: All aspects 28 degrees and steeper, above 2,000ft. New snow piling up Wednesday afternoon combined with south winds will lead to storm snow concerns. The new/old snow interface will be crusty/icy on sun-exposed aspects, and facetted/weak on shady north aspects. Bonding of the new snow to this old surface is expected to be poor. The new snow will be prone to forming soft slabs (up to 60cm thick in wind-loaded areas) that may propagate across slopes given the slick bed surface. Look for signs of wind loading (drifts, rounded wind pillows, cornices, etc), and avoid these areas. If you sense hollow, slabby, or cohesive surface snow it would be a good idea to find safer, less wind-affected terrain to ride. Hand shears, small test slopes, and cautious ski cuts will be good ways to  evaluate and manage this danger in the field.

Problem #2: Loose Snow

Location: All aspects 40 degrees and steeper, above 2,000ft. The new snow is not going to bond well. Sensitive fresh wind slabs will exist on wind-affected slopes, and wind protected areas will be prone to loose-snow sluffs that will build and become more dangerous as they move downhill. These sluffs could move fast in steep terrain.

Recent Avalanche Activity

Isolated natural wet-loose avalanches have been occurring over the last week, in the afternoon hours on steep, rocky South through West aspects. These slides have been mostly size 1-2 so far.

Recent Weather

Light snow will come in Wednesday morning, increasing in intensity through Wed. night as snow levels rise to around 2,000ft. 9-12″ of new snow is likely above this level (much less at the Chilkat Pass). An additional 3-6″ is likely through Friday morning above 2,000ft. South winds will be moderate-strong during the storm.

 Snow Depth [in] Last 24-hr Snow/SWE [in] Last 3-days Snow/SWE [in]  Today’s Freezing Level [ft]  Today’s Winds Next 24-hr Snow/SWE
Mount Ripinsky @ treeline
52″ 0″ / 0.00 0″ / 0.00 2,000 light, var 12″/ 1.00 *
Flower Mountain @ treeline
 37″ 0″ / 0.00 0″ / 0.00 2,000 light, var 9″/ 0.80*
Chilkat Pass @ 3,500ft
 17″* 0″ / 0.00 * 0″ / 0.00* 2,000 light, var 5″/ 0.40 *

( *star means meteorological estimate )

Additional Info & Media

If you get out on the snow, send in your observations!

Posted in Lutak Forecasts.
Erik Stevens

Forecaster: Erik Stevens