Weekend Forecast

Issued: Fri, Apr 13, 2018 at 8AM

Expires: Sun, Apr 15, 2018

Above 2,500ft Considerable

1,500 to 2,500ft Considerable

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 danger is generally low on north aspects, and other aspects as well while the snow is frozen in the morning. However, daytime heating will quickly rise the danger to considerable on sunny slopes by afternoon each day.

Problem #1: Wet Avalanches

Location: Steep E-S-W aspects below 5,000ft. Daytime freezing levels are rising up to 4,500ft each day (even higher if the sun comes out). Melting and softening will increase the danger of human-triggered wet slabs and large, dangerous wet sluffs. We’ve have been getting only shallow overnight freezes below 4,500ft, which increases the likelihood of wet slides during the day. Restrict travel on these aspects to the early-morning hours when the snow is still frozen. If the snow softens to ankle-deep or more, it’s time to get off those steep sunny slopes. Keep an eye on our weather stations, watch the temperature trends, and plan accordingly.

Problem #2: Wind Slab

Location: Wind loaded E-S-W aspects 35 degrees and steeper, above 4,500ft. Sensitivity: Stubborn.  North winds over the last two weeks formed recent wind slabs up to 8″ thick on slopes that are lee to the north wind. Keep an eye out for wind loaded slopes where these recent surface slabs may be thick enough to sweep a person down into high-consequence terrain. Bonding is increasing on North aspects, but on southerly aspects these surface slabs will be weakened by solar radiation during the heat of the day.

Fresh soft slab sensitive to human weight. Mt. Ripinsky, Thursday March 29th.

 

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

Friday will be cloudy with some light rain/snow possible (snow levels near 3000ft). Gradual clearing, strong sunshine, and slight cooling is likely this weekend. Temperatures should remain where they’ve been all week: with the freezing level around 2,000ft at night, rising to 4,500ft during the day. Winds look to remain light.

 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
53″ 0″ / 0.00 0″ / 0.20 4,500 light, var 0″/ 0.10 *
Flower Mountain @ treeline
 39″ 0″ / 0.00 0″ / 0.20 4,500 light, var 0″/ 0.10*
Chilkat Pass @ 3,500ft
 17″* 0″ / 0.00 * 0″ / 0.10* 4,000 light, var 0″/ 0.10 *

( *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