Hatcher Pass

The avalanche danger is MODERATE above 3500' for PERSISTENT SLAB avalanches. The danger is LOW elsewhere. In shaded terrain, you may be able to trigger small pockets of wind-drifted snow or loose sluffs. These mostly exist in extreme terrain or along the upper elevation band. While unlikely, avalanches may break wider than expected, failing on weak snow below old wind drifts. 

We had an overnight freeze and skies are expected to be overcast today. Wet avalanche activity is unlikely, but if the sun pokes through the clouds you may see signs of warming on solar slopes. 

Many of today's avalanche problems are small in size. Terrain traps like cliffs, depressions, or exposed rocks increase the consequences of even a small slide. 

SPECIAL ANNOUNCEMENTS: 

Join us in celebrating the end of our forecast season on Saturday 4/18 12-3:30pm in the Independence Mine lot for Gratitude Glizzies (free hot dogs). HPAC is a nonprofit avalanche center, meaning we rely on people like you to do our work, so thank you! More info on our Facebook page. Please consider supporting us reach out Spring Fundraising drive goal. Thanks to a generous donor, all gifts will be matched up to $5k until May 1.

On Tuesday, we received about 3" of snow at .3" of Snow Water Equivalent (SWE), breaking our marathon drought cycle. Prior, Hatcher had only had 1" of SWE in the last 40 days. Last Sunday, we also recorded the the first day in over 40 days since IM snotel had logged a daytime high above freezing. The legacy of March winds remains evident on both polar and solar aspects with stout, old wind slabs which are now shallowly buried. The current story here is the weeks of stable weather that contributed to heavy faceting below these firm layers (see structure photo above). While these shallow, persistent slab avalanches are unlikely, we are not out of the woods yet. Hatcher has an overall lingering, poor structure and even a few decimals of precipitation gave it a nudge--we saw some small, supercifical natural slab avalanches last week that show its potential. Today might be a low probability avalanche day but do not be suprised if we see a persistent slab avalanche cycle still this spring should we get late-season precipitation. 

WET LOOSE:

Wet loose avalanches are unlikely today with cloudy skies expected. Given the time of year, it will not take much to warm snow surfaces on solar aspects--pay attention if clouds begin to break. Watch for signs of instability, like roller balls of wet snow, or a wet snow surface on slopes basking in direct sun. If you notice these signs, be wary of lingering under steep terrain, basking in direct sun, or skiing or riding on southerly slopes late in the day. 

RECENT AVALANCHES:

Hatcher Pass had a small natural avalanche cycle following last week's modest snowfall observed on Wednesday on Thursday. Natural slab avalanches were observed on several northerly aspects at upper elevations as were sluffs on solar aspects. There appeared to be at least one small skier-triggered sluff on the SE side of Eldorado/Skyscraper. 

Last weekend, forecasters in Purchase Creek observed a few new wet-loose avalanches and some more evidence of recent wind-driven instabilities. All of these were small (D1) in size. The most noteworthy avalanche of the last month was a skier-triggered persistent slab on 3/31 on the SE side of Marmot at around 4,300' at 5:20 pm. This avalanche failed within old wind slabs on facets and propagated across the top of a gully feature, and entrained moist surface snow and loose facets near the ground. This made what would have been a shallow and small hard slab avalanche more consequential as it moved slowly into a terrain trap feature.