Last nights low temperature  remained above freezing for the most part at valley locations from Valdez to 46 mile.  From tsaina to 46 temps briefly dipped below the freezing mark although the surface of the snow remains unfrozen. Wet loose activity that does occur today will be able to gauge deeper into the snowpack due to a lack of overnight freeze and will likely be confined to low and mid elevations.   Cloudy conditions will likely continue through the day preventing high temps from reaching the levels they did during the last clear cycle.  This will most likely prevent wet loose activity from occurring at upper elevations.

Avoid being exposed to or traveling on slopes steeper than 35° where the surface of the snow is wet or ski penetration is greater than 6 inches due to unfrozen snow.  The hazard for this problem will be on the increase through the weekend as heavy rain on snow becomes likely with high temperatures on the increase region wide.

Light precipitation is expected today with snow lines hovering around 1500′.  This will translate to new snow up high putting pressure on the 4/22 buried surface hoar layer in specific locations and rain down low increasing the likelihood for wet loose activity.

Triggering a persistent slab avalanche up to one foot in depth remains a possibility today.  4-12 inches of snow fell on 4/22 above 3500′ depending upon location.  Below 3500′ temperatures were warmer preventing much in the way of accumulation.

The 4/22 storm was deposited on near surface facets in shaded protected areas at mid-upper elevation and surface hoar up to 1 cm on upper elevation north facing terrain.  On other aspects new snow was deposited on a melt freeze crust.  Expect for the 4/22 buried surface hoar layer to remain reactive on high elevation north facing terrain.  As additional snowfall is expected today through this weekend, this problem will increase in likelihood, depth and sensitivity as the weight of new snow adds stress to a faceted weak layer in our upper snowpack.  Digging snow pits to test the 4/22 interface as well as watching for signs of instability such as shooting cracks and collapsing are good ways to assess this avalanche problem.  The likelihood of this avalanche problem is expected to increase as heavier precipitation arrives on Friday.

In addition to buried surface hoar concerns, north winds developed on 4/23 that redistributed the new snow into sensitive wind slabs.  These slabs were found to still have energy on 4/24 especially were they have were deposited on faceted snow.  Avoid wind loaded slopes in steep upper elevations, as well as cross loaded terrain at mid-upper elevations.

The likelihood of deep slab avalanche activity occurring is slowly increasing, as the overnight freezing line climbs in elevation.  As our snowpack makes the transition from a winter pack to a spring one, deep slab avalanches become increasingly possible.  The most likely trigger to this avalanche problem would include significant wet loose activity and cornice fall.  Avoiding traveling on or exposing yourself to cornices and steep solar aspects where the surface is saturated is highly recommended.  As the season progresses and temperatures continue to rise, so does the possibility for deep slab avalanches to occur.

Weak snow exists at the base of our snowpack.  On 4/15 our area saw the first deep slab activity occur since late February.  This occurred on Meteorite (see avalanche activity section) and was a cornice fall that triggered a series of step down avalanches that eventually stepped down to the ground.  This is a clear indication that large triggers can have an affect on depth hoar.  Increasing temperatures are expected to produce more significant activity later in the season while our snowpack is undergoing a transition from a winter snowpack to a spring one.  

This problem is very difficult to assess due its depth and the fact that signs of instability will likely not be present.  You can stack the odds in your favor by avoiding steep terrain that is undergoing rapid changes such as strong solar and avoiding exposure to large triggers such as cornices.  

Large natural avalanche on Meteorite triggered by cornice fall on 4/15.