Today will be the last day of benign weather before a more impactful storm affects our area.  The avalanche hazard today will be similar to what was experienced yesterday.  Shallow instabilities could exist within the recent 6-12 inches of snow that has slowly accumulated since 2/1.  Watch for signs of instability such as shooting cracks, collapsing and recent avalanche activity, that would indicate unstable conditions.  Heavy snowfall is expected to arrive this evening.  The hazard will be higher if the storm arrives earlier that forecasted and we see snowfall rates of more 1 inch/ hour during the day.

The next avalanche forecast will be issued on Wednesday.  Expect for the hazard to increase overnight Monday as up to 2 feet of new snow is expected along with strong south winds by Tuesday morning.

In addition, there is a freezing rain crust that has been identified in the maritime and intermountain zones that extends into upper elevations.  The distribution of this layer has been found to be spotty.  As of 2/2 this layer has been found to have some energy in the maritime zone in stability tests, but is not yet buried by a sufficient slab to be an issue.  This may become a problem layer in the future, in specific areas once additional snowfall arrives.

Surface hoar exists on all aspects above 2500′ in the Intermountain and Continental zones buried 1.5-3 feet deep.  Stability tests have had mixed results as of late, with some areas showing propagation and others being unreactive to not present.  The grain in question is becoming more difficult to locate, has showed signs of rounding (strengthening), laying flat, and being mixed with rounds from beneath.  All signs are pointing towards this layer being dead or dormant.  This layer was found to be 16 inches deep, rounded and unreactive  in the continental zone on 2/4.  

Surface hoar is notorious for surprising users and remaining reactive for long periods of time even after periods of dormancy.  We are leaving this layer on our list for this reason and the potential for large to very large avalanches that would occur should this layer fail. This weak layer will be under increasing stress as moderate to heavy snow arrives Sunday night through Monday.  Once heavy snow arrives the likelihood of triggering an avalanche at this layer will be increasing.  The upcoming storm will give us a good idea if this layer still has the ability to produce avalanches.

Weak snow exists near the base of our snowpack in all three climate zones.  This weak snow will be under increasing pressure as heavy snowfall and strong winds are forecasted Sunday night through Monday.  A step down avalanche occurred during the 1/23-25 storm on Nicks Buttress / ~3500’/ north aspect (see avalanche activity section).  The was the first activity at this layer since 1/6, but does show that weak snow near the base of the snowpack can still produce avalanches.

Faceted snow near the ground has been found to vary significantly from place to place.  In most locations this snow has been found to be rounding (gaining strength) and unreactive in stability tests.  In thin areas of the snowpack these facets are significantly more developed.  On 1/31 a very thin snowpack was found (28-36 inches) ~4000′ on Nicks buttress/North aspect.  Stability tests produced propagation near the ground failing on 6mm depth hoar.  The most likely places to affect weak snow near the ground will be in areas where the snowpack is thin.

If you find it is possible to push a ski pole to the ground in areas you travel.  Assume that a weak faceted snowpack exists in that location, that could act as a trigger point.

Depth hoar from Nicks Buttress ~4000′ North aspect 1/31.