Identifying Different Snow Grains in a Snowpit

The following video offers some tips and tricks for snow crystal ID. This is something that people often struggle with. THIS VIDEO IS OPTIONAL. The goal of this talk is to help you build a foundation before arriving at the course. After you watch this video, take time to practice crystal ID in the field, whether it’s in the backcountry, at the ski area, or out your front door.

Here is a link to the International Classification for Seasonal Snow on the Ground This link offers further descriptions for improved crystal ID, as well as additional photos.Toggle panel: Restrict this content

Snowpack Metamorphism and the Melt Freeze Process

When the temperature is above 0° C, the snowpack begins to move through a melt-freeze metamorphism. This means that the snowpack is often going through swings of being very strong when it’s frozen and very weak when it’s not frozen each day.

Here are some things to think about.

And here is a deeper dive into wet snow.

It is important to ask different questions when you are dealing with wet snow and wet snow avalanche problems. These questions include:

Did it freeze last night? How thick did it freeze? How is the new snow affecting the old snow? How wet is the snowpack?

You can find an interesting paper about wet snow forecasting here.

CONCLUSION:

Snowpack Metamorphism, Faceting, and Surface Hoar Formation and Metamorphism

How do facets form on the surface of the snow? What drives growth of depth hoar? How does surface hoar form? In the following two videos, Jake will cover a variety of faceting processes including near surface faceting. He will also cover surface hoar growth.

Faceting can also occur on the surface of the snowpack. Faceting that happens at the top of the snowpack, rather than at the bottom of the snowpack is called Near Surface Faceting. There are 3 different near surface faceting processes – Diurnal Recrystallization, Radiation Recrystallization, and Melt Layer Recrystallization.

The following video will cover the faceting process, depth hoar formation, and near surface faceting.

SURFACE HOAR GROWTH AND DEVELOPMENT.

Surface hoar is winter’s dew. It is formed under cold, clear, calm conditions. It is not a problem on the snow surface, but once it is buried, it often forms a weak layer.

Snowpack Metamorphism and the Rounding Process

In the following video series, Jake Hutchinson talks through a variety of snow metamorphism processes. These videos take a deeper dive into snow formation and metamorphism that will help you build a solid foundation of understanding of snowpack development and evolution.

ROUNDING is a metamorphic process that can happen within the snowpack. Rounding occurs when there is a small temperature gradient in the snowpack. Rounding is a strengthening process.

Winter Backcountry Route Planning Using Online Resources

Successful backcountry travel means time spent studying routes before heading out into the field. The more time you spend studying the terrain you might travel through, the better you can anticipate decision-making points, places you might want to stop to evaluate the snowpack, and areas that might hold higher quality snow.

The following video offers a comprehensive look into using Google Earth and CalTopo for route planning.

Keep in mind, online mapping tools are a great resource. The slope angle shading is just an estimate of slope angle. It is essential to take measurements and assess terrain in the field. Do not rely solely on technology or the slope angle shading on these tools.

Here’s an article about tour planning, written by AAI Instructor, Sarah Carpenter

Building a System for Touring with the AAI Backcountry Checklist and Systematic Communication

How do we use the avalanche hazard forecast, current avalanche problems, and current snow and weather observations to put a plan together?  The AAI Backcountry Checklist offers a systematic approach to a tour day. It can help us plan and execute an appropriate tour for the day.

We built this checklist because most of us do most of these things most of the time. The goal of the checklist is to help all of us do all of these things all of the time.