SNOWPACK
SNOWPACK is the Swiss snowpack evolution model. This model simulates
snowpack layering and characteristics such as density, temperature,
and crystal type throughout the season using a set of relatively
simple meteorological inputs. This model was developed by scientists
from the Swiss Federal Institute for Snow and Avalanche Research
(Michael Lehning and Perry Bartelt) with help from other scientists,
among them Bob Brown and Ed Adams from Montana State University.
It is currently being used operationally in Switzerland.
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Chris Lundy setting up the data collection site in
Montana's Bridger Range for running SNOWPACK.
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The Forest Service National Avalanche Center worked with SFISAR
and MSU scientists, as well as avalanche workers from Snowbasin
Ski Area (Tom Leonard and Mike Jenkins) and the Utah Avalanche
Center (Ethan Greene), to use and test the model during the 1999/2000
and 2000/2001 seasons. Instrumentation to run the model was installed
at two sites at Utah's Snowbasin Ski Area. A third site was installed
near Bridger Bowl, Montana by Chris Lundy, a graduate student
in the Civil Engineering department at Montana State.
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Chris Lundy
downloading data to use for running SNOWPACK |
Chris Lundy
collecting snow crystal data for comparision with SNOWPACK
model output |
Chris
Lundy and Bob Brown at the data collection site |
Though some instrumentation problems prevented us from collecting
complete data sets, we did collect two seasons of data from our
Montana site and a season of data from one site at Snowbasin.
Chris Lundy analyzed the first season of Montana data for part
of his MS thesis, and presented
his results at ISSW 2000. He also published an article
on this work. His thesis focused on an comparison of the model
output with field data he collected. A sampling of some of his
model output is shown below.
Modeled snowpack densities during the 1999/2000 season
Modeled snowpack temperatures during the 1999/2000 season
Modeled snowpack grain type during the 1999/2000 season
Our analyses highlighted some of the shortcomings of SNOWPACK,
but also demonstrated its promise for simulating the evolution
of the seasonal snowcover. Though it clearly cannot replace field
observations, it does have the potential to supplement those observations
as a tool for the human forecaster. At the 2001 Forest Service
National Avalanche Center meeting, we presented the U.S. avalanche
centers with a proposal to run SNOWPACK from a centralized location
for all of the avalanche centers. Unfortunately, the cost of the
project (about $70,000/year) was too expensive for the cash-strapped
avalanche centers.
There were sizable improvements in the model perfomance between
our two seasons, and the model is undergoing continuing refinements.
At an International Glaciological Society conference on snow and
avalanches in Switzerland in June of 2003, a number of people
were working with the model from many different countries. The
National Avalanche Center will continue to keep the U.S. avalanche
centers informed on the continuing improvements and refinements
to the model.