This is a guest blog post written by Christina Aragon and David Hill from Oregon State University. NWAC supports the work being done by OSU for the Community Snow Observations project. 

We first told the NWAC community about the Community Snow Observations (CSO) project at NSAW 2018 and we are back to update you on the progress we have made since then! For those of you who are new to our work – CSO is a citizen science project aimed at improving estimates of snowpack in mountainous regions by addressing the lack of snow data in our mountains. Since backcountry users are often in remote parts of the landscape where we typically do not have monitoring stations, the snow observations they submit help to fill-in gaps in our observational network. Participation in CSO is easy and all you need is an avalanche probe and a smartphone.

Snoqualmie Pass. Pink markers indicate automated SNOTEL stations and blue markers indicate CSO observations. Note how CSO observations fill-in observational gaps across the landscape.

There are three steps:

1) Find an undisturbed patch of snow in the mountains;

2) Measure the snow depth with your avalanche probe;

3) Submit this observation through the Mountain Hub App or Snow Pilot. Our science team incorporates these observations into a computer model in order to improve our estimates of mountain snow. 

New for this winter – CSO just released an operational snow product at that provides high-resolution real-time snow distribution estimates in numerous regions across the Western US and NH! In the web interface users can view modeled variables such as snow depth, 3-day change in snow depth, snow water equivalent, and how your observations influence the snow snow distribution. Users can also compare the CSO product to other modeled and satellite datasets. Ultimately, these observations help us know where there is good snow for riding, help us better predict hazards such as avalanches and flooding and help us to estimate water resources for downstream communities. 

On the left: Snow depth in Snoqualmie domain. Yellow shading indicates deeper snow and dark purple shading indicates lower snow depths. On the right: 3-day change in snow depth with blue shading showing an increase in depth over the last three days and red shading showing where snow has decreased over the past 3 days.

For the 2021-22 season, we’ve selected two domains in Washington, spanning the Snoqualmie Pass and East Slopes North NWAC forecast zones, to test out and adjust our model. Please submit observations if you are recreating in these areas this winter – the more observations you submit, the better we are able to tune our models. We select our modeling domains primarily based on community participation, so if you would like additional modeling domains for next winter, be sure to submit observations in new areas outside our current modeling domains. Check out the project details and get involved at, Instagram (@communitysnowobs), or Twitter (@communitysnowob)!