Welcome to Snowpack Tracker for the Flathead Avalanche Center (FAC)

This web application provides visualization of weather data, avalanche events, and avalanche hazard ratings for the FAC forecast areas. Graph panels display data at 24-hr resolution, intended as a tool to track seasonal trends in weather and avalanche hazard. All data is updated hourly.

Interactive Tools

Individual stations can be toggled on/off by clicking station symbols in the legend. Each panel's sidebar provides tools for panning, zooming, image saving, and toggling the hover tool and crosshair vertical lines. The date range slider can be used to view any time range within the current season, while the drop-down menu will jump to an Oct. 1 - June 1 view for historical seasons. Default page load is for the previous 30 days. To return to this view, select "Current View" from the drop-down.

Data Sources and Derived Variables

Weather data is sourced from the Synoptic Data API, reported at hourly intervals for all stations. Data plotted for the current day represents derived variables calculated using partial-day observations up to the most recent hour.

Weather stations include:

• Noisy Basin (NOIM8) (SNOTEL)
• Flattop Mtn (FTMM8) (SNOTEL)
• Stahl Pk (STAM8) (SNOTEL)
• Big Mtn Summit (BIGMS) (GNP)
• Hornet (CYFM8) (RAWS)
• Snowslip (SNSLP) (GNP)
• Mt Aeneas (MAEMT) (AVALANCHE)
• Tunnel Ridge Snow (TRSMT) (AVALANCHE)
• Tunnel Ridge Wind (TRWMT) (AVALANCHE)
• Link Mountain (LKMMT) (AVALANCHE)

Precipitation and Snow Depth

24-hr accumulated snow water equivalent (SWE) is derived from hourly SNOTEL snow pillow data. Big Mountain Summit data is sourced from hourly accumulated precipitation gauge data. Snow depth is measured with Judd sonic sensors, where daily depth represents snow depth at the end of the day (midnight local time).

Air Temperature

Displayed as a filled band spanning the 24-hr minimum and maximum air temp.

Wind Speed, Gust, and Direction

Wind speed and gust are displayed as a filled band spanning the 24-hr average speed and maximum gust. Wind direction is plotted as a rotating vector, where the vector indicates compass direction that wind is from. Average direction values are calculated as scaled 24-hr vectors using hourly wind speed and direction data. Wind direction vectors are best viewed for time ranges of 3 months or less.

Avalanche Events

Avalanche event data is sourced from the FAC. Stacked bars represent total recorded events for the 24-hr period, colored by destructive size class ranging D1-D5. Events include all forecast areas.

Hazard Ratings

Forecast avalanche hazard rating data is sourced from the FAC. Hazard ratings use the North American Avalanche Danger Scale, with the following color code:

• Grey: No hazard rating issued
• Green: Low hazard
• Yellow: Moderate hazard
• Orange: Considerable hazard
• Red: High hazard
• Black: Extreme hazard

Each hazard rating panel displays daily ratings for three elevation zones, and an overall rating for the forecast zone. Ratings are posted for the current day within an hour of being submitted by FAC forecasters.

FAQs

Where can I get the raw data?

Visit Synoptic Data to learn more about the Mesonet API services, which provide access to surface weather data across North America and globally. For more information on avalanche events and hazard data, contact the Flathead Avalanche Center.

Can a version of this web application be designed for my forecast center or highway avalanche control operation?

Yes! We have intentionally designed Snowpack Tracker to be transferable to additional regions by leveraging generalized templates and standardized weather data from the Synoptic API. Contact Patrick Wright (pwright@inversionlabs.com) or Tobey Carman (tcarman@inversionlabs.com) for additional information. Visit us at inversionlabs.com.

What software tools do you use?

This web application is written primarily in Python, using Pandas, Bokeh and Flask. Huge thanks to the core developers and open-source community that support these tools!