Hello all - NWAC recently released a pretty neat tool, and I thought i'd post a letter with some comments about it to get them additional input:
To whom it may concern,
First of all, this is a pretty neat tool and is very useful for experienced back country travelers, thanks for building it! However, it seems dangerous and misleading for the general public, as a more accurate depiction of the back country is shown than NWAC has done analysis or has data/telemetry for. The warning is a bit ironic too - "The avalanche danger forecast is a regional forecast only and is not intended for slope-specific use or interpretation" in that the GIS map is exactly what is asked of users not to use it for; in that slope specific information is presented with only macro level input [this may not be true, as there are no descriptions of how it is generated, so I can only guess]. I am happy to see however, that there is a more detailed disclaimer from some links.
More to the topic at hand - could someone at NWAC write up a summary of the assumptions made for the tool behind the map? i.e. a white paper or something similar describing the logic of how the map is generated with at least the below information?
The following are used to generate the danger color scales [this is how I assume the map is created]:
*Slope aspect, elevation & angle are calculated from USGS 25k topo lines
*NWAC regional danger rose is projected ONLY by slope, elevation and aspect from USGS data
*No other localized data is used to further modify the danger rose in between danger rose & map: i.e. telemetry, recreational skier or ski area reports, etc...
*Historical data is NWAC forecasts only, and actual avalanche events/professionally observations are not accounted for
Thanks!
-Eli
