Changes to Avalanche Advisory danger rose ahead of winter
Starting this winter, there will be a change to an important component of the avalanche advisories, specifically the danger rose used for each listed avalanche problem.
This change will simplify the avalanche problem message for the reader and better align with the framework the forecaster already uses.
Until now, the danger roses for each avalanche problem have been used to show where an avalanche problem exists at various elevations and aspects in the region, while also applying a danger rating to these sections of the rose.
Starting Saturday June 5, this danger rose will ONLY highlight where the avalanche problem exists (‘area of concern’ in blue) and will NOT apply specific danger ratings to the sections on the rose.
Danger Rose before:
Danger Rose Going Forward:
This change has come about for a few reasons:
- Using danger ratings on an avalanche problem danger rose is not consistent with the current framework snow safety professionals (including NZAA forecasters) are taught to use.
- Assigning danger ratings to each section on an avalanche problem danger rose can be perceived as a highly specific forecast, and it is our belief that at times this may convey more confidence in conditions than a forecaster may have.
- There is concern that in situations where ‘Low’ danger is forecast at lower elevations, but moderate or higher danger is forecast at higher elevations, people may dismiss the avalanche problem prematurely. This situation is known by many as the “Glowing Green Orb”. An example of this from Aoraki/Mt Cook in 2020 can be seen here:
- Simply highlighting the area of concern is a clearer and more appropriate method for providing information on the location of avalanche problems.
- This change aligns the NZAA with many other avalanche centres internationally, including Avalanche Canada, the North-West Avalanche Center (Washington State, USA), Bridger Teton Avalanche Center (Wyoming + Idaho, USA), forecasting centres in Austria, Italy and more.
- Danger ratings will still be used on avalanche advisories.
- There will still be an overall danger rating for each region, as well as danger ratings assigned for each elevation band.
- This change is ONLY for the avalanche problem danger roses.