The 142nd and final avalanche advisory for the 2017/2018 season was published on April 22nd. Thank you to all who have supported the avalanche center through volunteer hours, field observations, and financial support.
What Happened to the Danger Rose
The Sierra Avalanche Center has joined a movement among US avalanche centers to discontinue use of the danger rose. Our reasoning ( based on theory and our own experience over the years) is that the North American Avalanche Danger Scale http://www.fsavalanche.org/danger-scale is a tool that paints a broad brushstroke of daily conditions … and that applying the scale to the danger rose is an overly specific, and potentially mis-leading, use of that tool .
Avalanche Problems http://www.fsavalanche.org/avalanche-problem are an extension of the danger scale, and provide nuance and specificity to the days avalanche danger. Avalanche problems are composed of four elements: the kind of expected avalanche, where that avalanche may exist in the terrain, how likely you are to trigger it, and, how big it will be. Because these problems address the aspect and elevation question (where each kind of avalanche is most likely to occur) the danger rose is (arguably) no longer needed. Accordingly, avalanche problems are a very important and powerful planning tool. Not all avalanche problems are made, or act, the same. Many avalanche problems (even within the same danger rating!) require significantly different travel and/or risk management strategies.
This change will improve public safety by improving consistency in our messaging at the operational and national scale. We appreciate your understanding and encourage you to refer to the following videos for more information.