What is an Avalanche Forecast?
An avalanche forecast is an assessment of the expected risk of avalanches throughout a specific area and time period. This risk assessment is created based on general weather information and snowpack observations, and is designed to help people make decisions on where, what and when to ski, ride, or climb. Avalanche forecasts can be given for a variety of scales, ranging from local resort report and backcountry zones, to mountain range regions and national level.
What Data is Used to Create an Avalanche Forecast?
The most essential data used to create an avalanche forecast comes from studying the snowpack and snowpack trends in an area. Observers will carefully analyze snowpack characteristics such as snow stability, wind slab, temperature trends, and any other relevant conditions present in the snowpack structure. Weather data is used to supplement these observations and is essential in forecasting the development and movement of the snowpack over time.
How Accurate is an Avalanche Forecast?
Avalanche forecasting can be an inexact science, so it’s important to remain aware of potential risks no matter the forecasted conditions. Although avalanche forecasters strive for accuracy and depend greatly on the validity of the data collected, it is difficult to predict the exact conditions present in an area and the development of any processes related to the snowpack.
What Types of Forecasts are Available?
Different organizations create different types of avalanche forecasts, such as daily or weekly overviews that cover the entire area, or more detailed forecasts on a specific day, region or zone. Some resorts offer avalanche reports specific to their area, while other organizations provide large scale overviews of the nation or region. The complexity and breadth of forecast coverage can vary, so it’s important to understand the source of the information and the accuracy of the forecast.
How to Interpret an Avalanche Forecast
Avalanche forecasts are typically created to provide a snapshot of the avalanche risk at a specific point in time, within a designated area. The most common way to organize the forecast is by breaking down the overall potential risk (low, moderate, considerable, high) into its contributing factors (temperature, wind, snow stability, etc.). By understanding how the various factors work together to create the overall risk, one can get a better understanding the current snowpack conditions.
Where to Find Avalanche Forecasts
Avalanche forecasts can be found online or in local mountain shops or ski areas. Many resorts offer in-depth avalanche reports that offer specific hazard warnings and conversely, many websites provide regional forecasts even going so far as to plotting regional maps. Visiting local avalanche centers is also a good way to gather information and first hand insight into the latest condition reports.
People Also Ask
What is an avalanche danger rating?
An avalanche danger rating is the specific hazard level of an area determined by the avalanche forecast. The five standard ratings are low, moderate, considerable, high and extreme.
Who should use an avalanche forecast?
Anyone embarking into a mountain environment that is prone to avalanches should use an avalanche forecast to assess the risk of the area before entry. Hikers, skiers, snowboarders and mountaineers should always check the latest avalanche forecast before entering a mountain zone.
Is an avalanche forecast reliable?
An avalanche forecast should always be taken with caution, as it is difficult to predict the exact conditions in an area. Avalanche forecasts provide good information, but they should not be used as a guarantee of safety.
What is a slab avalanche?
A slab avalanche is an avalanche caused when a cohesive sheet of snow fractures and slides down a slope. They usually occur when new snow falls on a slick frozen layer, creating a fracture in the snowpack.
Why are wind slabs dangerous?
Wind slabs are dangerous because they are a potential source of avalanches. Wind compresses and shrinks snow into a surface crust, and releases it further down the slope in accumulating piles called wind slabs. Those wind slabs can become unstable, and when pressure is applied to them, they can cause an avalanche.
Reading an avalanche forecast is a critical aspect of backcountry safety, as it can provide critical information about the current state of the mountain environment. Understanding the data used to create an avalanche forecast, and how the forecast should be interpreted, can help a person make more informed and safer decisions in the backcountry. Be aware of the potential unreliability of forecasts, and always use precaution when entering a potentially unsafe area.