Most avalanche forecasting operations choose to maintain a snow study plot. Intermittently, snow must be cleared from the plot to ensure proper recording, despite the available remote control options that exist today.  Since there must be access to the study plot after snowfall, site selection is very important for an operation to consider. Site safety is paramount. Locations where data is acquired have been hit by avalanches and workers have to consider their exposure en route to a study plot just as much as its physical location.  A site that is representative of the forecast area and sheltered from the wind is an additional consideration, while convenient site access is a close third.  According to SWAG, a cleared, level site 10 meters by 7 meters is ideal.  Consider signage or rope barriers to keep unwanted disturbance of the site to a minimum. 

Reference Appendix D in SWAG for more details about proper site selection. This will also be reviewed on course by the instructor team at the plot that will be used for daily observations. Typical recordings made at a manual study plot are detailed below. 

Remote weather stations for winter operations are very helpful and at times may be the only consistent data gathered by an operation. These remote weather stations should be positioned in locations that provide crucial data for the forecast area.  They should also be positioned so that they will hopefully only need minimal maintenance through the winter.  Solar panels and antennas should not be so low as to get buried by snow or so high that they act as a wind sail.  Solar panels need to see several hours of sunlight in mid winter.  

Dispersed snow weather stations throughout the forecast area collecting height of snow, air temperature, and relative humidity can be very useful when determining where hazard may exist.  Unlike weather stations collecting the height of snow, wind weather stations need to be placed in windy areas.  Commonly, they are located along ridgelines or peaks so that they measure wind speeds with as little local terrain influence as possible. Wind stations can also be located low in the terrain to gather targeted data for helicopter landing zones, forecasting loading patterns in specific paths, or commonly used terrain.  Wind weather stations generally collect wind speed and direction, wind gusts, air temperature and relative humidity at a minimum.  

Reference Appendix E in SWAG for more details about combining manual and automated data. This will also be reviewed on course by the instructor team when referencing the stations that will be used for daily observations. Typical recordings made at remote wind and snow study plots are detailed below.

Field observations for winter operations are expected from avalanche workers.  When a forecast area is very large, it is possible that areas are only visited a handful of times each season.  The intermittent data gathered can highlight anomalies not observable from the operation’s normal weather stations and serve to supplement that data foundation .  For this reason, reliable and repeatable field observations are important.  

Field observations are limited in that they are only observed for a small time period.  Areas that are frequently visited by the operation may benefit from more routine field observations.  Difficult to reach locations in the forecast area may go several years between field observations.              

Typical recordings made during a field observation are detailed below