Comparison of precipitation as measured in gages protected by a modified alter shield, Wyoming shield, and stand of trees

Monthly precipitation recorded at gages exposed to wind, but protected by a Wyoming shield and a modified Alter shield, was compared with precipitation mesasured in small forest openings. During months with snowfall (October-May), the gage protected by a Wyoming shield recorded 42% less precipitation than in the forest stand. Monthly undercatch was statistically significant from September through May; gages measured similar quantities of rainfall in summer. There was 32% undercatch of precipitation in months with snowfall at the gage protected by a modified Alter shield; but this gage also received additional protection from wind by scattered trees at the gage site. Undercatch was statistically significant from August through May. A regression relationship to predict precipitation undercatch in relation to storm windspeed at the gage protected by the Wyoming shield was developed for winter months.