Section 1. Preparation and Siting
1-4
Situations to avoid include:
• large industrial heat sources
• rooftops
• steep slopes
• sheltered hollows
• high vegetation
• shaded areas
• swamps
• areas where snow drifts occur
• low places holding standing water after rains
eight of tree
ogan Uta
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FIGURE 1.3-1. Effect of Structure on Wind Flow
1.4 Determining True North for Wind Vane Orientation
Magnetic declination, or other methods to find True North, should be determined
prior to installing the weather station. True North is usually found by reading a
magnetic compass and applying the correction for magnetic declination*; where
magnetic declination is the number of degrees between True North and Magnetic
North. Magnetic declination for a specific site can be obtained from a USFA map,
local airport, or through a computer service offered by the USFS called GEOMAG