The direction of wind is explained by reference to the face of a clock The firing line is thought of as the center of a big clockface with 12 o'clock toward the target butts and 6 o'clock to the rear. Wind blowing from the right rear is a 4 o'clock wind (fig. 3-49).

Wind Reading Aids

Wind direction and force can be quickly determined by observing the range flags. Figures 3-50 and 3-51 give examples using the range flag. If no flag is visible, use the following observations as a guide in determining wind velocities:

1. Smoke drifts slightly-less than 2 mph wind

2. Wind can be felt lightly-3 to 5 mph wind

3. Tree leaves move constantly-5 to 8 mph wind

4. Wind raises dust and loose paper-8 to 12 mph wind

5. Small trees sway-12 to 15 mph wind