APPENDIX A (continued)
When slopes are arranged in a valley system, a combination of slope
winds and temperature differences from valley to plain cause valley winds.
These are generally stronger than slope winds, with velocities up to 11 mph (5
m/sec). Generally, the strongest winds are found in U-shaped valleys that have
high ridges lining them and which open onto a broad plain with a considerable
temperature difference between the plain and the head of the valley. Valleys
oriented north or south have the strongest daytime breezes due to increased
exposure to the sun.