Wind atmosphere based upon how far clouds move from one image to the next. Wind engineering describes the study of the effects of the wind on the built environment, including buildings, bridges and other man-made objects. Historically, the Beaufort wind force scale (created by Beaufort) provides an empirical description of wind speed based on observed sea conditions. Originally it was a 13-level scale, but during the 1940s, the scale was expanded to 17 levels. There are general terms that differentiate winds of different average speeds such as a breeze, a gale, a storm, tornado, or a hurricane. Within the Beaufort scale,
Mistral (wind) is blowing. In the Rhône Valley and on the plain of la Crau, the regularity and force of the mistral causes the trees to grow leaning to the south. Once the forest has been razed by fire, the strong wind makes it difficult for new trees to grow. The farmers of the Rhône Valley have long planted rows of cypress trees to shelter their crops from the dry force of the mistral. The mistral can also have beneficial effects—the moving air can save crops from the spring frost, which can last until the end of April. As summer visitors to