Pat Shingleton: "12/7/'41 and Snow Sheds"
Weather forecasting was in its infancy before the attack on Pearl Harbor on this date in 1941. Weather served as a convenient coding for covert messages that Japan sent to overseas officials leading up to the attack. When Japanese-Soviet relations were broken the message would read, KITA NO KAZE KUMORI or “north wind, cloudy.” If Japanese-British ties were to be cut, the message would read NISHI NO KAZE HARE or “West wind, clear” and if Japan was severing relations with the United States, the message would read HIGASHI NO KAZE AME, or “East wind, rain.” The message would appear at the end of shortwave radio reports alerting officials to destroy all sensitive documents. Also, one of the many hazards included in the construction of the transcontinental railroad was snow. Massive amounts of snow from the Sierras eastward to Sacramento created avalanches that often wiped out newly constructed stretches of rail. In 1887 engineers utilized heavy beams from local timber to construct a sturdy device that not only furthered construction but keep the trains rolling, even today. They're called snow sheds and initially were placed over several miles of exposed track to funnel the sliding snow over the top of the tracks. Today the snow sheds remain a common method for combating the destructive force of avalanches on railroad and highway routes throughout the world. Instead of wood they are constructed with reinforced concrete and steel. On steep slopes, dangerous snow conditions are lessened by installing snow fences that anchor the snow packs.