Foehn wind environment with strong and gusty winds. Explanations of the foehn warming and drying effect in popular literature or on the web often single out just one causal mechanism (#1 - Condensation and Precipitation - in the below), but there are in fact four known causes (illustrated in the schematic at top right of this page). These mechanisms often act together, with their contributions varying depending on the size and shape of the mountain barrier and on the meteorological conditions, for example the upstream wind speed, temperature and humidity. 1) Condensation and precipitation: When air is forced upwards over elevated terrain,
Weather spotting Weather spotting Weather spotting is observing weather for the purpose of reporting to a larger group or organization. Examples include National Weather Service (NWS) co-op observers and Skywarn storm spotters. A storm spotter is a specific type of weather spotter. In the U.S., these volunteers are usually trained by the National Weather Service or local Skywarn group, and are given a phone number, internet outlet, or amateur radio frequency to report to if a severe weather event, such as a tornado, severe thunderstorm, or flash flood occurs where the spotter is located. They add ground truth information to remote sensing