Foehn wind matter of minutes. Central Europe enjoys a warmer climate due to the Föhn, as moist winds off the Mediterranean Sea blow over the Alps. In some regions, föhn winds are associated with causing "circulatory problems", headaches, or similar ailments. Researchers have found, however, the foehn wind's warm temperature to be beneficial to humans in most situations, and have theorised that the reported negative effects may be a result of secondary factors, such as changes in the electrical field or in the ion state of the atmosphere, the wind's relatively low humidity, or the generally unpleasant sensation of being in an
Weather window than 72 hours can be defined as weather-limited operations. These operations can be planned independently of statistical data and based only on weather forecasts. For weather-limited operations, critical factors such as forces, movements and acceleration shall be calculated in a rather worse weather condition (design criterion) than the weather in which it is planned to perform the operation (operational criterion). This is due to the unreliability of weather forecasts. The longer the planned operation lasts, the greater the difference between the operational criterion and the design criterion. The relationship between the operational criterion and the design criterion is defined as