Foehn wind 3) Mechanical mixing: When river water passes over rocks, turbulence is generated in the form of rapids, and white water reveals the turbulent mixing of the water with the air above. Similarly, as air passes over mountains, turbulence occurs and the atmosphere is mixed in the vertical. This mixing generally leads to a downward warming and upward moistening of the cross-mountain airflow, and consequently to warmer, drier foehn winds in the valleys downwind. 4) Radiative warming: Dry foehn conditions are responsible for the occurrence of rain shadows in the lee of mountains, where clear, sunny conditions prevail. This often leads
Weather warning [increasing] significantly, but its occurrence, location, and/or timing is still uncertain"" and a warning as ""hazardous weather or hydrologic event [that] is occurring, is imminent, or has a very high probability of occurring"" . Additionally, the NWS breaks down weather warnings and watches based upon the specific type of hazardous weather. These warnings and watches include, but are not limited to, flooding, severe local storms, tropical cyclones, and winter storms. In Canada, governmental weather warnings and watches are issued by the Environment Canada. Non-governmental alerts, not watches or warnings, such as a "rotation detected" or "tornado reported" are issued by