Dry thunderstorm

A dry thunderstorm is a thunderstorm that produces thunder and lightning, but most or all of its precipitation evaporates before reaching the ground. Dry lightning refers to lightning strikes occurring in this situation. Both are so common in the American West that they are sometimes used interchangeably. The latter term is a technical misnomer since lightning itself is neither wet nor dry. A dry thunderstorm is a thunderstorm that produces thunder and lightning, but most or all of its precipitation evaporates before reaching the ground. Dry lightning refers to lightning strikes occurring in this situation. Both are so common in the American West that they are sometimes used interchangeably. The latter term is a technical misnomer since lightning itself is neither wet nor dry. Dry thunderstorms occur essentially in dry conditions, and their lightning is a major cause of wildfires. Because of that, the National Weather Service, and other agencies around the world, issue forecasts for its likelihood over large areas. Dry thunderstorms generally occur in deserts or places where the lower layers of the atmosphere usually contain little water vapor. Any precipitation that falls from elevated thunderstorms can be entirely evaporated as it falls through the lower dry layers. They are common during the summer months across much of western North America and other arid areas. The shaft of precipitation that can be seen falling from a cloud without reaching the ground is called 'virga'. A thunderstorm does not have to be completely dry to be considered dry; in many areas 0.1 inches (2.5 mm) is the threshold between a 'wet' and 'dry' thunderstorm.