Orographic precipitation

Seeder And Feeder Clouds

Orographic precipitation is commonly regarded as a distinct type, but this requires careful qualification. Mountains are not especially efficient in causing moisture to be removed from airstreams crossing them, yet because precipitation falls repeatedly in more or less the same locations, the cumulative totals are large. An orographic barrier may produce several effects, depending on its alignment and size. They include 1 forced ascent on a smooth mountain slope, producing adiabatic cooling,...

Zones Of Wave Development And Frontogenesis

Advection Potential Absolute Vorticity

Fronts and associated depressions tend to develop in well-defined areas. The major zones of frontal-wave development are areas that are most frequently baro-clinic as a result of airstream confluence Figure 9.18 . This is the case off East Asia and eastern North America, especially in winter, when there is a sharp temperature gradient between the snow-covered land and warm offshore currents. These zones are referred to as the Pacific polar and Atlantic polar fronts, respectively Figure 9.19 ....