GEOS 220 Lecture Notes - Lecture 9: Occluded Front, Alaska Airlines, Vorticity
Document Summary
Air masses are usually classified by temperature and humidity: Continental polar (cp) and continental arctic (ca) air masses. Air is cold and dry and moves into the u. s as shallow high-pressure area. Can damage crops in texas and florida; may cause great lakes-effect snow; can cause an upper-level subsidence inversion. Mountains can act as a barrier to cold air. Cities east of mountains are often times warmer. Leads to clear skies, little to no rainfall. Transition zones between two air masses of different densities. Extension of front is called a frontal surface or a frontal zone. Stationary (quasi stationary) front has essentially no movement. Drawn as an alternating red and blue line on weather maps. Surface winds tend to blow parallel to front, in opposite different on either side. Zone where cold ,dry polar air replaces warm, moist, unstable subtropical air. Location of fronts determined from pressure tendency and temperature of dew point changes.
