17 terms

air masses and fronts

Air Masses
A large parcel of air that has relatively uniform properties in the horizontal dimension and moves as an entity
characteristics of air masses
must be large, homogeneous, and distinct from surrounding air
formed when atmosphere is calm for a few days
how are air masses classified?
classified according to temperature and moisture characteristics of their source regions.
Continental Arctic (cA)
Extremely cold and very dry, extremely stable, minimal could cover.
Continental Polar (cP)
cold and dry. very stable. minimal could cover.
Maritime Polar (mP)
cold. damp. cloudy. somewhat unstable.
Continental Tropical (cT)
Hot and dry. very unstable.
Maritime Tropical (mT)
warm and humid.
Source regions tend to be...
Physically uniform
Associated with air that is stationary over a long period of time
Warm Fronts
warm air displaces cold air
shallow lift produces stratus clouds
light precipitation
Cold Fronts
cold air displaces warm air
steep uplift causes cumulonimbus clouds and heavy precipitation
Stationary Fronts
Neither air mass encroaches
Warmer Air is displaced aloft
Occluded fronts
When two fronts meet
Cold front closes on a warm front
Dry Lines
Strong humidity boundary
When maritime tropical and continental tropical air masses reside next to eachother
found in the southern great plains
Birth of a cyclone
Characteristics of cyclogenesis
begins along the polar front
low pressure forms
fronts develop
occlusion occurs
storm dissipates
The warm front is always____ of the cold front