chapter 6 (exam 2) Flashcards
What three factors cause air masses to move?
Temperature
density
pressure
What are isobars? What do they tell us?
Lines of equal pressure
source regions
Air masses form over source regions and take up there characteristics
The moisture content is designated by
“m” (maritime, which will be moist)
“c” (continental, which will be dry)
The temperature characteristics are designated by
“A” (Arctic)
“P” (Polar)
“T” (Tropical)
“E” (Equatorial)
Arctic and Polar (A and cP)
Originate over northern Canada and the Arctic Circle, influencing the US primarily during the winter.
Very cold and dry; these are the source of cold air outbreaks.
Maritime Polar (mP).
Bring low clouds, fog and precipitation to the Pacific NW
Moisture gets squeezed out because of mountains
Modifies to warm dry air past the mountains
Maritime Tropical (mT)
Develops over Pacific and Caribbean/Gulf of Mexico
Warm and very moist; it is the dominant air mass in the SE US during the summer.
It is the clashing of ——- air that produce much of the weather patterns in martin (and the eastern 2/3 of the country.
mT and cP
What is a front?
A front is a boundary between two different air masses.
Warm Fronts
Warm air advancing towards a retreating cold air mass
Precipitation is generally light
Cold Fronts
Cold air advancing into an area with warmer air, forcing the warm air to rise
The combination of speed and slope cause thunderstorms to develop.
Occluded Fronts
An occluded front develops when a cold front overtakes a warm front and forces both the warm front and warm air to rise
May form strong winds and heavy precipitation.
Stationary Fronts
Neither air mass is advancing, indicating that upper-level winds are parallel to the front.
May produce light precipitation, but likely no severe storms
Mid-Latitude Cyclone
Winds move counter-clockwise, and converge on the low-pressure center.
