Weather Flashcards
(46 cards)
pressure created by the weight of the air above an area
atmospheric (air) pressure
1 square inch column of air measured from sea level to the top of the atmosphere weighs approximately
14.7 pounds
this tool measures air pressure
barometer
As air cools it becomes more dense and sinks toward the Earth spinning clockwise, this creates
high pressure
as air warms, it becomes less dense and rises above the Earth spinning counterclockwise, this creates
low pressure
Happy weather, clear sunny skies, calm winds, cool dry air
High pressure
Lousy weather, cloudy stormy skies, warm moist air
low pressure
a line connecting two points of equal atmospheric pressure, measured in mb (millibars)
isobars
Tornadoes and Hurricanes are associated with ________ pressure
Low
a large body of air that has relatively uniform temperature and humidity and
air mass
an air mass that originates over land
continental
an air mass that originates over water
maritime
cold air masses tend to approach from
North, Northwest or West
warm air masses tend to approach from
South, Southeast or East
Cooler air masses that are more dense tend to flow toward areas that are less dense, warm and moist
high pressure moves to low pressure
The symbol for a cold front
blue triangles pointed in the direction of the frontal movement
The symbol for a warm front
red humps on a line pointed in the direction of the frontal movement
the symbol for a stationary front
Alternating blue triangles and red humps on a line
the symbol for an occluded front
purple triangles and humps on a line
a cold air mass in replacing a warm air mass. The air behind the front is colder and drier, pressure increases. Showers and thunderstorms form along the leading edge of the front
cold front
A warm air mass is replacing a cold air mass. The air behind the front is warm and moist, the pressure goes down. Widespread continuous precipitation occurs along and ahead of the front
warm front
A boundary between two different air masses neither of which is strong enough to replace the other. Light rain over several days
Stationary Front
Two cold air masses converge on a warm air mass. Occurs when a fast moving cold front overtakes a warm front pushing it up and over cold air. Thundershowers form along the front. After the passage of the front the sky is clear and dry
Occluded Front
A front that approaches from the east or northeast. Cooler maritime air moves in and replaces warmer continental air
Back door cold front
