Weather Flashcards
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
instrument that measures wind speed
anemometer
instrument that measures temperature
thermometer
carries instruments to high altitudes to measure pressure, temperature, humidity, and wind speed
weather balloon
helps determine wind direction when reading weather maps
compass rose
measures wind direction as N, S, E, or W
wind vane
this provides the energy for storm systems such as hurricanes
heat
This type of storm forms when an area of low pressure is accompanied by thunderstorms that produce circular winds with wind speeds <38 mph
Tropical depression
This type of storm is a very intense low pressure system forming over tropical oceans that include strong circular winds
Wind speeds ,39-73 mph
Tropical Storm
Tropical depressions, tropical storms and hurricanes all develop in areas of
low pressure
A large storm with high powered circular winds that move in a counter clockwise direction. They form in the Southern Atlantic Ocean, Caribbean, Gulf of Mexico,and Eastern Pacific Ocean
Hurricanes
Conditions needed for a hurricane to form (5)
Location - Ocean
Latitude - 8-20 degrees
Pressure - Low
Temperature - Warm (80 degrees F)
Wind shear - Low
What are the 2 other names for hurricanes in other parts of the world?
tropical cyclone and typhoon
An area of calm weather at the center of the hurricane
eye of the storm
This is an area with the most severe weather in a hurricane
eye wall (area around the eye)
This is the area of the lowest barometric pressure in a hurricane
eye
Hurricanes are classified into how many categories?
5
This is the scale used in the Western Hemisphere
Saffir-Simpson Scale
Hurricane season in the Western Hemisphere is
June 1 - November 1
Hurricanes turn counter clockwise in the Northern hemisphere because of Earth’s rotation. This is known as
The Coriolis Effect
Along with high winds the _______ _______ is usually the most damaging part of a hurricane
storm surge
GOES
Geostationary Operational Environment Satellites
