Final SCIENCE weather test (11/14)

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Terms in this set (...)

front
where air masses meet and do not mix
what are the 4 types of fronts?
1. cold front
2. warm front
3. stationary front
4. occluded front
Cold front
cold air mass is replacing warm air mass. cold fronts move quickly and can cause abrupt weather changes as well as rain and snowfall. denser cooler air slides under lighter warmer air and pushes warmer air upwards. happens directly at front.
Warm front
warm air mass is replacing a cold air mass. warm air moves over denser, cooler air. weather may be rainy/foggy for several days. generally happens before front passes.

humid/warm air = showers and light rainfall
dry/warm air = scattered clouds form
Stationary front
a front that stops moving or is moving very slowly. when the fronts meet, neither have the force to move each other. weather consists of rain/snow/fog/clouds. when front starts moving, it either turns warm or cold.
Occluded front
a warm front is trapped by two cold fronts. denser cooler air moves underneath less dense warm air and pushes it upward. weather may be cloudy, rainy & snowy. occluded fronts usually result in storms over an area.
thunderstorms
heavy rain storms accompanied by thunder and lightning
where do thunderstorms form?
within large cumulonimbus clouds or thunderheads
what is needed for a thunderstorm to develop?
1. ample moisture
2. lift (upward moving air)
3. instability of the atmosphere
stages of thunderstorm development
1. cumulus or developing stage
2. mature stage
3. dissipating stage
developing stage
strong updrafts act to develop the storm
mature stage
strong updrafts continue to occur. development of heavy precipitation creates downdrafts
dissipating stage
when updrafts disappear as convection collapses and precipitation diminishes
lightning
natural electrical discharge taking place during a thunderstorm
types of lightning
1. cloud to cloud
2. cloud to ground
thunder
the sound caused by rapidly expanded gases in a lightning discharge (like the sound you hear when you pop a paper bag)
tornadoes
rapidly whirling, funnel-shaped cloud that reaches down from storm cloud to touch Earths surface
what is used to measure tornadoes?
fajita scale
hurricanes
tropical storm that has winds of 119 kilometers per hour or higher
what are hurricanes 3 needs?
1. warm water (evaporation)
2. correct latitude
3. drop in pressure/winds at 74 mph
parts of a hurricane
1. eye
2. eyewall
3. rain bands
eye of a hurricane
center
eyewall of a hurricane
surrounds eye
rain bands of a hurricane
clouds that spin out/make storm bigger
hurricane issues
-storm surge
-rain
-wind
-flooding
before its a hurricane...
...
tropical low
cluster of thunderstorms
tropical depression
more organized, pressure drops, and is assigned a # (1-5)
tropical storm
quite organized, winds 39-73 mph, assigned a name
tropical storm symbol
hurricane symbol
cyclone
swirling center of low air pressure
anti-cyclone
high-pressure centers of dry air
low pressure winds
counterclockwise rotation
inward rotation
rising air at center
high pressure winds
clockwise rotation
outward rotation
sinking air at center