earth and space 2 Flashcards
what is an air mass
large chunk of air that acquires characteristics of location
what is a front
boundary between 2 different air masses
always attached to low pressure, never high
4 types of fronts
cold front
warm front
stationary front
occluded front
changes that occur when a cold front passes through
pressure rises temp drops winds shift to north rain cumulonimbus
changes seen when warm front passes
pressure drops temp increases winds shift to south rain is produced stratiform clouds
changes for stationary front
neither cold nor warm air is advancing
soaking rains produced
nimbostratus clouds
changes with occluded front
cold front catches a warm front
behaves like a cold front
what is a forecast
an educated prediction of the future weather
based on observation of current conditions
what way does our weather system move
west to east
steered by jet stream
pushed by prevailing wind
how do you locate a front
locate low pressure system
look for patterns in temp
identify which way air masses are moving
what is a hurricane
tropical cyclone
area of very low pressure
winds rotate in counter clockwise direction
what do you need for a hurricane to form
needs to be over warm water
high humidity
low wind shear
hurricane origin
atlantic hurricanes begin as storms(tropical waves) off the west coast of africa
pushed by prevailing winds
pick up energy from warm ocean water
characteristics of a hurricane
high wind speed-74mph storm surge very low pressure very large produce heavy rainfall
anatomy of a hurricane
rain bands - where air rises and sinks
eye of hurricane
eye wall
how are hurricanes classified
by their wind speed
how does the shape of the coast effect storm surge
if it is a gentle slope there will be a greater storm surge
what is a thunderstorm
cumulonimbus clouds
must have lightning and thunder
severe/strong storms have -
hail
high wind speeds
tornadoes
what is a frontal thunderstorm
when a cold air mass collided with a warm air mass-cold front
cold air causes the warm air to rise quickly forming cumulonimbus clouds
often strong and can last for several hours
what is an air mass thunderstorm
single storm and no fronts
air parcel rises bc it is warmer than the surrounding air
rises quickly bc upper air is cold
what are the two processes of precipitation
warm cloud- water droplets bump into other droplets enough mass/density to fall to earth
cold cloud/ice process- super cooled water evaporates
deposited onto ice crystals
what is hail
ice particles produced by up draft in severe thunderstorms
the more severe the storm-the larger the hail stone
what are the types of lighting
cloud to cloud-most common
cloud to ground- common
ground to cloud- least common
