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This occurs when a mountain range forces air to rise.
orographic lifting
localized convective lifting
frontal lifting
convergence
orographic lifting
The most common mechanism of cloud formation is
mixing warm moist air with cold air.
lowering the air temperature to the dew point by adiabatic cooling of rising air.
adding water vapor to the air.
both adding water vapor to the air and mixing warm moist air with cold air.
lowering the air temperature to the dew point by adiabatic cooling of rising air.
You would most likely expect a rain shadow on the
west side of the Andes.
west side of the Coast Range in California.
east side of the Cascade Mountains in the Pacific Northwest.
west side of the Sierra Nevada Mountains.
east side of the Cascade Mountains in the Pacific Northwest.
This type of air will keep rising after an initial upward push.
statically neutral air
none of these types of air rises on its own following an initial lift nor sinks back to its original level
statically stable
statically unstable air
statically unstable air
When the environmental lapse rate exceeds both the dry adiabatic lapse rate and the wet adiabatic lapse rate of a parcel of air, that air parcel contains
absolutely stable air.
conditionally unstable air.
air that cannot reach the lifting condensation level.
absolutely unstable air.
absolutely unstable air.
The lower atmosphere is most likely to have the steepest environmental lapse rate at this time.
mid-day
midnight
sunrise
sunset
mid-day
This is the most important mechanism for stopping the rise of unstable air parcels.
friction
encountering a layer of stable air
reaching the lifting condensation level
entrainment
encountering a layer of stable air
Clouds that are high and are always composed entirely of ice crystals are
nimbus
cirrus
alto
stratus
thunderheads
cirrus
Cumuliform clouds
have very weak vertical velocities within them.
typically have higher water content than stratiform clouds.
form in absolutely stable air conditions.
are typically much wider than they are tall.
typically have higher water content than stratiform clouds.
Collision-coalescence is the predominant cause of precipitation in this region.
mid-latitudes
the Tropics
above the Arctic Circle
subpolar latitudes
the Tropics
The process by which supercooled water droplets freeze onto falling ice crystals is called
riming.
cold-cloud condensation.
Bergeron bonding.
aggregation.
riming.
The collision-coalescence process
is most common at high latitudes.
is most frequent in cold clouds.
explains the formation of snow better than it explains the formation of rain.
is dependent upon the different downward velocities of different-sized droplets.
is dependent upon the different downward velocities of different-sized droplets.
Aggregation
is the first step of the Bergeron process.
is another term for riming.
is facilitated by a thin coating of water on ice crystals.
works best when the cloud temperature is -10 degrees Celsius or colder.
is facilitated by a thin coating of water on ice crystals.
Which of the following cloud constituents would have the highest terminal velocity?
ice crystals
raindrops
hailstones
condensation nuclei
hailstones
The most important principle underlying the Bergeron process is this.
Large drops fall faster than smaller drops.
Aggregation takes place more rapidly than accretion.
The bottom part of the cloud where the process is taking place must be warmer than 0 degrees Celsius.
For a given temperature, the saturation vapor pressure of ice is less than that for supercooled water.
For a given temperature, the saturation vapor pressure of ice is less than that for supercooled water.
Lake-effect snowfall
extends for up to 100 miles south of the lake.
requires that the lake be relatively warm.
requires the presence of stable air.
is most common in late winter.
requires that the lake be relatively warm.
In middle latitudes, rain
is formed by the collision-coalescence process.
is incapable of turning to sleet.
usually begins as snow.
is less common than in high latitudes.
usually begins as snow.
Snow results from all of the following processes, except
deposition.
riming.
coalescence.
aggregation.
coalescence
Precipitation falling through this temperature profile will arrive to the surface as
sleet.
snow.
rain.
freezing rain.
rain.
Which of the following best describes the scale at which cyclones, anticyclones, troughs, and ridges, covering hundreds or thousands of square kilometers, occur?
Synoptic scale
Mesoscale
Microscale
Global scale
Synoptic scale
Meridional flow is characterized by flow that is ________; while zonal flow is characterized by flow that is ________.
west/east; north/south
only east; only north
north/south; west/east
slow; fast
north/south; west/east
The four scales of atmospheric motion from largest to smallest are
micro, meso, synoptic, planetary.
planetary, synoptic, meso, and micro.
planetary, soprano, micro, and meso.
meso, planetary, micro, bass.
planetary, synoptic, meso, and micro.
According to the Hadley cell model,
air sinks at both the equator and the poles.
air sinks at the equator and rises at the poles.
air rises at the equator and sinks at the poles.
air rises at both the equator and the poles.
air rises at the equator and sinks at the poles.
The Hadley Cell was originally envisaged to cover most, if not all of each hemisphere, North and South. What area does it actually cover?
just the Tropics and the Mid-Latitudes
just areas near the equator
just the Mid-latitudes
just the Tropics
just areas near the equator
Areas close to the ITCZ
receive little precipitation.
frequently experience droughts.
receive abundant precipitation.
receive abundant precipitation, mostly as snow.
receive abundant precipitation.
Examine Figure 8-15 in the textbook, which is a sequence of Rossby Waves.
What are the southward bulges in the patterns called?
Ridges
Jet streams
Troughs
Spirals
Troughs
The polar front
is not associated with the polar jet stream.
is a region marked by a sharp change in horizontal temperature.
is a boundary between two regions of cold air.
is a region of small changes in the slope of pressure surfaces.
is a region marked by a sharp change in horizontal temperature.
Winds in the upper atmosphere are
westerly only in the southern hemisphere.
westerly only in the northern hemisphere.
westerly in both the northern and southern hemisphere.
faster in summer than in winter in both the northern and southern hemisphere.
westerly in both the northern and southern hemisphere.
Westerly winds in the upper atmosphere at mid-latitudes in the Northern Hemisphere
are moving perpendicular to 500 mb contours.
are stronger in summer than in winter.
are a result of a pressure gradient that moves air from the poles toward the equator.
are the reason most mid-latitude storms move from west to east.
are the reason most mid-latitude storms move from west to east.
The Ferrel Cell is associated with the
poles.
mid-latitudes.
tropics.
high-latitudes.
mid-latitudes.
What are jet streams?
Bands of high-speed wind found at elevations of 5-9 km
Bands of low-speed wind found at elevations of 9-15 km
Bands of low-speed wind found at elevations of 5-9 km
Bands of high-speed wind found at elevations of 9-15 km
Bands of high-speed wind found at elevations of 9-15 km
In which direction do jet streams generally travel?
east to west
south to north
north to south
west to east
west to east
Where are the two main hemispheric jet streams located?
between 50 and 60 degrees longitude and at about 30 degrees longitude
above 60 degrees latitude and below 30 degrees latitude
between 50 and 60 degrees latitude and at about 30 degrees latitude
above 60 degrees longitude and below 30 degrees longitude
between 50 and 60 degrees latitude and at about 30 degrees latitude
What are Rossby waves?
minor undulations in the Earth's orbital parameters
major undulations in the path of a jet stream
minor undulations in the path of a jet stream
major undulations in Earth's orbital parameters
major undulations in the path of a jet stream
How can the jet stream return to normal zonal flow after Rossby waves build?
through separation of a mass of cold water from the jet stream
through addition of a mass of cold water to the jet stream
through separation of a mass of cold air from the jet stream
through addition of a mass of cold air to the jet stream
through separation of a mass of cold air from the jet stream
The Hadley model of atmospheric circulation assumes
an equal distribution of land and water across the earth.
the earth does not receive any sunlight.
a planet covered entirely by water.
an unequal distribution of land and water across the earth.
a planet covered entirely by water.
The Hadley cell
creates a high-pressure area at the equator.
does not explain upper air movement in the troposphere.
does not account for the formation of trade winds.
originates with strong solar heating at the equator.
originates with strong solar heating at the equator.
The northeast trade winds
are the result of air flowing from the subtropical high to the ITCZ.
span the horse latitudes.
have been the dread of sailors for centuries.
are the product of a strong Coriolis force.
are the result of air flowing from the subtropical high to the ITCZ.
Usually, the pressure gradient force would be strongest at the
950 mb level.
800 mb level.
900 mb level.
700 mb level.
700 mb level.
Which of the following best defines an air mass?
A large body of air with similar temperature and moisture characteristics
A large body of air containing fronts
A large body of air residing over a water mass
A large body of air with uniform temperature and no precipitation
A large body of air with similar temperature and moisture characteristics
[___] air masses originate over water.
Arctic (A)
Polar (P)
Continental (c)
Maritime (m)
Tropical (T)
Maritime (m)
[___] and [___] air masses are cold.
Arctic (A)
Polar (P)
Continental (c)
Maritime (m)
Tropical (T)
Arctic (A) and Polar (P)
[___] and [___] air masses are warm and humid
Tropical (T) and Maritime (m)
[___] and Tropical (T) air masses are warm and dry.
Continental (c)
[___] and [___] air masses originate at high latitudes.
Polar (P) and Arctic (A)
[___] is a term referring to dry air masses.
Continental ©
When a cold air front moves rapidly toward a warm air front, there isn’t time to predict the light and longer-lasting rains that result from the warm air dissipating.
True or False
False
When warm air collides with a cold air front, its slow journey up the slope of the cold air front causes longer rains. Because it moves slowly, its rain is long foretold and long to last.
True or False
True
Rainstorms are generally shorter when a cold air front comes in quickly and collides with a warm air front.
True or False
True
Heavier, intense, long-lasting rainstorms occur when a warm air front encounters a receding cold air front.
True or False
False
It’s hard to apply this proverb to most storm conditions, because storms typically result when fronts are moving at the same speed and in the same direction.
True or False
False
Air-mass source regions are least likely to be found here.
low latitudes
high latitudes
polar regions
middle latitudes
middle latitudes
Which of the following air mass types generally has the highest dew point?
Continental Polar
Continental Tropical
Maritime Tropical
Maritime Polar
Maritime Tropical
Most of the air masses in the central part of the United States are either
maritime polar or maritime tropical.
maritime polar or continental polar.
continental polar or maritime tropical.
continental tropical and maritime polar.
continental polar or maritime tropical.
Which of the following best defines a front?
A narrow boundary between air masses where precipitation occurs
A narrow boundary separating cold air from colder air
A narrow boundary between air masses where cloudiness occurs
A narrow boundary separating different air masses
A narrow boundary separating different air masses
If you observe short, intense, scattered rainfall as a front passes, which of the following are you most likely to be experiencing?
A cold front
A warm front
A stalled front
A stationary front
A cold front
Between a cold front and a warm front, we find
a warm, moist, and unstable air mass.
a cold air mass.
a dry air mass.
a very stable air mass.
a warm, moist, and unstable air mass.
This type of front has a mass of warm air cut off from the surface.
occluded front
warm front
stationary front
cold front
occluded front
The sources of air masses occur only in low and high latitudes because
there are no oceans in the middle latitudes.
there is insufficient contrast in surface type (land vs. ocean) in the middle latitudes.
middle-latitude weather is not variable enough.
middle-latitude weather is too variable.
middle-latitude weather is too variable.
Northeasters
are associated with warm winds.
are rarest in winter and early spring.
often bring heavy snowfall.
are associated with anticyclones.
often bring heavy snowfall.
Which air mass is responsible for bringing virtually all of the moisture that impacts the United States east of the Rocky Mountains?
Continental Tropical
Maritime Tropical
Maritime Polar
Continental Polar
Maritime Tropical
After passing over a series of mountain ranges, maritime polar air becomes
drier.
colder.
warmer.
more moist.
drier.
Which of the following best describes midlatitude cyclones that move along the U.S. East Coast and bring moist maritime air towards New England, often producing cold winds and heavy snowfall in winter?
Overrunning
Southeasters
Northeasters
Drylines
Northeasters
Which of the following fronts do not separate tropical from polar air masses?
warm
cold
stationary
occluded
occluded
________ fronts usually have showery precipitation while ________ fronts usually have continuous precipitation.
Occluded; squall lines
Cold; warm
Warm; cold
Occluded; cold
Cold; warm
This is the first type of cloud an observer will see when a warm front is approaching
nimbostratus.
altostratus.
cirrus.
low-level stratus.
cirrus.
Which of the following frontal systems often move with greatest forward velocity?
stationary front
warm front
cold front
occluded front
cold front
Drylines in the United States
separate saturated air from unsaturated air.
can lead at worst to mild thunderstorms.
typically have continental air to the west.
can lead to a situation in which warm, moist air overtakes dry, cold air.
typically have continental air to the west.
According to the polar front theory,
midlatitude cyclones form along a boundary separating polar air and warmer air to the south.
midlatitude cyclones create fronts in the polar regions.
midlatitude cyclones form along a boundary separating frigid Arctic air with slightly colder polar air.
midlatitude cyclones form in front of several large air masses.
midlatitude cyclones form along a boundary separating polar air and warmer air to the south.
Within a Rossby wave, which of the following locations generally has the largest absolute vorticity?
At the trough axis
East of the trough
At the ridge axis
Beneath a ridge
At the trough axis
Which of the following are associated with the formation and intensification of surface mid-latitude cyclones?
upper-level divergence and lower-level convergence
upper-level convergence and lower-level convergence
upper-level convergence and lower-level divergence
upper-level divergence and lower-level divergence
upper-level divergence and lower-level convergence
At which of the following levels does the wind direction most closely approximate the path that a midlatitude cyclone tends to take?
The 500 mb level
The jet stream
The 700 mb level
The 300 mb level
The 500 mb level
In the conveyor belt model, this belt enters the storm flowing westward toward the surface cyclone.
cold conveyor belt
wet conveyor belt
dry conveyor belt
warm conveyor belt
cold conveyor belt
According to the polar front theory, cyclogenesis begins when
cold air begins to advance southward and warm air begins to advance northward.
an occluded front is formed.
cold air begins to rise above the warmer air.
cold air begins to advance northward and warm air begins to advance southward.
cold air begins to advance southward and warm air begins to advance northward.
In which of the following areas is cyclogenesis most likely to occur?
In regions of strong temperature contrasts
In the tropics
In river valleys
Beneath an upper-air ridge
In regions of strong temperature contrasts
Mid-latitude cyclones in the Northern Hemisphere typically travel primarily in this direction.
east
north
south
west
east
The warm sector between the warm and cold fronts is generally characterized by
clear conditions.
declining dew points.
squall lines immediately to the west of the warm front.
southeasterly winds.
clear conditions.
A mid-latitude cyclone reaches its most intense stage when
the storm system undergoes occlusion.
the storm moves over water.
the warm sector reaches its maximum strength.
the storm moves over cold air.
the storm system undergoes occlusion.
Earth vorticity
is a function of latitude.
does not affect absolute vorticity.
is greatest at the Equator.
is vorticity relative to the earth's surface.
is a function of latitude.
Which of the following statements is NOT true?
Upper level divergence causes high pressure at the surface.
Rossby waves can generate upper-level divergence.
Rossby waves can generate upper-level convergence.
Upper-level divergence increases the strength of mid-latitude cyclones.
Upper level divergence causes high pressure at the surface.
Zonal patterns
show little north-south displacement between contour lines on a 500 mb map.
feed the formation of intense anticyclones.
create substantial regions of heavy weather.
feed the formation of intense cyclones.
show little north-south displacement between contour lines on a 500 mb map.
________ motions within anticyclones generally bring ________ skies.
Sinking; clear
Rising; cloudy
Sinking; cloudy
Rising; clear
Sinking; clear
The stepped-leader
creates the pathway for the flow of electrons.
moves downward in one continuous movement.
has no similarities to a dart leader.
occurs after the formation of the return stroke.
creates the pathway for the flow of electrons.
Thunder
is the cause of heat lightning.
always appears to the listener as a sharp clap.
moves at the speed of light.
results from the explosive expansion of air.
results from the explosive expansion of air.
Which of these can be characteristics of severe thunderstorms?
tornadoes
all of these
hailstones one inch or larger in diameter
wind speeds in excess of 58 mph
all of these
The formation of a mesocyclone requires
vertical wind shear.
the presence of a funnel cloud.
the presence of stratocumulus clouds.
the existence of a wall cloud.
vertical wind shear.
Waterspouts tend to form in areas with ________ water and ________ atmospheric conditions.
cold; unstable
cold; stable
warm; stable
warm; unstable
warm; unstable
A typical cloud-to-ground lightning event consists of
a combination of ionospheric discharge and wind shear.
a massive release of latent heat.
a single electrical discharge.
several distinct steps that look to the human eye like a single lightning strike.
several distinct steps that look to the human eye like a single lightning strike.
Which portion of the lightning process is the most visible?
return stroke
stepped leader
charge separation
dart leader
return stroke
Supercell storms
account for a majority of tornadoes.
are not readily visible on Doppler radar.
are larger than mesoscale convective complexes.
do not exhibit any rotational aspects.
account for a majority of tornadoes.
An outflow boundary is
a favorable place for future severe storm development, especially if two intersect.
all of the above
can be clearly seen on radar images.
the leading edge of cold air from a thunderstorm downdraft.
all of the above
A common Doppler radar signature associated with a supercell tornado is the
roll cloud.
hook echo.
shelf cloud.
gust front.
hook echo.
Air mass thunderstorms
extinguish themselves through the formation of extensive downdrafts.
are associated with severe weather.
often last for several hours.
usually form at the borders of air masses.
extinguish themselves through the formation of extensive downdrafts.
Tornadoes
are associated primarily with synoptic-scale cyclones.
always rotate clockwise in the Northern Hemisphere.
are associated with cumulonimbus clouds.
are rare outside the United States and southern Canada.
are associated with cumulonimbus clouds.
This is NOT a significant factor in explaining why the United States experiences so many tornadoes:
bordered by a cold ocean current on west coast.
lack of major east-west mountain range in east.
spans wide range of latitudes.
relatively flat in eastern portion.
bordered by a cold ocean current on west coast.
A strong surface pressure gradient across the continental United States might consist of a cyclone at 990 mb that is 800 km away from a 1020 mb anticyclone. In contrast, a tornado can generate a 100 mb pressure difference between its core and a location 0.5 kilometers away.
About how many times greater is the pressure gradient of this tornado?
To calculate the pressure gradient, find the difference between the two pressures and divide by the distance.
10 times greater
50 times greater
5000 times greater
50,000 times greater
5000 times greater
Tropical storms in the East Pacific
eventually pass over Hawaii.
miss Mexico.
generally move westward.
are the typhoons that hit Asia.
generally move westward.
Hurricanes
generally have very little thunder and lightning.
are larger than Mid-latitude cyclones.
never spawn tornadoes.
are smaller than Mid-latitude cyclones.
are smaller than Mid-latitude cyclones.
Hurricanes have
more fronts than a midlatitude cyclone.
between one and three fronts.
no fronts.
the same number of fronts as a midlatitude cyclone.
no fronts.
Note 
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