WX 201 Test 2-1

Radiation fog forms best on a

clear winter night with a slight breeze

At Earth's surface, a rising saturated air parcel cools at the

moist adiabatic rate

Light or moderate-but-steady precipitation is most often associated with ____ clouds.

nimbostratus

Hail is usually associated with what cloud?

cumulonimbus

Mammatus clouds most frequently form on the underside of ____ clouds.

Cumulonimbus

Thunderstorms that produce tornadoes

Have rotating updrafts

Which of the following might be mistaken for hail?

graupel

Supercell thunderstorms are different from ordinary thunderstorms in that supercell thunderstorms

have a strong updraft and downdraft

Inversions that form as air slowly sinks over a large area are called _____ inversions

subsidence

Contact freezing is

the freezing of a supercooled droplets by contact with a nucleus.

An inversion represents an extremely stable atmosphere because air that rises into the inversion will eventually become ____ and ____ dense than the surrounding air.

colder; more

Particles that serve as surfaces on which water vapor may condense are called

condensation nuclei

Upslope fog forms because air ___ as it flows up a hill or mountain range.

cools adiabatically

Condensation is most likely to happen when air ______ and the speed of the water vapor molecules _____.

cools; decreases

The cloud with the greatest vertical growth is

cumulonimbus

Which cloud type below would most likely form in an unstable atmosphere?

cumulonimbus

As the difference between the air temperature and the dew point increases, the relative humidity:

decreases

Which of the following is the BEST indicator of the actual amount of water vapor in the air

dew point temperature

The lightest form of rain is

drizzle

Fog that most often forms as warm rain falls into a cold layer of surface air is called

evaporation (mixing) or frontal fog.

Large raindrops fall ____ than smaller raindrops, and have a ____ terminal velocity than small raindrops.

faster than; greater

When radiation fog "burns off", the fog tends to dissipate:

from the bottom up

When temperatures are below freezing, the temperature to which air must be cooled in order for a phase change (from liquid to ice) to occur is called the

frost point

For sub-freezing temperatures, the saturation vapor pressure just above a liquid water surface is ____ the saturation vapor pressure above an ice surface.​

greater than

Suppose the dew point of cold outside air is the same as the dew point of the air indoors. If the door is opened and cold air replaces some of the warm air, then the new relative humidity indoors would be

higher than before.

which of the following is the least likely during the passage of a gust front

increase in temperatures

If the air temperature remains constant, evaporating water into the air will ____ the dew point and ____ the relative humidity.

increase; decrease

The difference between "moist" and "dry" adiabatic rates is due to the fact that

latent heat is released by a rising parcel of saturated air.

An ordinary thunderstorm is most intense during the ____ stage.

mature

Advection fog is often observed along the Pacific coast during summer, as westerly winds carry moist air toward the shore. The fog forms because the surface water near the coast is ____ the surface water farther offshore.

much colder than

which of the following will increase in a rising parcel of air?

relative humidity

In the solid state called ice, the shape and charge of water molecule helps arrange the molecules into ____ crystals

six-sided (hexagonal)

The main difference between a cloud drop and a raindrop is its

size

Air which resists vertical displacements is considered to be:

stable

If the air temperature outside increased, with no addition or removal of water vapor, the actual vapor pressure would

stay the same

Which cloud would most likely produce drizzle?

stratus

which of the following will increase the relative humidity in a home during the winter

taking a shower and letting the air circulate through the home

If an air parcel is given a small push upward and it continues to move upward on its own accord, the atmosphere is said to be

unstable

If fog is forming at Denver, Colorado (located on the eastern side of the Rocky Mountains), and the wind is blowing from the east, then the fog is most likely

upslope fog

At what time of day is the relative humidity normally at a minimum

when the air temperature is highest

Ordinary thunderstorms only last about one hour and begin to dissipate when

when the downdraft spreads throughout the cloud and cuts off the updraft

Suppose it is snowing outside and the air is saturated. The air temperature and dew point are both 15°F, and the actual vapor pressure is 3 mb. If this air is brought indoors and warmed to 75°F, what would the relative humidity of this air be, assuming that its moisture content does not change? (The saturation vapor pressure at 75°F is 30 mb).

10 percent

Which environmental lapse rate represents the most unstable atmosphere in a layer of unsaturated air?

11°C per 1,000 m

If he environmental lapse rate is 5°C per 1,000 m and the temperature at Earth's surface is 25°C, then the air temperature at 2,000 m above the ground is

15°C

If you see a lightning stroke and then, 15 seconds later, hear the thunder, the lightning is about ____ miles away.

3

A high water vapor pressure indicates a

A relatively large number of water vapor molecules in the air

the highest frequency of thunderstorms in the United States occurs in

Florida

For____to occur, separate regions containing opposite electrical charges must exist within a cumulonimbus cloud.

Lightning

The largest amount of latent heat gets released in a _____ parcel of _____ saturated air.

Rising; warm

Supercell thunderstorms differ from ordinary cell (air mass) thunderstorms because

The updraft in a supercell thunderstorm is longer-lasting and rotates

Just above cumulus clouds, you would expect to find

a stable layer

An amount of precipitation measured to be less than one hundredth of an inch (0.25 mm) is called:

a trace

If the environmental lapse rate is less than the moist adiabatic rate, the atmosphere is

absolutely stable

Clouds are classified by their

altitude and appearance

Altocumulus clouds that show vertical development and produce tower-like extensions are called

altocumulus castellanus