Aviation Weather Exam 3 Quizzes

Thermals tend to be smaller and weaker in the afternoon

False

In the Western US, storms will develop at _____ altitudes than in the Eastern US

higher

Limited cloud growth occurs in a cold airmass ____ the cold front due to a(n)___ layer near the top

behind, stable

A super-cell always produces large hail and tornadoes

False

A cloud top will end at the

equilibrium level

A violently rotating, funnel shaped-column of air that extends from the base of a cumulonimbus cloud to the ground

tornado

If there is precipitation and downdraft, but no thunder and lightening, the storm has not entered the mature stage

True

Thunderstorms are rooted in

dry convection

A parcel of air that cools superadiabatically cools at what rate

Greater than 3ºC

A continuous updraft is associated with this stage

Cumulus

Begins When the precipitation-induced downdraft reaches the ground

Mature

This stage is dominated by downdrafts

Dissipating

If a convective cloud becomes a cumulonimbus it results in a SPECI, it should be considered a thunderstorm regardless of activity

True

A rising bubble of warm air

Thermal

A dust devil is essentially a very small tornado

False

What aviation concerns do thunderstorms produce? Select all that apply

icing, wind shear, significant turbulence

Above the convective condensation level, air cools at the _____ adiabatic lapse rate. It differs due to the ______ of latent heat during condensation

saturated, release

A downdraft produced by precipitation inside a thunderstorm is called

precipitation-induced downdraft

A group of cells in various stages of development. Their proximity allows interaction and prolongs the lifetime of the group. What type of thunderstorm is this

Multi-cell

A sharp boundary found on the edge of the pool of cold air that is fed by downdrafts that spreads out below a thunderstorm

gust front

The ground is much warmer than the air above it, and it cools superadiabatically

dry convection

Saturated air that is rising because it is warmer than its surroundings

cloudy convection

A thunderstorm is always accompanied by lightning and thunder

True

A downburst caused by precipitation-induced downdraft that is exceptionally strong and small

microburst

When the altitude of cumulus clouds reaches the freezing level, the cloud rapidly grows via the

ice crystal process

The lowest level at which condensation will occur as a result of convection due to surface heating

Convective condensation level

May produce small hail and/or wind gusts less than 50 knots, and/or microbursts

airmass

Wind gusts more than 50 knots and/or hail three-quarters of an inch in diameter or larger, and/or strong tornadoes

severe

Which stage of a thunderstorm has the greatest intensity

mature

Consider a land breeze, wind speeds are proportional to

Land-water temperature difference

Select all that are examples of warm downslope winds

Foehn winds, Santa Ana winds, Chinook winds

A sea breeze front produces a large area of stability and thunderstorms are less likely

False

Mountain lee waves are an example of

externally driven winds

The sea breeze circulation is sometimes visible as clear ocean air moves inland and polluted city air moves out to sea

True

Cold, dense air sinking downslope is accelerated by gravity which strengthens the downslope wind. This is called

drainage winds

A mountain breeze is another version of upslope wind

False

Sea breezes

intensify during the day

Mountain ranges are always parallel so lee wave speed and direction is likely uniform in most areas

False

Sea breezes blow ___ the sea; land breezes ____ the land; valley breezes ____

the valley (upslope); mountain breezes ___ the mountain (downslope)

from, from, from, from

High, broad ridges with steep slopes often produce ____ amplitude lee waves

large

Thermally driven means the winds are caused by

local differences in radiational heating or cooling

A valley breeze that blows along the centerline of a valley, moves towards

higher terrain

A valley breeze is another version of upslope wind

true

Consider lee wave formation, sea level pressure is lower on the west sides in all cases

false

A sea breeze is common in _____ regions in the ____ when the land surface is ____ than the sea surface

coastal, daytime, warmer

Considering mountain lee waves, the stronger the wind speed, the ____ the wave

longer

Select all that are thermally driven local winds

land breeze, mountain breeze, valley breeze, sea breeze

Land and sea breezes only occur along the ocean coastlines, and do not occur on the Great Lakes coastlines

False

A land breeze isn't as deep as a sea breeze due to stable night conditions over land

true

With a warm front, the most critical period for LLWS is

before the front passes

In what type of thunderstorm are microbursts considered most dangerous to occur in

single cell

The frontal zone contains both horizontal and vertical wind shear

true

Where is clear air turbulence most likely to be encountered

jet stream

An aircraft may safely land or take off in the face of an approaching thunderstorm, and wind shear is only experienced when directly underneath the storm

false

Because of nighttime surface-based temperature inversions, expect wind shear whenever the wind speed between 2,000' and 4,000' AGL is

at least 25 knots

If LLWS is encountered on takeoff and headwind shears to a tailwind, the climb rate will

decrease

If LLWS is encountered on approach and a tailwind shears to a headwind, the aircraft will likely

overshoot the runway

Consider airmass wind shear, when will the LLWS decrease

with the sunrise as the ground heats up

If you had a 15 knot headwind, and that changed to a 15 knot tailwind, what is the total wind shear

30 knots

As the vortex ring of the microburst rolls upward, the wind direction reverses 180º

true

Strong wind shear occurs associated with cyclones is more prominent in

the cooler months of the year

Wind shear below 2,000' AGL along the final approach path or along the takeoff and initial climb out path

low level wind shear

Consider the frontal zones, LLWS will occur before a cold front passes and after a warm front passes

false

During departure under conditions of suspected LLWS, a sudden decrease in headwind will cause a loss of airspeed ____ the decrease in wind velocity

equal to

A change in wind direction and/or speed within a very short distance

wind shear

What is the most correct way to identify a microburst in a dry climate

virga and a dust ring at the surface

Select all that are causes of wind shear

temperature inversions, microbursts, fronts

The WSR-88D has greater power and provides a narrower radar beam in comparison to the Terminal Doppler Weather Radar (TDWR). This provides significantly more detailed wind shear measures

false

Wind shear that develops near the ground or at night under fair weather conditions in the absence of strong fronts

airmass wind shear

The wind condition that prolongs the hazards of wake turbulence during landing is a

light-quartering tailwind

To change altitude for clear air turbulence

watch your temperature for a few minutes. If it is rising, climb, if it is falling descend, if it is spread, do either: true

Turbulence causes changes in altitude and/or attitude but aircraft remains in positive control at all times. What intensity is this

moderate

Accidents due to loss of control in adverse wind conditions can occur during taxiing, takeoff, and landing

true

Thermal turbulence is more prominent over

high terrain

Aviation turbulence is reported based on the response of the aircraft, NOT the current state of the atmosphere

true

The type of approach and landing recommended during gusty wind conditions is a ________ approach and landing

power-on

Reports of severe turbulence in clear and cloudy air surrounding a thunderstorm are not well documented or understood

true

The characteristics of an unstable airmass moving over a warm surface are

turbulence, good visibility, cumliform clouds

Where does turbulence reach its greatest intensity around a mountain

Downwind (leeward) side

Mechanical turbulence occurs most over flat ground when wind speeds are slow

false

Rotor clouds associated with mountain lee waves do not provide great risk and do not need to be avoided

false

Surface winds in excess of 50 knots can cause mechanical turbulence up to 3,000' AGL

true

Turbulence should be reported as better than actual conditions, rather than worse, if the pilot is unsure

false

As a good rule of thumb

fly an altitude of ___ higher than the height of the mountain range: 50%

Clear air turbulence may occur near non-convective clouds

true

Most hazardous to least

in the thunderstorm, below the thunderstorm, under the anvil cloud

When is wake turbulence most dangerous

near the ground

What should a pilot climb to in attempt to avoid fair weather thermals

capping stable layer

What kind of turbulence occurs within the boundary layer

Low level turbulence