Final Flashcards
What is the change of state of ice into vapor?
Sublimation
What is the amount of pressure change that occurs over a given horizontal distance?
Pressure Gradient
What type of uplift occurs as air is lifted over a mountain barrier?
Orographic
What is an apparent force created by the rotation of the earth?
Coriolis
Wind aloft that blows parallel to the isobars or contours
Geostrophic
Clouds with the greatest vertical growth:
Cumulonimbus
The max pressure that water vapor would exert if the air were saturated
Saturation Vapor Pressure
A descending layer of dry air can form this phenomenon
Subsidence inversion
Wispy, high clouds
Cirrus
The process by which a parcel expands and cools or compresses and warms with no interchange of heat with its surroundings:
Adiabatic
A fog that commonly forms on clear nights, with light or calm winds:
Radiation fog
Clockwise shift in wind direction as you climb out of the boundary layer:
Veering
A measurement of meteorological conditions between the ground and some higher level in the atmosphere:
Sounding
These particles serve as surfaces on which water vapor may condense:
Condensation Nuclei
Relative humidity is typically the highest during the early hours of the morning just after sunrise. T/F
True
The Coriolis force makes objects in motion appear to curve to the east in either the northern or Southern Hemisphere. T/F
False
Valleys are more susceptible to radiation fog than are hilltops. T/F
True
When the air is saturated an increase in air temp will cause condensation to occur. T/F
False
Closer the contours on a constant pressure chart, the faster the wind speed at that level. F/T
True
The Coriolis force is zero at the equator. T/F
True
Latent heat is released during evaporation. T/F
False
Air is normally rising above a region of surface high pressure. T/F
False
Warming a parcel of air above the temperature of the environment around it will tend to make the atmosphere more unstable. T/F
True
Near the earth’s surface at the same temperature and level in the atmosphere, warm humid air is less dense than warm dry air. T/F
True
Dew is most likely to form on clear, windy nights. T/F
False
Air flow around a high pressure is anticyclonic. T/F
True
The process of water changing from a liquid to a vapor is called:
Evaporation
The temp the air must be cooled for saturation to occur is called the: Temperature.
Dew-point
A: Uses wet-bulb and dry-bulb temperature to obtain relative humidity.
Psychrometer
Clouds with a lens shape that often form over and downwind of the mountains are called:
Lenticular
If an air parcel if given a push upward and it falls back to its original position, the atmosphere is said to be:
Stable
What are used to measure wind speed at automated weather observation systems?
Anemometer
Another name for “water seeking” condensation nuclei is:
Hygroscopic
A change in: And/or a change in: Will result in a change in relative humidity.
Temperature, water vapor
Fog that forms as relatively warm air moves over a colder surface is called:
Advection fog
A low cloud that produces steady precipitation is called:
Nimbostratus
When the atmosphere is absolutely unstable the environmental lapse rate is: The dry adiabatic rate.
Less than
Air is in hydrostatic equilibrium when the upward pressure gradient force is balanced by the downward:
Force of Gravity
When the air temperature increases, the saturation vapor pressure:
Increases
The Coriolis force is strongest when the wind speed is: and the latitude is:
High, high
Is a dry parcel is lifted 6,000’ into the atmosphere, it will be:
18 degrees cooler than what is was before it was lifted.
The rate at which the air temp changes inside a rising or descending parcel of saturated air is called the
Moist Adiabatic Lapse Rate
An instrument that is used to measure cloud base height above the ground:
Ceilometer
These two conditions, working together, will make the atmosphere the most stable:
Warm the surface and cool the air aloft
The temperature-dew point spread is 8 degrees C what is the estimated height of the cumulus cloud bottoms above the surface?
3,200’ AGL
Given the following METAR:
KFTW 111914Z 250007G22KT 3SM R16/5500VP6000FT +RA BR BKN023 BKN 040 OVC070 18/16 A2982 RMK A02 PK WND 27044/1900 WSHFT 1857
Wind shifted at 1857Z
Given the following METAR:
KAPA 121453Z 34006KT 4SM RA BR BKN006 OVC015 07/06 A3045 RMK A02 SLP299
What is the height of the cloud ceiling?
600’ AGL
Given the following METAR:
KCRH 111915Z AUTO 12018KT 2 1/2SM BR BKN021 BKN026 BKN030 25/24 A2990 RMK A01
What is true?
The visibility is 2 1/2 SM
Given the following METAR
KCOS 121454Z 36013G22KT 9SM BKN018 08/06 A3042 RMK PK WND 36030/1426
What is the observed peak wind?
30 knots at 1426Z
The transfer of energy through molecule motion:
Conduction
A condition caused by a lack of oxygen to the brain:
Hypoxia
An elongated high-pressure area:
Ridge
Energy transferred by electromagnetic waves:
Radiation
Gas that strongly absorbs ultraviolet (UV) radiation in the stratosphere:
Ozone
A measure of the average speed of the air molecules:
Temperature
Lines of equal pressure:
Isobar
Temperature scale that begins at absolute zero:
Kelvin
The transfer of heat that depends upon the movement of air:
Convection
Protects instruments from direct sunlight and weather elements:
Stevenson screen
What percent does each of the following gases occupy in a volume of air:
Nitrogen:
Oxygen:
78%, 21%
The primary source of energy for the earth’s atmosphere is the:
Sun
The atmospheric boundary that separates the stratosphere from the mesosphere is the:
Stratopause
An elongated region of low pressure is called a:
Trough
Water vapor is gas. T/F
True
A change in air density can bring about a change in air pressure. T/F
True
In a standard atmosphere about half of our atmosphere is below 22,000’ MSL. T/F
True
Air is a good conductor of heat. T/F
False
Water warms and cools more slowly than land. T/F
True
The standard atmosphere cools at a rate of 3 degrees C per 1,000-foot increase in altitude. T/F
False
At a constant pressure, cold air is more dense than warm air:
False
METARS are issued 5 times per day. T/F
False
On a constant pressure chart, higher heights are associated with lower temperatures and lower pressures. T/F
True
Surface analysis charts are issued every 3 hours. T/F
True
METAR wind direction is reported referenced from magnetic north. T/F
False
Airflow rotates clockwise around an area of high pressure. T/F
True
Air density normally:
Decreases with increasing height
A force exerted on a unit area describes air is:
Pressure
The: Affects radio transmissions on earth.
Ionosphere
As the average speed of air molecules decreases, the temp of the air:
Decreases
Because the moon has no atmosphere it can only cool by:
Radiation
Water vapor and carbon dioxide are effective absorbers of:
Infrared radiation
In clear weather the air next to the ground is usually: than the air above during the night, and: than the air above during the day.
Colder, warmer
A pilot flies from a region of cold air into a region of warm air. In the warm air the aircraft is indicating the same altitude as it did in the cold air, yet the aircraft’s true altitude would be:
Higher than indicated altitude
Given the METAR:
KHWO 051753Z 17015G19KT 10SM FEW047 33/23 A2990 RMK A02 SLP126
What is the altimeter setting?
29.90” Hg
Given the METAR:
KHWO 051753Z 17015G19KT 10SM FEW047 33/23 A2990 RMK A02 SLP126
What is the sea level pressure in millibars?
1012.6mb
Given the METAR:
K1J0 051758Z AUTO 18017G32KT 10SM 30/23 A2961 RMK A02 PK WND 15022/1743 SLP987
What is the sea level pressure in millibars?
998.7 mb
Given the METAR:
K1J0 051758Z AUTO 18017G32KT 10SM 30/23 A2961 RMK A02 PK WND 15022/1743 SLP987
What is the peak wind reported?
33 knots from 150 degrees true
What is the sea level pressure in inches of mercury if the airport lies at an elevation of 5,885’?
KAPA 221753Z 20011KT 10SM CLR 02/M09 A3001 RMK A02 SLP206 T00221094 10022 21106 50004
30.01” hg
Short waves are upper level disturbances that can provide the necessary spark to kick off a mid-latitude cyclone. T/F
True
The 500 mb level is higher behind the cold front than in the warmer air ahead. T/F
False
The mid-latitude cyclone derives its energy from:
- the rising of warm air, sinking of cold air
- condensation
- wind
What causes a surface low pressure system to strengthen?
More divergence aloft than convergence at the surface
The upper level winds associated with a surface mid-latitude cyclone generally causes the storms to move in which direction?
Northeast
Cloud bases are reported on METAR reports as:
Height above ground level
Marginal VFR is defined as:
Visibility 3-5 SM and cloud ceiling 1000’-3000’
VFR (as weather flying category) is considered:
> 5 SM visibility and >3000’ cloud ceiling
Which cloud layer would not be considered a ceiling?
SCT
Based on the METAR what is the ceiling?
KRUT 101656Z AUTO 33012G16KT 6SM FEW005 SCT010 BKN024 OVC048 01/M01
2400’
Based on the METAR what weather flying category currently exists?
KRUT 101656Z AUTO 33012G16KT 6SM FEW005 SCT010 BKN024 OVC048 01/M01 A3007
MVFR
On an IR satellite image, brighter white areas represent:
Solids with high tops
Which scenario is more conductive for radiation fog formation?
Around sunset after a clear day
Which cloud type is more likely to prevent VFR flight from your local airport?
Stratus
Saturated air cools faster than dry air when there is a source of lifting. T/F
False
What type of fog is common around the San-Francisco Bay Area?
Advection fog
What type of fog is referred to as “valley fog”
Advection fog
This cloud type is characterized by the Latin root for “Heap”
Cumulus
Alto-cumulus standing lenticular (ACSL) clouds are indicative of:
A stable atmosphere and strong winds aloft
Frost commonly forms on large portions of the aircraft structure first. T/F
False
What conditions are necessary for the formation of frost?
Dew point below zero and a surface temp below the dew point
What is true regarding frost?
All frost must be removed from an aircraft prior to flight.
Generally speaking an aircraft descending into the boundary layer can expect the winds to:
Decrease and back
Geostrophic balance is achieved when the Pressure Gradient Force is balanced with:
The Coriolis Force
Winds around a low-pressure region generally flow:
Counterclockwise
In a winds aloft forecast, wind speed is omitted if the forecast level is within 3000’ of the station elevation. T/F
False
Terminal aerodrome forecasts (TAFs) cover a distance of:
5 SM from the center of the airport
Standard TAFs are valid for: Hours with some international locations valid for : Hours.
24,30
TAFs are issued how many times per day?
4
TAFs are issued at what times?
0000Z/0600Z/1200Z/1800Z
During the summer the polar jet stream moves further south and the subtropical jet stream moves further north. T/F
True
During the summer, the subtropical jet stream strengthens as it moves further north. T/F
False
Which jet stream forms where the Polar and Ferrel cell meet.
Polar jet stream
Higher temps on the south side of the polar front, as compared to the colder temps to the north side of the polar front lead to:
Higher heights and heights pressure aloft
Which weather product is best to observe the location and intensity of the jet stream?
300 mb constant pressure charts
The flow of air aloft parallel to the contour lines is known as:
Geostrophic balance
Jet stream generally occur in which layer/boundary of the atmosphere?
Tropopause
The polar jet stream occurs at a higher altitude than the subtropical jet stream. T/F
False
As air moves north the earth’s circumferences decreases. This causes the wind speed to increase due to:
Conservation of angular momentum
Jet streams in the Southern Hemisphere flow from East to West. T/F
False
The cloud that forms along the leading edge of a cold surface gust front in a multicell thunderstorm is called a:
Shelf cloud
Funnel clouds are a result of:
Intense low pressure immediately below the base of the cloud
Occasionally a supercell thunderstorm can produce an updraft so strong that it can penetrate the tropopause. Known as:
Overshooting top
Electrical charges are carried from the base of the cloud towards the ground by:
Stepped leader
This is the positive charge of a surface reaching up towards the bottom of the thunderstorm.
Positive streamer
The development of thunderstorms requires:
Unstable air
Relatively high humidity
Source of lifting
The proceeds in which the friction of falling precipitation draws in drier air from outsider of the cloud is known as:
Entrainment
During the life cycle of a thunderstorm which stage os characterized predominantly by:
Dissipating
Which weather characteristics signals the mature stage of a thunderstorm?
The start of rain at the surface
Growth rate of the cloud is at a maximum
Strong turbulence in the cloud
Fast flowing current of air concentrated in a narrow band:
Jet Stream
Pressure systems found near latitude 30 degrees:
Subtropical highs
Air mass responsible for hot, dry summer weather over portions of Arizona and New Mexico:
CT
Lines of equal air temp:
Isotherms
Atmospheric events that occur on a global scale:
Macroscale
Semi-permanent pressure system associated with the polar front:
Subpolar low
Winds observed behind the polar front in the polar cell:
North easterlies
The thermally indirect cell:
Ferrel cell
The coldest of all air masses:
CA
Embedded thunderstorms are often associated with this phenomenon:
Occluded Front
Another name for longwaves:
Rossby waves
The development or strengthening of a mid latitude cyclonic storm system:
Cyclogenesis
Boundary separating northeast trade winds in the northern hemisphere with the southeast trade winds of the Southern Hemisphere:
ITCZ
The rising of warm air over cold air:
Overrunning
This process is the most efficient means of precipitation production:
Ice crystal process
The presence of this precipitation type at the surface is an indication of freezing rain aloft:
Sleet
The polar jet stream is normally observed at a higher altitude than the subtropical jet stream. T/F
False
At the surface during the passage of a cold-type occluded front the coldest air is observed ahead of the advancing front. T/F
False
The trade winds flow from the northeast to the southwest in the northern hemisphere. T/F
True
Continental polar air masses in the United States are observed only in winter. T/F
False
The tropopause is higher at the equator than at the poles. T/F
True
Occluded fronts may form as a cold front over takes a warm front. T/F
True
Warm fronts generally move faster than cold fronts. T/F
False
The polar jet stream moves farther south in the summer. T/F
False
The eastern slope of the Rockies can be a region of cyclogenesis. T/F
True
A dust devil is a good example of a mesoscale event in the atmosphere. T/F
False
On a surface weather map, a cold front is depicted with a blue line and triangles pointing toward the cold air. T/F
False
The rising of warm air and the sinking of cold air provide energy for a developing mid latitude cyclone. T/F
True
A back door cold front moving through Colorado would most likely be moving from east to west. T/F
True
The slope of a typical warm front is usually much steeper (more vertical) thank that of a cold front. T/F
False
The 300 mb Constant Pressure Chart is often used in determining the location of the jet stream. T/F
True
The frontal surface of a cold or warm front always tilts towards the warm air mass as you move up in the atmosphere. T/F
False
Precipitation that falls into a very dry atmosphere below a cloud and evaporates before reaching the surface is called:
Virga
A: Rain gauge is commonly used to measure precipitation amounts at AWOS and ASOS automated weather stations.
Tipping bucket
The general circulation model that accounts for the rotation of the earth is called the: Model
Three cell
The jet stream situated at the tropopause near the polar front is called the:
Polar jet
:are responsible for the existence if the major deserts of the world observed near 30degree latitude.
Subtropical highs
The pressure ahead of a cold front: and then rapidly: after the front has passed.
Falls,rises
The: Conveyor belt results from air passing under the warm front where it picks up moisture then rises in the heart of the low-pressure region.
Warm
Lake-effect snows are:
Localized snowstorms that form on the downwind side of a lake.
What is not considered a semi-permanent high or low pressure?
Siberian High
In the conveyor belt model of rising and descending air, one would expect the dry conveyor belt airstream to be located:
Behind the surface of a cold front
The horse latitudes are the result of:
The subtropical highs
If an upper level trough is located to the west of a surface mid latitude cyclone, the surface storm will probably move toward the:
Northeast
Typically winter mP air masses along the Atlantic coast of North America are less common than mP air masses along the Pacific coast mainly due to the fact that:
The prevailing winds aloft are westerly
The three-cell model of general circulation, areas of surface low pressure are found near:
The equator and 60degree latitude
When a low pressure system is “vertically stacked” the system will gradually:
Dissipate
