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76 Cards in this Set
- Front
- Back
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What Does Natural Air consist of?
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Dry air plus varoius amounts of water vapor and condensation nuclei.
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Height of Troposphere:
at equator: at poles: |
E: 60,000ft
P: 25,000ft |
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Where does weather occur?
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Troposphere
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What are the conditions affecting atmosphere circulation (3-cell theory)
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1. uneven heating of earth's surface
2. Rotation of the earth 3. Coriolis force |
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What direction are the prevailing winds in U.S.:
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W to E
(Westerly) |
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What are the 4 methods of heat transfer?
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Radiation
Conduction Convection Advection |
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Transfer of heat by electromagnetic waves
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Radiation
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Transfer of heat by physical contact
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Conduction
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transfer of heatby way of gas
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Convection
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Horizontal movement and is greater than vertical movement
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Advection
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Standard lapse rate
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2 deg per 1000ft
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When temperature increases with altitude rather than decreases
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temperature inversions (warmer air above colder air)
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Ca
cP mP mT cT E |
Continental artic-coldest dry
Continental polar-cold dry Maritime polar-cold moist Maritime tropical-warm moist Continental tropical-warm dry equatorial - warmest moist |
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W stands for...
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Stable
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k stands for
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unstable
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Standard MSL pressures:
Mercury Millibars |
Mercury 29.92
Millibars 1013.2 mb or hp |
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elongated area of high pressure
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ridge
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elongated area of low bressure
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trough
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A _______ pressure gradient force is indicated by closely apaced isobars. (strong winds)
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Strong / Steep
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A _______ pressure gradient force is indicated by widely spaced isobars (light to moderate winds)
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Weak / flat
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_____ force acts perpendicular to the right of the wind (on any steered objects on the northern hemisphere)
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Coriolis force
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Above the friciton level (_____ ft) coriolis modifies gradient and causes a ____ flow parallel to the isobars.
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2000
clockwise |
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Below friction lever 2000ft winds flow across isobars high to low pressure.... How many degrees?
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30 degrees left
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Flying High to Low
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Look out below
you are reading higher on your altimeter than you truly are |
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the process when vapor changes directly to ice or ice to vapor. (frost)
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Sublimation
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a processs in which the temp of a gas (air) is changed without the addition or deletion of heat energy.
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Adiabatic cooling/heating
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Dry cooing rate:
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-3 deg. ber 1000 ft occurs when air is rising an not saturated.
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Moist cooling rate
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1.5 degrees per 1000ft occurs after saturation takes place in rising air.
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an altitude at which the temp. of the air inside the pa4cel of air being lifted becomes the same as the surrounding air because of the release of the latent heat of condensation.
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Lever of Free Convection (LFC)
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formation of clouds is the direct result of _________
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Saturation (generally the result of cooling)
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clouds les than 6500 feet
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Cu
Cb St Sc Ns |
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clouds middle 6500ft to 20,000ft
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As
Ac |
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High clouds aboce 20,000ft
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Ci
Cs Cc |
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What are the 2 basic types of clouds?
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Cumulous
Stratus |
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Cause of frontal weather
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the lifting of warm moist air by colder more dense air (all fronts have a temp. inversion)
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Cold fornt slope ratio:
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1:80
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what type of front has the worst weather?
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Cold
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What direction do cold fronts move? Warm Fronts?
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NW to SE
Sw to NE |
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What is the slope of the warm front? Speed?
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1:200
15Kts |
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What is the average speed of a cold front? When is a squall line possibly formed?
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25kts (50 miles wide)
>25kts |
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Stationary front is similar to a ? Speed? movement?
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Warm front
0-5kts unpredictable |
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Flight procedure for occlusion?
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avoid by 50 miles
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Fligh proced. for warm fronts and stationary fronts?
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have alternates
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Cold front flight proced.?
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Don't go
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What type fog is caused by radiation cooling and light winds 2-5 kts cooling lower layer of air to near dew point. Dissipates after sunrise and winds> 5kts
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Radiation fog
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what type fog requires warm, moist air flowing over a cool surface?
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Advection fog
(deep moving widespread winds up to 15kts.) |
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What type fog cools adiabatically?
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upslope fog
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What fog cools rapidly at night and becomes more dense
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Valley fog
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Ice formed ) to -20 deg.
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Rime ice
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Ice formed 0 to -10 deg.
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clear ice
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Freezing rain is most common with ____ fronts.
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Warm
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Clear ice formation on Blades will result in a loss of What?
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Autorotative capability
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2 types of thunderstorms
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Air mass - thermal convection
-orographic(mechanical) Frontal - cold front, squall line, warm front |
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What stage of a thunderstorm is most severe?
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Mature stage
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Procedures for Air mass thunderstorm?
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Circumnavigate by at least 20 miles
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in a mountain wave the most dangerous feature is the what?
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Downdraft on the leeward side (turbulence)
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What is the most familiar sign of mountain wave conditions?
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Lenticular clouds formed on the crest of the waves.
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Where do rotor clouds form on mountain waves? (dark ominous, rolling appearance, stationary)
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at height
of mountain ridge |
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When approaching mountain range what is the procedure for mountain wave crossing?
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approach 45 deg angle, altitude as high as practicable clear of clouds
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What are the 3 types of weather reports?
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METAR, SPECI, COR
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Weather descriptors:
BC FZ SH TS |
BC - patches
FZ - Supercooled/ freezing SH - showers TS - Thunderstorms |
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Obstructions to visibility are reported when?
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when < 7sm
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Obstructions abbrev.
FG HZ FU DU BR |
FG - fog
HZ - haze FU - smoke DU - dust BR - mist |
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Intensity indicators
+ _ |
no sign - moderate
+ heavy - Light |
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the lowest layer of clouds or obscuring phenomena that is reported as Broken or Overcast.
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Ceiling
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METAR reports are put out when?
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hourly
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Weather charts are transmitted every ___ hrs.
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3 hrs
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Info for WX charts are updated from that report?
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METAR
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Isobar spacing is usually ____ millibars?
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4
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in the weather depiction guide, visibility in excess of 6 sm are/not ploted.
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Not plotted
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Radar summary charts are issured how often?
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Every hour
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A Terminal Aerodrome Forecast is isued how many times per day?
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4
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TAF is a consise statement of the expected meteorological conditions at an airport usually for __ hours.
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24
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Winds aloft chart data is valid for __ hours.
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12
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on TAF "9999" means:
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Vis > 6 sm
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On Winds Aloft Chart "99" means:
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Winds Less than 5 knots - light and variable
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